1. Pre-Design
A. Appraisal
B. Design Brief
1.1. Obtain design brief
1.1.1. CIBSE guidance and tools
The building services engineer should be able to influence the design brief at an early stage in terms of energy efficiency, system options, sustainability, climate change, regulations etc. There are various ways to influence the brief and the following suggested guidance provides information relevant to some of the issues related to building design.
CIBSE Guide F “Energy Efficiency in Buildings” provides information on energy efficiency issues at various design stages, including information to be used at early design stages, such as the drivers for energy efficiency (chapter 1), setting energy objectives, criteria and targets, equipment and system selection (chapter 2) and developing a design strategy (chapter 3). Furthermore, Guide F provides general information on LZC technologies (chapter 5), control strategies (chapter 6) and heating and hot water design considerations (chapter 10). Part C of Guide F provides benchmarks of energy performance for various building applications and a series of CIBSE policy statements that reinforce the drivers for energy efficiency.
CIBSE Guide L “Sustainability” provides information on sustainability issues to help towards influencing the design brief (chapter 2), forming a sustainability strategy (chapter 3), including energy and low carbon strategy with reference to LZC technologies (§3.1), and adaptation to the impacts of climate change (§3.3).
Other CIBSE publications related to LZC technologies are the AM12 “Small-Scale Combined Heat and Power for Buildings”, Knowledge Series KS10 “Biomass Heating”, TM25 “Understanding Building Integrated Photovoltaics and TM38 “Renewable Energy Sources for Buildings” with an accompanied simple tool to assist in initial identification of the most promising renewable sources for a given project.
CIBSE KS11 “Green Roofs” explains the thermal properties of the green roofs that could also be used as roof insulation for reducing heat losses.
CIBSE Knowledge Series publication KS8 ”How to Design a Heating System” summarises the areas where the building services engineer should influence the design brief and presents the various system choices.
A more holistic approach of how to influence the design brief that combines energy efficiency, sustainability, cost, regulations, future performance; how certain design decisions could affect the above choices and their interrelations e.g. sustainability against capital, and whole life cost against building regulations requirements etc.
1.1.2. Weather data available for present climate conditions
At this pre-design stage of consulting with the client some general weather statistics based on location could be used towards influencing the design brief in terms of energy efficiency and system option.
CIBSE Guide A “Environmental Design” provides cold weather data for various UK locations (chapter 2, §2.3) as well as heating degree days (chapter 2, §2.5) to inform the heating strategy. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides summary statistics (§3.5), cold weather data (chapter 4, §4.1) and heating degree days (chapter 4, §4.3) for the same UK locations.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (www.ukcip.org.uk).
The user should be looking for present day statistics of occurrence of low temperatures, coincidence of low temperatures and wind speeds and coincidence of dry bulb and wet bulb temperatures, based on location.
The weather data available in the CIBSE guides are location specific but not site specific. The user should take under consideration that locality and microclimate can considerably affect design decisions. Local information could be acquired from city councils, local planning authorities, environment agency, met office etc.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could lead to the choice of lower external design temperatures than necessary.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
1.1.3. Weather data available for future climate conditions
At this pre-design stage of consulting with the client some general climate change statistics based on location could be used towards influencing the design brief in terms of climate change; possible impacts on building and building site and designing for future conditions.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2 and chapter 4, §4.4) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE Guide L “Sustainability” summarises climate changes for one emissions scenario and for the same three locations.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for future trends of winter temperatures coincident low temperatures and wind speeds and coincident dry bulb and wet bulb temperatures, based on location.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
The CIBSE climate change data (Guides A, J, L and TM34) are available for three locations only (London, Manchester and Edinburgh).
TM34 presents trends of low temperatures and coincident dry bulb and wet bulb temperatures but there are no wind data available due to the lack of suitable algorithm to produce hourly wind speed data from the available UKCIP02 daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty is higher than for example for the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
1.1.4. Other useful references
Environment Agency’s Flood Map resource at: http://www.environment-agency.gov.uk/subjects/flood/826674/829803
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
1.1.5. Input from members
1.2. Identify client and building user needs and requirements
1.2.1. CIBSE guidance and tools
The building services engineers should be able to identify and acquire client requirements to be used while putting together the brief, so as to optimise design in terms of sustainability, energy efficiency, regulations, future needs etc. Such requirements could include budget, required performance, attitude to risk, health and safety requirements etc.
An example of listing client and user needs and requirements is presented in CIBSE Knowledge Series publication KS8 “How to Design a Heating System”. Such a list could potentially be composed or customised by designers by using a series of CIBSE publications such as Guide A “Environmental Design” for internal environment requirements, Guide F “Energy Efficiency in Buildings” for energy efficiency requirements, Guide L “Sustainability”, Guide H “Building Control Systems” for control requirements etc.
CIBSE could offer a checklist of all relevant needs and requirements that the engineer could advise towards reaching objectives described in task 1.1.
1.2.2. Other useful references
1.2.3. Input from members
1.3. Refer to feedback and lessons learned from previous projects
1.3.1. CIBSE guidance and tools
The building services engineers should be able to keep in touch with previous projects in order to learn from them and improve their design methods. Some guidance on energy audits and surveys is included in Guide F, chapter 18.
Facilities managers (FMs) are usually responsible for the management of the building services and energy use in a building and have access to performance and energy use data. Liaising with the FMs during design process could provide useful information about the future operation and maintenance needs of a building and its services. Limited information on facilities and energy management is provided in Guide F, chapter 15.
Further guidance could include advice on possible channels and actions through which the design team could revisit or keep in touch with previous projects. Perhaps some research could be done in current practices.
Could CIBSE influence client perception of the value of monitoring and feedback? For example in some current projects monitoring and feedback is used as an educational process.
Further guidance could concentrate on encouraging integration with Facilities Management (FM), e.g. FM participation during design stages.
1.3.2. Other useful references
1.3.3. Input from members
1.4. Gather information about site, including utilities provision and fuel options
1.4.1. CIBSE guidance and tools
The building services engineers should make sure that they acquire all site specific information that could influence the design decisions.
The CIBSE Knowledge Series publication KS8:”How to Design a Heating System” (chapter 3, §3.2) contains a list of site specific information.
CIBSE Guide F “Energy Efficiency in Buildings” provides some general site considerations (chapter 4, §4.1).
CIBSE Guide L “Sustainability”, chapter 3, provides information on site analysis, in relation to energy use (§3.1), and on assessment of flood risk (§3.4), site accessibility (§3.6) and impacts on local environment and community (§3.11). Climate changes are summarised in Guide L for three locations in order to assist in forming adaptation solutions to climate change.
Fuel choices for heating are included in CIBSE Guide B “Heating, Ventilation, Air Conditioning and Refrigeration”, chapter 1, §1.6, in Guide F, chapter 5, §5.2 and in KS10 “Biomass Heating”.
A comprehensive checklist of all relevant site specific information and their possible sources e.g. city councils, local planning authorities, environment agency, met office, site visits etc could help at this stage.
1.4.2. Weather data available for present climate conditions
At this pre-design stage of gathering site information, statistics on cold weather events based on location could assist on the choice of external design winter conditions.
CIBSE Guide A “Environmental Design” provides cold weather data for various UK locations (chapter 2, §2.3) as well as heating degree days (chapter 2, §2.5) to inform the heating strategy. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides summary statistics (§3.5), cold weather data (chapter 4, §4.1) and heating degree days (chapter 4, §4.3) for the same UK locations.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends, including days of frost, based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk).
The user should be looking for site specific climate/weather trends/extremes of occurrence of low temperatures, coincidence of low temperatures and wind speeds and coincidence of dry bulb and wet bulb temperatures. Furthermore, the user should be looking for site specific flooding/drought and frost occurrences that could affect some design decisions, such as the access to the building for fuels etc. The weather data available at the CIBSE guides are location specific but not site specific. The user should take under consideration that locality and microclimate can considerably affect design decisions. Local information could be acquired from city councils, local planning authorities, environment agency, met office etc.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of lower external design temperatures than necessary.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
1.4.3. Weather data available for future climate conditions
At this pre-design stage of gathering site information, trends of future cold weather events based on location could assist on the choice of external design winter conditions over the lifetime of the building. Such information could help in forming a flexible heating strategy that could inspire future low/zero energy use for heating.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2 and chapter 4, §4.4) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE Guide L “Sustainability” summarises climate changes for one emissions scenario and for the same three locations.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for future site specific climate/weather trends/extremes of occurrence of low temperatures, coincident low temperatures and wind speeds and coincident dry bulb and wet bulb temperatures.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
The CIBSE climate change data are available for three locations only (London, Manchester and Edinburgh).
TM34 presents trends of low temperatures and coincident dry bulb and wet bulb temperatures but there are no wind data available due to the lack of suitable algorithm to produce hourly wind speed data from the available UKCIP02 daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty in higher than for example for the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
1.4.4. Other useful references
Environment Agency’s Flood Map resource at: http://www.environment-agency.gov.uk/subjects/flood/826674/829803/
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: eca.knmi.nl
BRE (1990) ‘Climate and Site Development. Part 2: Influence of Microclimate’
1.4.5. Input from members
1.5. Obtain information on use of building, occupancy hours and on possible building form, fabric, etc.
1.5.1. CIBSE guidance and tools
The building services engineers should be able to acquire all building related information such as form and fabric details, building use and occupancy patterns, etc. An example of listing building specific information is presented in the CIBSE Knowledge Series publication KS8 “How to Design a Heating System” (§ 3.2).
CIBSE could further develop a checklist and guidance on where/how to acquire the relevant information e.g. client’s brief, by further questioning the client, design plans and details, etc.
1.5.2. Other useful references
1.5.3. Input from members
1.6. Establish and confirm design requirements from Regulations, Codes of Practice etc.
1.6.1. CIBSE guidance and tools
The building services engineers should be able to refer to all regulations, codes and standards that relate to the individual project. The most up-to-date references and links to specific regulations and codes are included in CIBSE Guide L “Sustainability”. Legislation regarding health issues associated with the building services could also be found in CIBSE TM40 “Health Issues in Building Services”.
CIBSE could further develop a comprehensive and dynamic list of all necessary documents and where to find them, download them etc, as well as possible future developments and updates.
1.6.2. Other useful references
1.6.3. Input from members
1.7. Establish requirements for use of on-site renewables
1.7.1. CIBSE guidance and tools
The building services engineers should be able to establish requirements for the use of LZC technologies e.g. check infrastructure, financing, environmental impact, planning requirements etc. CIBSE Guide L “Sustainability” provides guidance on LZC technologies options, environmental impact, current government targets and cost. Further guidance on the requirements for the installation and operation of LZC technologies could also be found in AM12 “Small-Scale Combined Heat and Power for Buildings”, Knowledge Series KS10 “Biomass Heating”, TM25 “Understanding Building Integrated Photovoltaics” and TM38 “Renewable Energy Sources for Buildings”.
Guidance on potential impact of future developments of the surrounding area that could affect the effectiveness of the LZC technologies – e.g. future high buildings will affect solar & daylight availability, change in land use could improve performance, etc. CIBSE could further develop a comprehensive and dynamic list of all relevant documents and/or where to find them e.g. county councils, building regulations, application documents, etc.
1.7.2. Other useful references
Grants available for installing renewables: http://www.clear-skies.org/
‘Integrating renewable energy into new developments: Toolkit for planners, developers and consultants’: http://www.london.gov.uk/mayor/environment/energy/london_renew.jsp
Energy Saving Trust: http://www.energysavingtrust.org.uk/generate_your_own_energy
1.7.3. Input from members
2. Preliminary design
C. Concept
D. Design development
2.1. Establish the key design data and parameters that relate to the design of the heating system, including building air tightness data, and the potential use of renewables
2.1.1. CIBSE guidance and tools
The building services engineer should look for guidance on how to establish internal and external design conditions in order to inform the design and sizing of the heating system e.g. comfort requirements, weather data etc.
CIBSE Guide A “Environmental Design” provides comfort criteria for design (chapter 1), surface condensation and mould growth design criteria (chapter 7, §7.6 and §7.7) and other health issues associated with building services (chapter 8).
CIBSE TM40 “Health Issues in Building Services “ also provides comprehensive guidance on health issues associated with the operation and maintenance of building services.
The CIBSE Knowledge Series publication KS6 “Comfort” explains internal comfort criteria.
The CIBSE Knowledge Series publication KS8 ”How to Design a Heating System” summarises internal design criteria for various applications (3.3) and explains how the choice of internal and external design conditions can substantially impact on system performance.
CIBSE TM23 “Testing Buildings for Air Leakage” provides guidance on air leakage tests.
CIBSE Guide F “Energy Efficiency in Buildings” (chapter 5) and Guide L “Sustainability” (chapter 3, §3.1 and chapter 5, §5.1) provide general information on LZC technologies and design requirements.
Other CIBSE publications related to renewable technologies are the AM12 “Small-Scale Combined Heat and Power for Buildings”, KS10 “Biomass Heating”, TM25 “Understanding Building Integrated Photovoltaics and TM38 “Renewable Energy Sources for Buildings” with an accompanied simple tool to assist in initial identification of the most promising renewable sources for a given project.
The guidance is comprehensive in relation to internal design criteria.
Even though TM23 covers air leakage testing methods (post construction) further guidance on methods to minimise air leakage at design stage could also be beneficial.
2.1.2. Weather data available for present climate conditions
Weather data at this preliminary design stage should be used towards deciding on the external conditions for designing the heating system. Data gathered at pre-design stage (task 1.4) could be analysed based on risk, building form and with client involvement in order to establish external design conditions.
CIBSE Guide A “Environmental Design” provides cold weather data for various UK locations (chapter 2, §2.3) as well as heating degree days (chapter 2, §2.5) to inform the heating strategy. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides summary statistics (chapter 3, §3.5), cold weather data (chapter 4, §4.1) and heating degree days (chapter 4, §4.3) for the same UK locations.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
Solar and wind data in Guide A (chapter 2, §2.7 and §2.8) and Guide J (chapter 5 and chapter 6) as well as the maps of average wind speed in the UKCIP08 recent trends report could be used for assessing potential use of renewables.
The user should be looking for percentage of certain conditions exceeded, such as low temperatures, coincident low temperatures and wind speeds and coincident dry bulb and wet bulb temperatures, based on location.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of lower external design temperatures than necessary.
Site specific information should be acquired for assessing potential use of renewables e.g. local wind, sunshine availability and elements blocking the sun around the site etc. Local information could be acquired from city councils, local planning authorities, environment agency, met office etc. and by site visits and discussions with client.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
2.1.3. Weather data available for future climate conditions
Climate change information at this preliminary design stage should be used towards deciding on the external conditions for establishing the heating strategy over the lifetime of the building. Data gathered at pre-design stage (task 1.4) could be analysed based on risk, building form and with client involvement in order to establish external design conditions incorporating climate change.
Climate change information could also be used here to inform future potential use of renewables; for example, examining the potential of replacing a conventional heating plant with a LZC technology, due to reduced future heating demand.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2 and chapter 4, §4.4) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE Guide L “Sustainability” summarises climate changes for one emissions scenario and for the same three locations.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of certain conditions exceeded in the future, such as low temperatures, coincidence of low temperatures and wind speeds and coincidence of dry bulb and wet bulb temperatures, based on location.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
CIBSE climate change data are available for three locations only (London, Manchester and Edinburgh).
The data available in TM34 can be used towards establishing future external design conditions, but there are no wind data available due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408 provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty is higher than for example for the temperature and rainfall changes. The daily average wind speed and cloud cover changes in the UKCIP02 scientific report could also be used to assess potential use of renewables in the future.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
2.1.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
The Building Regulations second tier document “Low or Zero Carbon Energy Sources: Strategic Guide” provides a simplified calculation tool for assessing the reduction in carbon emissions through the use of LZC technology: http://www.planningportal.gov.uk/uploads/br/BR_PDF_PTL_ZEROCARBONfinal.pdf
Geological surveys at the British Geological Survey: http://www.bgs.ac.uk/
Grants available for installing renewables: http://www.clear-skies.org/
‘Integrating renewable energy into new developments: Toolkit for planners, developers and consultants’: http://www.london.gov.uk/mayor/environment/energy/london_renew.jsp
Energy Saving Trust: http://www.energysavingtrust.org.uk/generate_your_own_energy
BRE (2006) “Achieving Airtightness”, three part set
BRE (1994) “Minimising Air Infiltration in Office Buildings”
2.1.5. Input from members
2.2. Develop room design data sheets
2.2.1. CIBSE guidance and tools
The use of room data sheets (RDS) to define detailed performance requirements during design and specification of new build or refurbishment of buildings is common practice.
Such room data sheets were developed for the Carbon Trust’s Low Carbon Design Initiative (LCDI) to provide support to clients of the construction industry and their consultants/advisers, in developing design specifications for new building designs that will achieve a low carbon impact. Copies of the existing peer reviewed room data sheets, overarching technical briefing and other LCDI documents could be acquired from http://www.carbontrust.co.uk/about/reports/lcdi.
It should be noted that the above documents were originally intended to deal with school buildings, and their application to other building types should be undertaken with caution and additional client input.
Furthermore, the building services aspects of the LCDI room data sheets were mainly composed using the information in CIBSE guidance, e.g. Guides A and B, and similarly the same guidance could be used to produce room data sheets for other building applications.
CIBSE could customise the above data sheets for use specifically by the building services engineers and for various types of buildings.
2.2.2. Other useful references
2.2.3. Input from members
2.3. Check that design parameters comply with legislation, energy targets etc.
2.3.1. CIBSE guidance and tools
Design parameters should be reviewed here to check that they comply with legislation and energy targets. A checklist of regulations, codes, standards etc, a sub category derived from the comprehensive list of task 1.6, could be used here that give specifications on design parameters and energy targets.
Guidance on ways to check the design is included in CIBSE Guide F “Energy Efficiency in Buildings”, chapter 13.
CIBSE could develop a dynamic list of possible documents to be used at this stage.
2.3.2. Other useful references
2.3.3. Input from members
2.4. Analyse building – establish fabric thermal performance and infiltration
2.4.1. CIBSE guidance and tools
The building services engineer should look for guidance, rules of thumb and calculation tools to estimate fabric U-values and infiltration rates. Furthermore, guidance on condensation and when it occurs and how to achieve an air-tight building could be used at this stage. Site and building data gathered during pre-design stage as well as external and internal design conditions from task 2.1 should also be used here.
CIBSE Guide A “Environmental Design” provides guidance, rules of thumb and manual calculation tools for the estimation of U-values of construction elements (chapter 3) and infiltration rates (chapter 4). Furthermore, infiltration rates could be estimated by using the guidance and tools in CIBSE AM10 “Natural Ventilation in Non-Domestic Buildings”.
Guide A also provides guidance, rules of thumb and manual calculation tools for assessing condensation risk (chapter 7). Psychrometric data from Guide C “Reference Data” (chapter 1) could also be used here for assessing condensation risk.
Some guidance in relation to building air tightness can be found in CIBSE TM23 “Testing Buildings for Air-Tightness”.
The guidance and tools for estimating U-values, infiltration and condensation risk is comprehensive at this design stage. Further guidance could be concentrating on how to achieve air-tightness through material, construction and operation of buildings.
2.4.2. Weather data available for present climate conditions
External design conditions established at task 2.1 should be used here to analyse fabric thermal performance and assess condensation risk. Although a single number is often used at this design stage (e.g. a single U-value etc) an analysis of fabric performance based on seasonal variability of the material properties could be beneficial. The values given for the thermal characteristics of the material are often measured under steady state conditions, which could mean that they significantly vary under variable weather conditions.
CIBSE Guide A “Environmental Design” provides cold weather data for various UK locations (chapter 2, §2.3) as well as wind data (chapter 2, §2.8) to inform ventilation design and infiltration assessment. CIBSE Guide J “Weather, Solar and Illuminance Data” also provides cold weather data (chapter 4, §4.1) and wind data (chapter 6) for the same UK locations.
Both Guides A (chapter 2, §2.3) and J (chapter 4, §4.1) also provide coincidence of dry and wet bulb temperatures and dew point temperature variation for assessing condensation risk.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends, including winter temperatures, rainfall and wind speeds, based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk).
The user should be looking for percentage of certain conditions exceeded, such as dry and wet bulb temperatures (for condensation analysis), wind speed and direction, solar radiation on a surface and other weather variable that might affect the performance of the building fabric, based on location.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of lower external design temperatures than necessary. Furthermore, warmer wetter winters could increase the risk of condensation occurrence.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
2.4.3. Weather data available for future climate conditions
Future external design conditions established at task 2.1 should be used here to analyse fabric thermal performance and assess future condensation risk. Although a single number is often used at this design stage (e.g. a single U-value etc) an analysis of fabric performance based on the seasonal variability of the material properties could be beneficial. The values given for the thermal characteristics of the material are often measured under steady state conditions, which could mean that they significantly vary under variable weather conditions and extreme events (e.g. increased rainfall, increased sunshine and temperatures etc).
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2 and chapter 4, §4.4) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE Guide L “Sustainability” summarises climate changes for one emissions scenario and for the same three locations.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of certain conditions exceeded, such as dry and wet bulb temperatures (for condensation analysis), wind speed and direction, solar radiation on a surface and other weather variables that might affect the performance of the building fabric, based on location.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
The data available in the CIBSE Guides A, J and L are general climate change trends that can inform towards future conditions, but can not be used readily in calculations.
The data available in TM34 can be used towards assessing future condensation risk, but there are no wind data available for infiltration calculations due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408 provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty is higher than for example for the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
2.4.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
BRE (2006) “Achieving Airtightness”, three part set
BRE (1994) “Minimising Air Infiltration in Office Buildings”
2.4.5. Input from members
2.5. Determine whether intermittent operation is likely and consider potential pre-heat requirements
2.5.1. CIBSE guidance and tools
The building services engineer should look for guidance, rules of thumb and calculation tools to assess thermal response of the building and to establish the need for intermittent operation of the heating system. Site and building data gathered during pre-design stage as well as external and internal design conditions from task 2.1 should also be used here.
CIBSE Guide A “Environmental Design” provides guidance, rules of thumb and manual calculation tools for estimating the intermittent operation of the heating system “correction of heating plant capacity for intermittent operation” (chapter 5, §5.10.3.3). Appendix 5.A8 provides the equations for calculating the factors for intermittent heating.
CIBSE Guide B “Heating, Ventilation, Air Conditioning and Refrigeration” provides guidance and manual calculation tools for estimating the plant size ratio related to intermittent heating (chapter 1, §1.4.7).
The guidance and tools for estimating intermittent operation are sufficient at this early design stage.
2.5.2. Weather data available for present climate conditions
In order to estimate pre-heat requirement for intermittent operation a good knowledge of frequency and duration of winter conditions is important. Design external conditions established at task 2.1 should be used here taking also under consideration the outcomes of the thermal analysis of the fabric (task 2.4).
CIBSE Guide A “Environmental Design” (chapter 2, §2.3) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 4, §4.1) provide cold weather data for various UK locations. The binned frequencies of occurrence of low 24-hout and 48-hour average temperatures and the wind data could be used to inform the intermittent operation of the heating system.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends, including winter temperatures and wind speeds, based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
The user should be looking for frequency and duration of average and extreme events of low winter temperatures and coincident wind speed and direction, based on location.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of lower external design temperatures than necessary.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
2.5.3. Weather data available for future climate conditions
In order to estimate pre-heat requirement for intermittent operation over the lifetime of the building, a good knowledge of frequency and duration of future winter conditions is important. Design external conditions established at task 2.1 should be used here taking also under consideration the outcomes of the thermal analysis of the fabric (task 2.4).
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2 and chapter 4, §4.4) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline
CIBSE Guide L “Sustainability” summarises climate changes for one emissions scenario and for the same three locations.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of occurrence of future events such as frequency and duration of low temperatures and coincident wind speed and direction, based on location.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
The data available in the CIBSE Guides A, J and L are general climate change trends that can inform towards future conditions, but can not be used readily in calculations.
The data available in TM34 can be used towards assessing future condensation risk, but there are no wind data available for infiltration calculations due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408 provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty in higher than for example for the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
2.5.4. Other useful references
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
2.5.5. Input from members
2.6. Estimate approximate building total heat loss to inform system selection process
2.6.1. CIBSE guidance and tools
The building services engineer should look for guidance, rules of thumb and calculation tools to assess heat losses through fabric and by infiltration and/or ventilation at early design stage. Site and building data gathered during pre-design stage as well as external and internal design conditions from task 2.1 should also be used here.
CIBSE Guide B “Heating, Ventilation, Air Conditioning and Refrigeration” provides guidance and manual calculation tools for estimating room and building heat losses (fabric and ventilation) (chapter 1, §1.3.3).
The guidance and tools for estimating heat losses are sufficient at this early design stage.
2.6.2. Weather data available for present climate conditions
In order to estimate heat losses a good understanding of the effect of external conditions on the fabric response and infiltration rates is important. Design external conditions used for tasks 2.4 and 2.5 should also be used here.
CIBSE Guide A “Environmental Design” (chapter 2, §2.3) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 4, §4.1) provide cold weather data for various UK locations. The binned frequencies of occurrence of low 24-hout and 48-hour average temperatures and the coincidence of low temperatures and high wind speeds could be used for the estimation of heat losses due to ventilation, infiltration and through fabric.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends, including winter temperatures and wind speeds, based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
The user should be looking for frequency and duration of low temperatures as well as coincidence of low temperatures and high wind speeds, based on location.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of lower external design temperatures than necessary.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
2.6.3. Weather data available for future climate conditions
In order to inform the long term heating strategy based on heat losses a good understanding of the effect of external conditions on the fabric response and infiltration rates is important. Design external conditions that incorporate climate change used for tasks 2.4 and 2.5 should also be used here.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2 and chapter 4, §4.4) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE Guide L “Sustainability” summarises climate changes for one emissions scenario and for the same three locations.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of occurrence of future events such as frequency and duration of low temperatures and coincident wind speed and direction, based on location.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
The data available in the CIBSE Guides A, J and L are general climate change trends that can inform towards future conditions, but can not be used readily in calculations.
The data available in TM34 can be used towards assessing future condensation risk, but there are no wind data available for infiltration calculations due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408 provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty in higher than for example for the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
2.6.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
2.6.5. Input from members
2.7. Consider zoning requirements
2.7.1. CIBSE guidance and tools
Appropriate zoning of spaces based on temperature variation, hours of operation, glazing levels and other material, etc. could help in maximising the efficiency of the heating system. The building services engineers should be able to identify zoning requirements and integrate them into the design of the systems.
A short introduction to zoning requirements for designing a heating system is given in CIBSE Guide B “Heating, Ventilation, Air Conditioning and Refrigeration” (§1.4.2.6) and in the Knowledge Series publication KS8 “How to Design a Heating System” (§3.5).
More in-depth guidance is needed to inform effective zoning that could optimize the efficiency of the heating system.
2.7.2. Other useful references
2.7.3. Input from members
2.8. Consider alternative heat source (fuel) and heating system options
2.8.1. CIBSE guidance and tools
The building services engineers should investigate the various fuel and heating options available based on environmental impact, cost, efficiency etc. A combination of systems that cover base and peak heating load could improve efficiency of the heating strategy.
Comprehensive guidance could be found in CIBSE Guide B “Heating, Ventilation, Air Conditioning and Refrigeration”, chapter 1, the Knowledge Series publications KS8 “How to Design a Heating System” and KS10 “Biomass Heating”, Guide F “Energy Efficiency of Buildings”, chapter 10 and AM12 “Small-Scale Combined Heat and Power for Buildings”.
Existing CIBSE guidance seems sufficient at this design stage.
2.8.2. Other useful references
2.8.3. Input from members
2.9. Establish contribution from renewable sources
2.9.1. CIBSE guidance and tools
The building services engineer should look for guidance and calculation tools to assess the potential use of renewable energy sources based on the building form, application and location. Cost and benefit analysis is essential at this point as well as assessing potential sources of financing the technologies, environmental impact and alternatives. Site and building data gathered during pre-design stage as well as key design parameters, such as external design conditions, from task 2.1 should also be used here.
CIBSE Guide F “Energy Efficiency in Buildings” (chapter 5) and Guide L “Sustainability” (chapter 3, §3.1 and chapter 5, §5.1) provide general information on LZC technologies and design requirements.
Other CIBSE publications related to renewable technologies are the AM12 “Small-Scale Combined Heat and Power for Buildings”, KS10 “Biomass Heating”, TM25 “Understanding Building Integrated Photovoltaics and TM38 “Renewable Energy Sources for Buildings” with an accompanied simple tool to assist in initial identification of the most promising renewable sources for a given project.
CIBSE is not offering at the moment a calculation tool for the analysis of contribution from renewable energy sources and LZC technologies. It is an opportunity for CIBSE to develop a calculation tool that would provide a quantitative analysis of the potential use of such technologies as well as a cost and benefit analysis, for specific projects.
2.9.2. Weather data available for present climate conditions
At this preliminary design stage a good knowledge of the site and the microclimate is essential towards analysing the potential of various renewable resources.
CIBSE Guide A “Environmental Design” (chapter 2, §2.7 and §2.8) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapters 5 and 6) provide solar and wind data for various UK locations.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
Solar and wind data in Guide A (chapter 2, §2.7 and §2.8) and Guide J (chapter 5 and chapter 6) could be used for assessing potential use of renewables as well as the maps of average wind speed in the UKCIP08 recent trends report.
The user should be looking for site specific weather data and local elements that could potentially affect the microclimate and/or the performance of renewable technologies.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of unlike external design conditions than those occurring.
The CIBSE weather data are location specific but not site specific. Site specific information should be acquired for assessing potential use of renewables e.g. local wind, sunshine availability and elements blocking the sun around the site etc. Local information could be acquired from city councils, local planning authorities, environment agency, Met office etc. and by site visits and discussions with client.
Guidance is required on the type of information needed for assessing potential of renewables and how to obtain such site specific information, e.g. Met Office, local weather station, city council archives etc.
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
2.9.3. Weather data available for future climate conditions
At this preliminary design stage a good understanding of the future weather trends and the microclimate of the site could help towards forming a strategy for improving the building’s carbon emissions by incorporating more LZC technologies.
CIBSE Guide A “Environmental Design” (chapter 2, §2.9) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 3, §3.2 and chapter 4, §4.4) provide climate change trends for various emissions scenarios, for three UK locations (London, Manchester and Edinburgh); changes are based on a 1961-1990 baseline.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
The user should be looking for probability of certain weather variables changing in the future that could potentially affect the performance of renewable technologies. For example increase sunshine hours will increase the use of solar renewable technologies.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Trends of temperatures and sunshine hours in TM34 can be used towards assessing future use of renewables, but there are no wind data available for wind technologies due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty in higher than for example for the temperature and rainfall changes.
The data in Guides A and J are not at the moment consistent. Climate change data in Guide A is in accordance with UKCIP02 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291), while Guide J data is in accordance with the previous version of UKCIP98 climate change scenarios (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=255).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
2.9.4. Other useful references
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
The Building Regulations second tier document “Low or Zero Carbon Energy Sources: Strategic Guide” provides a simplified calculation tool for assessing the reduction in carbon emissions through the use of LZC technology: http://www.planningportal.gov.uk/uploads/br/BR_PDF_PTL_ZEROCARBONfinal.pdf
Geological surveys at the British Geological Survey: http://www.bgs.ac.uk/
Grants available for installing renewables: http://www.clear-skies.org/
‘Integrating renewable energy into new developments: Toolkit for planners, developers and consultants’: http://www.london.gov.uk/mayor/environment/energy/london_renew.jsp
Energy Saving Trust: http://www.energysavingtrust.org.uk/generate_your_own_energy
2.9.5. Input from members
2.10. Consider operating, maintenance and control strategies, and building usage and layout data
2.10.1. CIBSE guidance and tools
The building services engineers should investigate the various control and operation strategy options based on the heating systems under consideration. A checklist of information required, e.g. building plans, space usage, comfort requirements etc, could be used here to inform the process.
CIBSE guidance on controls exists in Guide H “Building Control Systems”, Knowledge Series KS4 “Understanding Controls”, Guide F “Energy Efficiency in Buildings” (chapter 6). Guidance on noise and vibration controls for HVAC can be found in Guide B “Heating, Ventilation, Air Conditioning and Refrigeration”, chapter 5.
Furthermore, Guide B, chapter 1, and Guide F “Energy Efficiency of Buildings”, chapter 10, contain considerations on control, maintenance and operation options for a variety of heating systems.
Guidance on system maintenance and operation exists in CIBSE “Guide to Ownership, Operation and Maintenance of Building Services. Guide M “Maintenance Engineering and Management” also provides comprehensive guidance in the management, operation, maintenance and control of building services. Guide F Part B refers to management (chapter 15) and maintenance of building services (chapter 17) while the principles of building services management are analysed in the Knowledge Series publication KS5 “Making Buildings Work”.
CIBSE could provide a checklist of all requirements necessary for designing the control and operation strategy of the heating system.
2.10.2. Other useful references
2.10.3. Input from members
2.11. Assess options against client requirements, performance, risk, energy use etc.
2.11.1. CIBSE guidance and tools
The building services engineers should be able to follow a methodology for assessing the various options against a series of criteria set by the client, building regulations, standards etc. The assessment methods could include a series of consultations with the design team and the client, a prioritising strategy based on client’s brief etc. Assessing the various options identified could become critical when choosing between similar options.
CIBSE could provide a methodology for assessing options.
2.11.2. Other useful references
2.11.3. Input from members
2.12. Select proposed system
2.12.1. CIBSE guidance and tools
Based on the assessment of various options during task 2.11 the building services engineers should be able to identify the optimum solution based on client brief.
See task 2.11
2.12.2. Other useful references
2.12.3. Input from members
3. Design development
E. Technical design
3.1. Calculate space heat losses
3.1.1. CIBSE guidance and tools
The building services engineer should look for calculation tools to assess heat losses through fabric and infiltration and/or ventilation at this design stage.
CIBSE Guide A “Environmental Design” provides manual calculation tools for calculating room and building heat losses i.e. thermal responses of building structure and heat losses through structure and fabric (chapter 3), heat losses due to infiltration and ventilation (chapter 4, §4.6 and §4.7) and the CIBSE Simple Model for calculating total heat losses (chapter 5, §5.6.2). Also available in Guide A (Appendix 5.A3) are the Reference Model and the Basic Model. Appendix 5.A4 offers a quantitative comparison between the three models.
Computer based simulation tools, such as thermal models and CFD, could be used to assess building heat losses based on hourly external data and corresponding building performance. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
The differences in application of the manual calculation tools are not always defined clearly by the guidance. The fact that the calculation tools are often in various sections and Appendices also makes it harder to follow a given methodology. The quantitative analysis of the three steady-state models gives a comparative measure of margins between the models but still there is no guidance on the significance of these differences, for example by comparing with case study measurements.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine space temperature variation (model output) by varying the ventilation rates (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.1.2. Weather data available for present climate conditions
Detailed calculations should be part of this design stage using either manual or computer based calculation tools. Depending on the approach binned or hourly weather data that would best describe the average and extreme winter conditions should be used to examine the heat losses of the building.
CIBSE Guide A “Environmental Design” (chapter 2, §2.3) and CIBSE Guide J ‘Weather, Solar and Illuminance Data’ (chapter 4, §4.1) provide cold weather data for various UK locations. The binned frequencies of occurrence of low 24-hour and 48-hour average temperatures and the coincidence of low temperatures and high wind speeds could be used for the estimation of heat losses due to ventilation, infiltration and through fabric.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends, including winter temperatures and wind speeds, based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
The CIBSE Test Reference Years (TRY) are often used for the simulation of the thermal performance of buildings. These are hourly weather series over a year and for 14 different UK locations.
For the manual calculations the user should be looking for frequency and duration of average and extreme events of low winter temperatures as well as coincidence of low temperatures and high wind speeds, based on location.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of lower external design temperatures than necessary.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
3.1.3. Weather data available for future climate conditions
A better understanding of the thermal performance of the building under future conditions could inform low energy solutions over its lifetime. Detailed calculations should be part of this design stage using either manual or computer based calculation tools. Depending on the approach binned or hourly weather data that would best describe the average and extreme future winter conditions should be used to examine the heat losses of the building.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For manual calculations the user should be looking for probability of occurrence of future events such as frequency and duration of low temperatures and coincident wind speed and direction, based on location.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Furthermore, the data available in TM34 can be readily used in manual calculations, but there are no wind data available for calculating infiltration/ventilation heat losses due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty in higher than for example for the temperature and rainfall changes.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.1.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.1.5. Input from members
3.2. Assess ventilation requirements and provision
3.2.1. CIBSE guidance and tools
At this stage the building services engineer should look for guidance and calculation tools to assess ventilation and infiltration rates in order to:
The Ventilation Framework provides a detailed analysis of the stages towards designing the overall ventilation strategy.
CIBSE Guide B “Heating, Ventilating, Air Conditioning and Refrigerating” provides guidance on the issues related to the choice of ventilation strategy (chapter 2, §2.2), detailed analysis of the indoor air quality requirements for various applications (chapter 2, §2.3) and detailed analysis for the design of natural (chapter 2, §2.4.3) and mechanical (chapter 2, §2.4.4) ventilation systems. Furthermore, Appendix 2.A1 summarises the various techniques for assessing ventilation rates including the use of CFD and physical models.
CIBSE Guide A “Environmental Design” provides guidance and calculation methods for assessing room and building ventilation options, including natural, mechanical and mixed-mode ventilation (chapter 4), and infiltration rates.
CIBSE AM10 “Natural Ventilation in Non-Domestic Buildings” provides extensive guidance and calculation methods to assist in the design of the natural ventilation strategy.
CIBSE AM13 “Mixed Mode Ventilation” provides extensive guidance on the design of a mixed mode ventilation strategy, including rules of thumb to assess whether mixed mode ventilation is a possibility and the various options available.
CIBSE TM29 “HVAC Strategies for Well-Insulated Airtight Buildings” provide guidance on mechanical ventilation options in heated/cooled spaced.
Computer based simulation tools, such as thermal models and Computer Fluid Dynamics (CFD), could be used to assess building ventilation strategy based on hourly external data and corresponding building performance.
CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
AM10 (chapter 4) provides guidance on the use of CFD (§4.2.5), combination of thermal models and CFD (§4.2.6) and physical models (§4.3.7) for the analysis of the natural ventilation performance in a building. AM13 (chapter 10) suggests the combination of thermal modelling and CFD in order to better understand the performance of a mixed mode approach, while TM29, provides case studies where dynamic simulations were used in order to analyse the performance of a mechanical HVAC approach.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine space temperature variation (model output) by varying the ventilation rates (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.2.2. Weather data available for present climate conditions
Detailed calculations should be part of this design stage using either manual or computer based calculation tools. Depending on the approach binned or hourly weather data that would best describe the average and extreme winter conditions should be used to examine the ventilation rates of the building in relation to the heating strategy.
CIBSE Guide A “Environmental Design” (chapter 2, §2.3) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 4, §4.1) provide cold weather data for various UK locations. The binned frequencies of occurrence of low 24-hour and 48-hour average temperatures and the coincidence of low temperatures and high wind speeds could be used for natural and mixed mode ventilation analysis, and for estimating infiltration rates, in order to inform the design of the heating strategy. Moreover, the frequency distributions of wind by direction and by external temperature in Guide A (§2,8) and Guide J (chapter 6, §6.6) aim to assist in ventilation design.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends, including winter temperatures and wind speeds, based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
The CIBSE Test Reference Years (TRY) are often used for the simulation of the thermal performance of buildings. These are hourly weather series over a year and for 14 different UK locations.
For manual calculations the user should be looking for frequency distributions of average and extreme wind speeds by both direction and external temperature, based on location.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of lower external design temperatures than necessary.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities decisions will be made upon revising and further updating the data in Guides A and J.
3.2.3. Weather data available for future climate conditions
A better understanding of the ventilation potential of the building under future conditions could inform low energy solutions over its lifetime. Detailed calculations should be part of this design stage using either manual or computer based calculation tools. Depending on the approach binned or hourly weather data that would best describe the average and extreme future winter conditions should be used to examine the ventilation rates of the building in relation to the heating strategy.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For manual calculations the user should be looking for frequency distributions of average and extreme wind speeds by both direction and external temperature, with attached probability of occurrence, based on location.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Furthermore, the data available in TM34 can be readily used in manual calculations, but there are no wind data available for calculating infiltration/ventilation heat losses due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty in higher than for example for the temperature and rainfall changes.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.2.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.2.5. Input from members
3.3. Assess HWS provision
3.3.1. CIBSE guidance and tools
The building services engineers should be using guidance on hot water requirements and regulations, and tools to estimate hot water demand.
Guidance and tables of estimates of hot water demand based on building application exist in CIBSE Guide G “Public Health Engineering”, chapter 2, and Guide F “Energy Efficiency in Buildings”, chapter 10. Also see task 2.9 where the contribution from renewables is analysed.
CIBSE could develop tools for a more precise calculation of hot water demand especially when demand is met by renewable energy sources.
3.3.2. Other useful references
3.3.3. Input from members
3.4. Check system selection provision still appropriate
3.4.1. CIBSE guidance and tools
The building services engineers should be using assessment methods to evaluate the option selected at task 2.12. The evaluation should be based on results from detailed calculations performed in the previous tasks of stage 3.
CIBSE could provide a checklist of criteria for the evaluation of selected systems.
3.4.2. Other useful references
3.4.3. Input from members
3.5. Determine pre-heat requirements
3.5.1. CIBSE guidance and tools
The building services engineer should be able to analyse the thermal inertia of the building during cold spells and when in intermittent operation by using dynamic tools. Guidance suggested in task 2.5 and outcomes from completing the task could also be used here.
Computer based simulation tools, such as thermal models could be used to analyse building thermal response and assess pre-heat requirements, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine space temperature variation (model output) by varying the ventilation rates (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.5.2. Weather data available for present climate conditions
At this design development stage a good understanding of the thermal response of the building and as a result any pre-heating required is essential in order to size the heating system. This is possible by the use of computer based tools that use hourly weather series to describe the response of the building. Average and extreme winter conditions should be used to examine the thermal inertia of the building and inform the sizing of the heating system.
The CIBSE Test Reference Years (TRY) are often used for the simulation of the thermal performance of buildings. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.5.3. Weather data available for future climate conditions
A detailed analysis of the thermal response of the building and as a result any pre-heating required under future conditions could inform low energy solutions over its lifetime. This is possible by the use of computer based tools that use hourly weather series to describe the response of the building. Average and extreme future winter conditions should be used to examine the thermal inertia of the building and inform the sizing of the heating system.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.5.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.5.5. Input from members
3.6. Consider suitable emitter positions and connections
3.6.1. CIBSE guidance and tools
The building services engineers should be using guidance on heat emitter positioning and the various choices available.
Some guidance exists in CIBSE Guide A “Environmental Design”, chapter 5, Guide F “Energy Efficiency in Buildings”, chapter 10 and Guide B “Heating, Ventilation, Air Conditioning and Refrigeration”, chapter 1.
CIBSE guidance on designing distribution networks is mostly in the form of general recommendations but there is not much practical advice. For example guidance in the form of schematics could be useful.
3.6.2. Other useful references
3.6.3. Input from members
3.7. Check distribution layout considering balancing and regulating requirements
3.7.1. CIBSE guidance and tools
The building services engineers should be using guidance on heat distribution system layout requirements.
Guidance exists in Guide F “Energy Efficiency in Buildings”, chapter 10, and the Knowledge Series publications KS7 “Variable Flow Pipework Systems” and KS9 “Commissioning Variable Flow Pipework Systems”. Reference data on heat transfer and flow of fluids in pipes and ducts could be found in CIBSE Guide C “Reference Data”, chapters 3 and 4.
CIBSE guidance seems sufficient.
3.7.2. Other useful references
3.7.3. Input from members
3.8. Consider circuit layouts and connections and pumping choices – variable or constant volume
3.8.1. CIBSE guidance and tools
The building services engineers should be using guidance on circuit design and various pumping choices.
Guidance exists in CIBSE Guide B “Heating, Ventilation, Air Conditioning and Refrigeration”, chapter 1, Guide F “Energy Efficiency in Buildings”, chapter 10, and the Knowledge Series publications KS7 “Variable Flow Pipework Systems” and KS9 “Commissioning Variable Flow Pipework Systems”.
CIBSE guidance seems sufficient.
3.8.2. Other useful references
3.8.3. Input from members
3.9. Develop control requirements
3.9.1. CIBSE guidance and tools
The building services engineers should be using guidance on controls and control strategies for the heating systems selected.
Guidance exists in CIBSE Guide H “Building Control Systems”, Knowledge Series KS4 “Understanding Controls”, Guide F “Energy Efficiency in Buildings”, chapter 6 and 10. Guide B “Heating, Ventilation, Air Conditioning and Refrigeration”, chapter 1, also present control requirements relative to the system options presented. Guidance on noise and vibration controls for HVAC can be found in Guide B “Heating, Ventilation, Air Conditioning and Refrigeration”, chapter 5.
CIBSE guidance seems sufficient.
3.9.2. Other useful references
3.9.3. Input from members
3.10. Size and select emitters and distribution network and determine any distribution losses
3.10.1. CIBSE guidance and tools
The building services engineers should be using guidance and tools for selecting and sizing emitters and distribution network
Guidance on system selection is included in CIBSE Guide A “Environmental Design”, chapter 5, Guide F “Energy Efficiency in Buildings”, chapter 5, Guide B “Heating, Ventilation, Air Conditioning and Refrigeration”, chapter 1 and Guide F “Energy Efficiency in Buildings”, chapter 9.
A model for sizing emitters is included in Guide A, chapter 1 (§1.5).
Guidance and calculation tools to estimate heat transfer and distribution losses could be found in Guide B, chapter 1 (§1.5.5.3), Guide A, chapter 5, and Guide C “Reference Data”, chapter 3.
CIBSE guidance on designing distribution networks is mostly in the form of general recommendations but there is not much practical advice. For example guidance in the form of schematics could be useful.
3.10.2. Other useful references
3.10.3. Input from members
3.11. Determine other loads such as HWS and process
3.11.1. CIBSE guidance and tools
The building services engineers should be using guidance and tools for the estimation of hot water and process requirements.
Guidance exists in CIBSE Guide G “Public Health Engineering”, chapter 2 and Guide F “Energy Efficiency in Buildings”, chapter 10. Also consider results from task 3.3.
CIBSE could develop tools for a more precise calculation of hot water demand especially when demand is met by renewable energy sources.
Also, there is no guidance for the estimation of other process requirements e.g. drying facilities, manufacturing processes etc.
3.11.2. Other useful references
3.11.3. Input from members
3.12. Calculate main heating loads
3.12.1. CIBSE guidance and tools
The building services engineer should be able to calculate the heating loads of the spaces based on application, internal heat gains, heat losses and pre-heat requirements calculated in previous tasks, by using manual or computer based tools. Outputs from tasks 3.1, 3.2, 3.3 and 3.5 to be used here.
The guidance and tools in CIBSE Guide A “Environmental Design” (chapter 5, §5.6.2 and §5.10.3) could be used for the calculation of the heating loads of spaces in a building, under steady-state conditions.
Computer based simulation tools, such as thermal models could be used to analyse the building heating demand based on thermal inertia and assess heating loads, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
Further guidance could concentrate on how to avoid oversizing when sizing the heating plant.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine space temperature variation during long periods of cold weather (model output) by varying the available heating load (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.12.2. Weather data available for present climate conditions
In order to calculate the heating loads of a building either manual or computer tools can be used. Hourly weather series often used by computer tools provide knowledge of the dynamic performance of a building in response to external conditions. Such an approach could help in avoiding over sizing of the heating system. Average and extreme winter conditions should be used to examine the heating loads of the building and inform the sizing of the heating system.
CIBSE Guide A “Environmental Design” (chapter 2, §2.3) and CIBSE Guide J “Weather, Solar and Illuminance Data” (chapter 4, §4.1) provide cold weather data for various UK locations. The binned frequencies of occurrence of low 24-hour and 48-hour average temperatures and the coincidence of low temperatures and high wind speeds could be used to assess heating loads required in a space.
The UKCIP08 publication “The Climate of the United Kingdom and Recent Trends” provides climate trends, including winter temperatures and wind speeds, based on observed data (two baselines 1961-1990 and 1971-2000) presented at a 5km x 5km resolution, in a form of graphs and maps. The publication is freely available by UKCIP (http://www.ukcip.org.uk/).
The CIBSE Test Reference Years (TRY) are often used for the simulation of the thermal performance of buildings. These are hourly weather series over a year and for 14 different UK locations.
For manual calculations the user should be looking for frequency distributions of average and extreme wind speeds by both direction and external temperature, based on location.
The data in Guides A and J are not at the moment consistent. Weather data in Guide A have been updated to a more recent baseline (1983-2002), while data in Guide J are based on an earlier baseline (1976-1995). The most up-to-date weather data currently available by CIBSE is located in Guide A, chapter 2. Although the weather data in Guide A have been recently updated, Guide J provides the background information on their production and selection processes that could enhance the understanding of the uncertainty associated with their use and as a result lead to more robust design decisions.
The baselines used for the production of weather data in Guides A and J do not include current manifestations of climate change, which could arguably lead to the choice of lower external design temperatures than necessary.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
Depending on the outputs of the above activities, decisions will be made upon revising and further updating Guide J.
3.12.3. Weather data available for future climate conditions
A detailed analysis of the heating loads of the building under future conditions could inform low energy solutions over its lifetime. Either manual or computer tools can be used. Hourly weather series often used by computer tools provide knowledge of the dynamic performance of a building in response to external conditions. Average and extreme winter conditions should be used to examine the future heating loads of the building and inform the sizing of the heating system.
CIBSE TM34 “Weather Data with Climate Change Scenarios” provide climate change data in the same format as in Guide J for use in manual calculations to assess future system and building performance.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For manual calculations the user should be looking for frequency distributions of average and extreme wind speeds by both direction and external temperature, with attached probability of occurrence, based on location.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series for building design are based on UKCIP02 scenarios and are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326.
Furthermore, the data available in TM34 can be readily used in manual calculations, but there are no wind data available for calculating infiltration/ventilation heat losses due to the lack of suitable algorithm to produce hourly wind speed data from the available daily averages (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291).
The UKCIP02 scientific report (http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=353&Itemid=408) provides daily average wind speed changes, but extra caution should be taken when using these data since the associated uncertainty in higher than for example for the temperature and rainfall changes.
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.12.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.12.5. Input from members
3.13. Analyse load diversity and pre-heat requirement and determine the total heating load
3.13.1. CIBSE guidance and tools
The building services engineer should be looking for guidance in the use of dynamic simulation tools in order to analyse load diversity and pre-heat requirements based on external conditions, building fabric and application. The load diversity analysis could identify integrated solutions for heating for example covering base load, peak load and contingency load with a combination of LZC technologies and boiler units.
Outputs from tasks 3.5 and 3.12 could also be used here.
Computer based simulation tools, such as thermal models could be used to analyse load diversity in a building and pre-heat requirements, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine pre-heat period during long periods of cold weather (model output) by varying the fabric or window characteristics of the space (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.13.2. Weather data available for present climate conditions
At this advanced design stage a detailed knowledge of the thermal performance of the building is essential in order to finalise the heating system selection and sizing. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. Extreme winter conditions should be used to examine the thermal performance of the building and inform the sizing of the heating plant.
The CIBSE Test Reference Years (TRY) are often used for the simulation of the thermal performance of buildings. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.13.3. Weather data available for future climate conditions
At this advanced design stage a detailed knowledge of the thermal performance of the building over its lifetime is essential in order to finalise the heating strategy. Hourly weather series often used by computer tools provide knowledge of the dynamic performance of a building in response to external conditions. Future extreme events should be used to examine the thermal performance of the building and inform the heating strategy.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.13.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.13.5. Input from members
3.14. Consider any standby and future requirement
3.14.1. CIBSE guidance and tools
The building services engineers should be using guidance on issues related to assessing standby capacity, e.g. risk assessment, risk of oversizing etc.
Some introduction exists in CIBSE Knowledge Series publication KS8 “How to Design a Heating System”.
Further guidance is needed on including standby capacity when sizing the heating plant, while avoiding oversizing.
3.14.2. Other useful references
3.14.3. Input from members
3.15. Determine number of boilers/modules required and size and select main plant
3.15.1. CIBSE guidance and tools
The building services engineer should be looking for guidance on the selection of heat sources and heating plants as well as tools for sizing them. Dynamic simulation tools could be used for plant sizing based on hourly building thermal performance. Outcomes from tasks 3.11, 3.12, 3.13 and 3.14 could be used here. Alternatively, in case dynamic simulations were used to complete tasks 3.12 and 3.13, the results (based on the computer model used) could also incorporate output from plant sizing calculation.
CIBSE Guide B “Heating, Ventilating, Air Conditioning and Refrigerating” provides guidance on heating system selection (chapter 1, §1.4 and §1.5), while CIBSE Guide F “Energy Efficiency in Buildings” provides guidance on the energy efficiency issues related to the selection of heating sources and plant sizing (chapter 10).
Guide F, chapter 5, also provides guidance on renewable and LZC heating sources such as geothermal heating (§5.1.12), passive solar design (§5.1.11), solar water heating panels (§5.1.9) and CHP (§5.3). CIBSE AM12 “Small-Scale Combined Heat and Power for Buildings” provides a more detailed guidance on the design and operation of CHPs. Information gathered in task 2.9 could also be used here.
Computer based simulation tools, such as thermal models could be used to size central plants, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
Further guidance on integrated solutions could be useful, for example covering base load, peak load and contingency load with a combination of LZC technologies and boiler units.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine internal temperature variation, during long periods of cold weather, (model output) for variable occupancy (model input); is the heating capacity still sufficient. Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.15.2. Weather data available for present climate conditions
Computer tools are normally used at this design stage to size the heating plant and boilers/modules of the building. Hourly weather series often used by the computer tools provide knowledge of the dynamic performance of a building in response to external conditions. Extreme events should be used to examine the capacity of the plant to provide thermal comfort conditions.
The CIBSE Test Reference Years (TRY) are often used for plant sizing. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.15.3. Weather data available for future climate conditions
Computer tools are normally used at this design stage to size the heating plant and boilers/modules of the building. Hourly weather series often used by the computer tools provide knowledge of the dynamic performance of a building in response to external conditions. The capacity of the heating system / strategy could be examined under future extreme events in order to provide a flexible solution over the lifetime of the building.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.15.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.15.5. Input from members
3.16. Finalise controls
3.16.1. CIBSE guidance and tools
Guidance and outcomes from tasks 2.10 and 3.9 could be used here in order to finalise the control strategy of the building. Dynamic simulation tools could also be used for more complex building form and heating strategy design in order to finalise control requirements, for example when base load and pick load are covered by different heating sources.
CIBSE Knowledge Series KS4 “Understanding Controls” provides an introduction and overview of control systems and related issues. Chapter 6 of CIBSE Guide F “Energy Efficiency in Buildings” and CIBSE Guide H “Building Control Systems” provide comprehensive guidance on control selection and operation.
CIBSE Guide B “Heating, Ventilating, Air Conditioning and Refrigerating” provides guidance on controls for various heating systems (chapter 1), while Guide F provides guidance on controls for improving the energy efficiency of various heating options (chapter 10).
Computer based simulation tools, such as thermal models could assist in finalising the control strategy of a building, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine internal humidity levels (model output) for variable occupancy (model input); are the controls responding sufficiently. Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.16.2. Weather data available for present climate conditions
Based on the complexity of building form and services the control strategy could be fine tuned with the use of computer tools. Hourly weather series often used by the computer tools provide knowledge of the dynamic performance of a building in response to external conditions. Control requirements for temperature and humidity to avoid condensation could be established based on simulation outcomes.
The CIBSE Test Reference Years (TRY) are often used for building simulation. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.16.3. Weather data available for future climate conditions
Based on the complexity of building form and services the control strategy could be fine tuned with the used of computer tools. Hourly weather series often used by the computer tools provide knowledge of the dynamic performance of a building in response to external conditions. Future winter events could be used towards a flexible control strategy that could respond to future requirements of temperature and humidity, and increased condensation risk.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.16.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.16.5. Input from members
3.17. Check layouts and services co-ordination for clashes and ease of commissioning and maintenance
3.17.1. CIBSE guidance and tools
Guidance and outcomes from tasks 3.6 – 3.10 could be used here in order to check systems layout. Dynamic simulation tools could also be used for more complex building form and heating strategy design in order to check coordination of systems and avoid conflict of services e.g. heating and cooling at the same time, open windows for ventilation while heating is in operation etc.
Comprehensive guidance on commissioning and maintenance can be found in CIBSE “Guide to Ownership, Operation and maintenance of Building Services” and in Guide M “Maintenance Engineering and Management”. CIBSE Commissioning Codes B “Boilers” and C “Automatic Controls” and in the Knowledge Series KS9 “Commissioning Variable Flow Pipework Systems” concentrate on comissioning issues relative to the respective systems.
CIBSE Guide F “Energy Efficiency in Buildings” provides guidance on the commissioning process (chapter 14) and maintenance issues (chapter 17) in order to achieve expected efficiency.
Computer based simulation tools, such as thermal models should be used to check co-ordination and clashes of services, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine whether heating and cooling are operating at the same time (model output) for variable ventilation rates (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.17.2. Weather data available for present climate conditions
Co-ordination of building services is important for energy efficiency and cutting carbon emissions, and for cost effectiveness of systems operation. A detailed analysis of the systems’ operation based on the thermal performance of the building can point out the areas where possible clashes of services could exist. Computer tools could be used at this design stage to explore possible clashes of systems. Hourly weather series often used by computer tools provide knowledge of the dynamic performance of a building in response to external conditions. Systems’ clashes could be examined under certain weather events e.g. sunny but cold could encourage the opening of windows while the heating is on.
The CIBSE Test Reference Years (TRY) are often used for building simulation. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.17.3. Weather data available for future climate conditions
Future climate change conditions could differentiate the relationships between services and the maintenance strategy of the systems. A detailed analysis of the future operation of the systems could help identifying changes in operation and maintenance and incorporate solutions in the long term operational strategy of the building.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.17.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.17.5. Input from members
3.18. Review system design and check predicted system performance
3.18.1. CIBSE guidance and tools
At this advanced design stage a review of the overall system design against targets and client requirements could concentrate on various aspects of the design intent such as achieving required performance, energy efficiency at part load and control performance. This task will concentrate on confirming that the energy targets and the internal thermal comfort requirements are met.
Computer based simulation tools, such as thermal models, should be used to review and check overall design, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example confirm that the expected energy use meets targets (model output) for variable system efficiency (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.18.2. Weather data available for present climate conditions
At this advanced design stage a detailed analysis of system performance and building thermal response is essential for the fine tuning of the design. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. Extreme and average winter conditions should be used to examine the system performance and associated energy use.
The CIBSE Test Reference Years (TRY) are often used for building simulation. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.18.3. Weather data available for future climate conditions
At this advanced design stage the designer should make sure that the systems would be able to cope with future conditions and extreme events and that there is scope for their further development towards lower energy use and carbon emissions. A detailed analysis of system future performance is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. Extreme and average winter conditions should be used to examine the system performance and associated energy use.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.18.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.18.5. Input from members
3.19. Check part load performance
3.19.1. CIBSE guidance and tools
At this advanced design stage a review of the overall system design against targets and client requirements could concentrate on various aspects of the design intent such as achieving required performance, energy efficiency at part load and performance of controls. This task will concentrate on confirming that the system efficiency targets and system performance requirements are met at part load.
Often systems operate at high efficiency at peak load and low efficiency at part load. The load diversity analysis in task 3.13 could identify integrated solutions for heating for example covering base load, peak load and contingency load with a combination of LZC technologies and boiler units.
Computer based simulation tools, such as thermal models, could be used to check integrated system performance at variable heating load, based on hourly external data. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine heating load variation (model output) for variable solar gain (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.19.2. Weather data available for present climate conditions
The systems’ performance will be often directly associated with external conditions. It is important that the designer is able to check that the heating strategy will cover low and high demand without compromising its efficiency. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. Certain winter events (e.g. sunny and warm winter days, especially when solar systems are used) could be identified in order to examine the integrated system performance and associated energy use.
The CIBSE Test Reference Years (TRY) are often used for building simulation. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data of certain summer events, e.g. days of variable solar gains. Attached probability to the occurrence of certain winter events could assist in better understand the overall efficiency of the systems.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.19.3. Weather data available for future climate conditions
Conclusions on the variable load performance of the system based on future conditions could help identify the potential of reducing energy use for heating and hot water purposes. It is increasingly part of the client’s brief to present options for a future zero or neutral carbon building, so it is important that the designer is able to examine further options. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. The system variable load performance could be examined for certain future winter events (e.g. more sunny and warm winter days, especially when solar systems are used) in order to identify future options e.g. replace the conventional boiler with a solar system.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of x consecutive sunny days (max solar gains).
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.19.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.19.5. Input from members
3.20. Check that the selected controls are capable of achieving the required level of control, response and energy efficiency, particularly at part load
3.20.1. CIBSE guidance and tools
At this advanced design stage a review of the overall system design against targets and client requirements could concentrate on various aspects of the design intent such as achieving required performance, energy efficiency at part load and performance of controls. This task will concentrate on confirming that the controls are able to respond effectively to the changes in the internal environment without compromising energy efficiency.
Often systems operate at variable efficiency based on demand. The load diversity analysis in task 3.13 could identify integrated solutions for heating for example covering base load, peak load and contingency load with a combination of LZC technologies and boiler units. Integrated solutions will require the fine tuning of their controls to make sure that variable load is covered without compromising the systems’ efficiency.
Computer based simulation tools, such as thermal models, should be used to check performance of controls at variable load, based on hourly external data. Results from simulations completed during tasks 3.16-3.19 could also be used here to extract information for the analysis of controls’ performance. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
In relation to computer based tools further guidance could explore the input and output stages of the simulation process by providing directions on sensitivity analysis of model output, based on model input. For example examine energy use (model output) for variable occupancy and solar gains (model input). Suggested sensitivity analysis could vary based on building/space application and construction/fabric, e.g. different for lightweight and heavyweight buildings, naturally and mechanically ventilated etc.
3.20.2. Weather data available for present climate conditions
The ability of the controls to respond effectively to variable load is essential for the efficient operation of the system. It is important that the designer is able to check that the system will respond effectively to variable load without compromising its efficiency. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. Certain winter events (e.g. sunny and warm winter days, especially when solar systems are used) could be identified in order to examine the system performance and associated energy use.
The CIBSE Test Reference Years (TRY) are often used for building simulation. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data of certain summer events, e.g. days of variable solar gains. Attached probability to the occurrence of certain winter events could assist in better understand the overall efficiency of the systems.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.20.3. Weather data available for future climate conditions
Conclusions on the ability of the controls to respond effectively to variable load based on future conditions could help identify future requirements for the fine tuning of controls. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic performance of the building in response to external conditions. The response of the controls to the system’s variable performance could be examined for future summer events (e.g. more sunny and warm winter days will require fewer occasions of system operating at peak load) in order to identify future control requirements.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of x consecutive sunny days (max solar gains).
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.20.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.20.5. Input from members
3.21. Check that final system and components meet client requirements for performance, quality, reliability, etc at acceptable cost; and also meet required energy targets and comply with regulations, such as meeting the seasonal efficiency requirements
3.21.1. CIBSE guidance and tools
This task confirms that the final solution does meet original design objectives. Actions could include value engineering and confirming compliance with the building regulations. Building services engineers should also make sure that there are no major alterations in the building’s envelope that have been done by the design team to effect building performance.
Computer based simulation tools, such as thermal models, should be used to check overall building performance and compliance with the building regulations, based on hourly external data. Results from simulations completed during previous tasks could also be used here. CIBSE TM33 “Tests for Software Accreditation and Verification”, provides ways to check the validity of dynamic models. CIBSE AM11 “Building Energy and Environmental Modelling” provides comprehensive guidance on the use of computer models, including the various options available and associated uncertainty and risk.
CIBSE could provide guidance on how to complete a value engineering assessment and issues associated. Guidance on SBEM and the other accredited compliance tools could inform the designers of the ‘problem areas’ related to the use of each of the tools. Finally, checklists of possible areas where last minute changes e.g. by completing a value engineering assessment, could affect the building performance could be beneficial towards maintaining performance of design intent.
3.21.2. Weather data available for present climate conditions
Building Regulations require the use of certified computer tools in order to prove compliance. The above requirement is also part of the European Energy Performance of Buildings Directive. Such tools use hourly weather data to provide information on the energy use and associated carbon emissions of the building and as a result provide evidence of the building’s design intent compliance with the building regulations.
The CIBSE Test Reference Years (TRY) are often used for building energy performance assessments. These are hourly weather series over a year and for 14 different UK locations.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of winter events, e.g. once in x observed years event of low temperature and wind speed.
The currently available TRYs were specifically composed for the calculation of energy use in buildings over a year and express average conditions, while they exclude any extreme events. Furthermore, the TRYs are based on the 1983-2002 baseline, which almost certainly will not represent the external conditions through the lifetime of the building.
The use of probabilities in weather data used for simulations could help in better understand the risk associated with the design of the building and its services. The next generation of UKCIP climate change scenarios (UKCIP08) is expected to present past events based on observed data in a probabilistic way (http://www.ukcip08.net).
The next generation of UKCIP climate change scenarios (UKCIP08), produced by the Met Office’s Hadley Centre, is expected to include weather information based on observed data as well as climate change model output. A variety of weather information based on observed data will be freely available through the UKCIP08 user interface (http://www.ukcip08.net).
There are currently discussions that explore the ways to use future weather data rather than present data, based on past baselines, in building design. CIBSE’s Climate Task Force is examining the short and long term options of providing the industry with the best available weather information. Furthermore, a group of EPSRC funded projects are examining the use of climate change information in building design.
3.21.3. Weather data available for future climate conditions
Even though not formally required by the Building Regulations it is increasingly the client’s brief requirement to show that the building will be able to maintain predicted energy performance over its lifetime. This is possible by the use of computer based tools that use hourly weather series to provide a dynamic energy performance of the building in response to external conditions. Such tools use hourly weather data to provide information on the energy use and associated carbon emissions of the building and as a result provide evidence of the building’s long term energy performance based on design intent.
CIBSE in collaboration with UK Climate Impacts Programme (UKCIP) and ARUP has produced future hourly weather years, based on the existing Design Summer Years (DSYs) and Test Reference Years (TRYs), which incorporate the UKCIP02 climate change scenarios. The above future weather years are available for the same 14 sites, for three timeslices (‘2020s’ 2011-2040, ‘2040s’ 2041-2070 and ‘2080s’ 2071-2100) and for four emissions scenarios (Low, Medium-Low, Medium- High and High) (the future weather years could be ordered from http://www.cibse.org/index.cfm?go=page.view&item=1300). The data may also be provided ready-formatted for certain simulation packages (contact Ken Butcher on 020 8772 3628 or email kbutcher@cibse.org for details). Purchasers of any of the above packages will also receive CIBSE’s TM48: “Climate Change Data for Building Simulation”. TM48 serves as a valuable companion to the future DSYs and TRYs with information and guidance on their production and use.
CCWeatherGen – A Climate Change Weather File Generator: A climate change weather file generator (CCWeatherGen) has been developed by the Sustainable Urban Environment (SUE) programme at the School of Civil Engineering and the Environment, University of Southampton. The tool is Microsoft® Excel-based and uses the UKCIP02 climate change scenarios to transform CIBSE / Met Office TRY/DSY weather files into climate change TMY2 or EPW weather files which are compatible with the majority of building performance simulation programs. The CCWeatherGen and the accompanying documentation are available without charge from http://www.energy.soton.ac.uk/ccweathergen. This tool can be used to generate morphed versions of the DSY and TRY files similar to those provided by CIBSE. However, use of this tool does require some specialist expertise. Consequently, CIBSE is not responsible for any errors associated with its use or any other software to reproduce the morphed files provided by CIBSE. The objective of providing the ready made files is to provide a standardised data set for the industry providing a common platform for climate change impact assessments.
All current climate change data in CIBSE guidance originate from the Met Office’s Hadley Centre model outputs. Four UKCIP02 climate change scenarios are presented at a 50km x 50km resolution based on outputs from the Hadley Centre’s global and regional climate models (Had CM3 and HadRM3, respectively). For each of the four UKCIP02 climate change scenarios (H, M-H, M-L, L), changes are described for three future thirty-year time-slices: 2011 to 2040 (the 2020s), 2041 to 2070 (the 2050s) and 2071 to 2100 (the 2080s). All changes in climate are given relative to the baseline period of 1961 to 1990. For more information on emissions scenarios and the products freely available look at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=161&Itemid=291.
The next generation of climate change information (UKCP09) is currently available and presented in a probabilistic way ( http://ukclimateprojections.defra.gov.uk/). The UKCP09 provide information in various formats such as maps, graphs, plots, etc, available in printed reports and in customisable outputs. Changes in weather variables such as temperatures, rainfall, cloud cover etc are presented in a probabilistic way and are available for 25km grid squares, three emissions scenarios (Low, Medium and High) and seven future overlapping 30 year time periods. The provision of probabilistic projections is the major change from the previous UKCIP02 projections. Probabilistic projections assign a probability to different possible climate change outcomes, recognising the uncertainty involved in their production and inherent of our global climate, and as such help with making more robust adaptation decisions. A User Interface portal ((http://ukclimateprojections.defra.gov.uk) has been specifically designed to guide the user to the information more appropriate to them and to explain the underlying science and outputs along the way. One of the resources provided through the User Interface is a Weather Generator which is a type of statistical model that uses relationships between climate variables to generate daily and hourly time series. The produced time series are comprised of set of climate variables at a 5 km resolution that are consistent with the underlying 25 km resolution climate projections. Customisable outputs, including the Weather Generator, are accessible after registration.
For the dynamic computer simulations the user should be looking for hourly data with attached probability of occurrence of future winter events, e.g. probability of certain coincidence of low temperature and wind speed happening in the next x years.
All currently available climate change data and weather series are presented in a deterministic way which means that a single number is used to express future changes in weather variables. A good understanding of the uncertainty related to the development of climate change data is essential in order to assist in robust design decisions. Information on the uncertainty associated with climate change information could be found at http://www.ukcip.org.uk/index.php?option=com_content&task=view&id=232&Itemid=326. The next generation of UKCIP scenarios is expected to present changes in a probabilistic way (http://www.ukcip08.net).
Although the new climate projections UKCP09 offer an opportunity for the building professionals to better understand and apply climate change information in the future proofing of buildings, their complexity and existing format can hinder their immediate implementation in building design. One of the issues associated with the data is the lack of correlation between weather variables presented as maps and graphs (Cumulative Distribution Function – CDF and Probability Density Function – PDF). For example for overheating calculations there is no correlation between the temperature and solar radiation figures for a given probability. Other issues include the weakness of the Weather Generator to represent extreme events, as well as the lack of projections on wind speed and direction.
The climate change trends (in both UKCIP and CIBSE guidance) are based on a different baseline (1961-1990) than the present day statistics (Guide A 1983-2002, Guide J 1976-1995, TRYs and DSYs 1983-2004) and so they are not directly comparable.
A group of EPSRC funded projects “Adaptation and Resilience in a Changing Climate” – ARCC are examining the use of probabilistic data and climate change information in building design. CIBSE is representing its members as a key stakeholder, technically co-ordinating the outputs of the projects. For more information and to get involved visit: http://www.ukcip-arcc.org.uk/
The outcomes from the above EPSRC funded projects will be integrated into the “Design Compass” as they emerge.
CIBSE’s suggestion of suitable external design conditions based on climate change data for use towards future proofing of buildings and their services should be made available and be incorporated in the weather related CIBSE guidance. Furthermore, CIBSE could further develop guidance on possible design options for adapting buildings to climate change, for both new built and refurbishments.
3.21.4. Other useful references
South East Climate Change Partnership “Adapting to Climate Change: a checklist for Developers”, November 2005
European Climate Assessment & Dataset (ECA&D) project for indices of extremes and daily information based on observations, for various European locations including UK: http://eca.knmi.nl/
The British Wind Energy Association gives access to wind speeds in the UK: http://www.bwea.com/
3.21.5. Input from members
4. Pre-Construction
F. Production information
G. Tender documentation
H. Tender action
4.1. Information from Design Development stage to be used here
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4.2. CIBSE members’ involvement at this stage depends on the individual contract with the client
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5. Construction
J. Mobilisation
K. Construction to practical completion
5.1. CIBSE members’ involvement at this stage depends on the individual contract with the client
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6. Post completion
L. Post practical completion
6.1. Commissioning, management and maintenance of the heating system
6.1.1. CIBSE guidance and tools
Guidance on the commissioning, management and maintenance of the building services, after the completion of the project, could be used here by facilities and energy managers in order to meet the design specifications.
The CIBSE Commissioning Codes such as Code B “Boilers”, Code C “Automatic Controls” and KS09 Commissioning Variable Flow Pipework Systems” could be used here to inform the commissioning process of the heating system. CIBSE Guide M “Maintenance Engineering and Management” provide guidance on the management and maintenance of the building services.
CIBSE guidance seems sufficient.
6.1.2. Other useful references
6.1.3. Input from members
6.2. Design review – Refer to feedback and lessons learned
6.2.1. CIBSE guidance and tools
The building services engineers should be able to keep in touch with previous projects in order to learn from them and improve their design methods.
For post occupancy reviews see energy audits and surveys in Guide F “Energy Efficiency in Buildings”, chapter 18.
CIBSE could offer guidance on reviews at design stage (project team meetings, reviews with other design teams etc) and reviewing system performance at post occupancy.
Further guidance could include advice on possible channels and actions through which the design team could revisit or keep in touch with previous projects. Perhaps some research could be done in current practices.
Could CIBSE influence client perception of the value of monitoring and feedback? In some current projects monitoring and feedback is used as educational process.
Encourage integration with Facilities Management (FM), e.g. develop processes of reporting to the design team.
6.2.2. Other useful references
6.2.3. Input from members
6.3. End of life
6.3.1. CIBSE guidance and tools
Guidance on the building demolition and the recycling of materials is relevant here.
CIBSE Guide L “Sustainability”, chapter 8, provides some guidance on this last stage of the building’s life.
Further guidance is needed on end of life stage.
6.3.2. Other useful references
6.3.3. Input from members