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1、Climate change and the indoor environment: impacts and adaptation CIBSE TM36: 2005 The Chartered Institution of Building Services Engineers 222 Balham High Road, London SW12 9BS The rights of publication or translation are reserved. No part of this publication may be reproduced, stored in a retrieva
2、l system or transmitted in any form or by any means without the prior permission of the Institution. February 2005 The Chartered Institution of Building Services Engineers London Registered charity number 278104 ISBN 1 903287 50 2 This document is based on the best knowledge available at the time of
3、 publication. However no responsibility of any kind for any injury, death, loss, damage or delay however caused resulting from the use of these recommendations can be accepted by the Chartered Institution of Building Services Engineers, the authors or others involved in its publication. In adopting
4、these recommendations for use each adopter by doing so agrees to accept full responsibility for any personal injury, death, loss, damage or delay arising out of or in connection with their use by or on behalf of such adopter irrespective of the cause or reason therefore and agrees to defend, indemni
5、fy and hold harmless the Chartered Institution of Building Services Engineers, the authors and others involved in their publication from any and all liability arising out of or in connection with such use as aforesaid and irrespective of any negligence on the part of those indemnified. Layout and ty
6、pesetting by CIBSE Publications Printed in Great Britain by Page Bros. (Norwich) Ltd., Norwich, Norfolk NR6 6SA Cover illustration: Winter Garden at Canary Wharfe East (artists impression). Reproduced by courtesy of Cesar Pelli consid- eration of climate change issues is therefore necessary now to e
7、nsure the longevity of the building stock. Not to do so will result in a generation of buildings that are likely to become obsolete within their useful lifetime, or require costly and difficult retrofits. Designing for the anticipated future climate is therefore very much a current issue. Until now,
8、 however, there has been little information available regarding the magnitude of these effects. While mechanical air conditioning is an obvious tech- nological solution to adapt to the warming climate, this route is undesirable for two reasons. First, inclusion, retrofitting and maintenance of air c
9、onditioning in many buildings is likely to be beyond the bounds of economic viability. This is particularly important in the domestic sector in which the very young, old or physically infirm are likely to suffer greatest harm from thermal discomfort and heat stress. Secondly, and perhaps more fundam
10、en- tally, use of air conditioning has the potential to increase significantly the energy burden of, and consequently the greenhouse gas emissions from, a building, thereby exacerbating the problem for which the adaptation is needed. It is estimated that buildings account for approximately 45% of to
11、tal energy consumption in the UK(1)and 41% across the European Community(2). There is, therefore, considerable potential to reduce emissions through good practice in building design and methods of use, e.g. by up to 50% for new buildings and following major refurbish- ment(2). This publication aims
12、to address these issues by providing guidance on measures to ensure summertime thermal comfort in UK buildings without incurring excessive energy use. There are a number of key questions: To what extent will climate change increase the occurrence of summertime thermal discomfort and overheating? To
13、what extent will passive measures be able to improve summertime thermal comfort and amelio- rate the increased propensity for overheating? How effective will different approaches to comfort cooling be under the changing climate? What are the energy use implications of the various strategies? These q
14、uestions are addressed here by quantitative assess- ment of the effect of climate change on building and HVAC system performance, measured by the frequency of overheating, energy consumption and carbon emissions. The risks posed by climate change to these performance measures are assessed in two way
15、s. First, properties of the future climate are examined to provide an initial, qualita- tive, assessment. Secondly, dynamic thermal modelling is used to make quantitative assessments of case study buildings drawn from three generic building types: dwellings, offices, and schools. The case study buil
16、dings are chosen to illustrate the response of different HVAC strategies, including manually operated natural ventila- tion, full mechanical air conditioning, and passive and low energy methods. An important aspect of the study was to analyse the performance of design features that successfully cool
17、 buildings without mechanical means, e.g. the control of solar radiation and ventilation, or the use of thermal storage. A number of approaches currently used in the UK and other parts of the world were applied to the case study buildings and tested under present and future climates. Novel technique
18、s such as embodying phase change materials within the building fabric were not considered, because the objective was to examine what can be done with existing technology. Similarly it was assumed that there will not be significant changes in modes of building use, including internal heat gains and o
19、ccupation patterns, over the time periods considered. Following this introduction, the structure of the docu- ment is as follows: Section 2: describes the climate change scenarios used and the method used to produce design weather years for projected future climates. Section 3: discusses design targ
20、ets for thermal performance and energy use. Section 4: describes some of the general impli- cations of the climate changes on the performance of different types of building based on the charac- teristics of the future weather years. Section 5: forms the core of the document and presents the results
21、of the dynamic thermal modelling of the case study buildings. Climate change and the indoor environment: impacts and adaptation 4Climate change and the indoor environment: impacts and adaptation Section 6: considers further strategies and remedial options for those buildings where limitations to per
22、formance have been identified. Section 7: presents the conclusions. Annex: contains the data sheets for the case study buildings and the results of thermal modelling. 2The climate scenarios 2.1UKCIP02 scenarios In 1998 the United Kingdom Climate Impacts Programme (UKCIP) released the first set of co
23、mprehensive climate change scenarios for the United Kingdom. This was done in recognition of the need to make quantitative assess- ments of the possible impacts of climate change. These scenarios were subsequently updated in 2002 as the UKCIP02 scenarios(3). (A further update is expected in 2007/8.)
24、 The principal changes in the 2002 scenarios are that (a) they make use of the more recent Met Office global climate model (HadCM3) and (b) they contain information from a regional model (HadRM3) embedded within the global climate model with a resolution of 50 km. The scenarios are being widely used
25、 to assess the possible impacts of climate change on the UK (see www.ukcip.org). It is likely that the scenarios will be further refined and developed in the future, but at present they represent the best available information on the likely course of climate change in the UK over the 21st century. S
26、ome types of climate scenario are excluded, e.g. sudden or gradual cooling of the northern hemisphere due to changes in the Gulf Stream. However, these types of climate change are considered to be of very low probability within the next 100 years and lie outside the range of scenarios presently bein
27、g considered in climate change impacts adaptation and planning. The following is a brief outline of how the scenarios were produced; full details are available in Hulme et al.(3) 2.1.1Emissions scenarios The basis for the UKCIP02 climate scenarios is a set of four storylines for greenhouse gas emiss
28、ions, which are taken from the Intergovernmental Panel on Climate Change (IPCC) SRES emissions scenarios. Each storyline represents a possible future, as described in Table 2.1, ranging from one relatively intensive in fossil fuel use and greenhouse gases emissions, to one in which sustainability is
29、 given high priority on a global level and fossil fuel use decreases. Figure 2.1 shows the predicted changes in atmospheric carbon dioxide over the coming century under each of the scenarios. These changes in atmospheric composition are computed independently of the climate models. They form the inp
30、ut forcing to the climate models, which then aim to calculate the resulting future climates . Note that even under the Low Emissions (Global Sustainability) scenario, atmospheric carbon dioxide continues to increase until around the middle of the century due to the projected timescale to phase out f
31、ossil fuel use. In the scenarios it is therefore anticipated that there will be an appreciable level of climate change over the course of the century even if substantial efforts are made now to reduce greenhouse gas emissions. 2.1.2The global climate model Predictions for global temperature change i
32、n UKCIP02 were obtained in the following way. First, the global climate model was run for the period from 1860 (a nominal pre-industrial starting point) until 1990 using observed changes in greenhouse gases and other natural forcings of climate change such as volcanoes. The data for the thirty-year
33、period 19601990 were averaged to form the baseline climate. Next, the global climate model was run forward until 2100 for each of the four emissions scenarios. Values of global average temperature in the runs are shown in Figure 2.2. Finally, these data were averaged over three 30-year timeslices: t
34、he 2020s, 2050s and 2080s Table 2.1 Characteristics of the UKCIP emissions scenarios (from tables A.2 and A.3 of the UKCIP02 report(3) UKCIP02 climate change IPCC SRESUKCIP socio-economic Description scenarioemissions storylinescenario title Low EmissionsB1Global SustainabilityClean and efficient te
35、chnologies; reduction in material use; global solutions to economic, social and environmental sustainability; improved equity; population peaks mid- century Medium-Low EmissionsB2Local StewardshipLocal solutions to sustainability; continuously increasing population Medium-High EmissionsA2National En
36、terpriseSelf-reliance; preservation of local identities; continuously increasing population; economic growth on regional scales High EmissionsA1F1World MarketsVery rapid economic growth; population peaks mid- century; social, cultural and economic convergence among regions; market mechanisms dominat
37、e. 1960198020002020204020802060 A1F1 A2 B2 B1 2100 1000 900 800 700 600 500 400 300 200 1000 900 800 700 600 500 400 300 200 Carbon dioxide concentration / ppm Figure 2.1 Global carbon dioxide increases (reproduced from UKCIP02 Scientific Report(1); Crown copyright) The climate scenarios5 correspond
38、ing to the periods 20112040, 20412070 and 20712100, respectively. The four emissions scenarios and three timeslices in UKCIP02 make a total of twelve climate examples to consider. Dealing with the complete set of scenarios is therefore a considerable undertaking. However, the scenarios are mathemati
39、cally linked and the differences between them are proportional. The proportionality is given by a climate scaling factor (CSF), which is defined as the ratio of the global average temperature change in a scenario relative to that in the Medium-High 2080s scenario (the CSFis called the pattern scalin
40、g factor in UKCIP02). The scenarios are listed in Table 2.2 in order of increasing average global temperature change and CSF. The CSFvalues in this table may be used to relate the climate changes under a given scenario to those in the Medium-High Emissions 2080s scenario which has a CSFof 1.0. A gra
41、phical comparison of CSFs is shown in Figure 2.3. It can be seen that in the 2020s the level of climate change in the four emissions scenarios is similar, which is because the levels of CO2in the atmosphere are similar at this time (Figure 2.1). By the 2050s timeslice, however, the four scenarios ar
42、e starting to diverge, with differences being quite appreciable by the 2080s timeslice. For example in the 2080s the climate scaling factor associated with the High Emissions scenario is around twice that of the Low Emissions scenario. Figure 2.3 also indicates that the climate scaling factor of dif
43、ferent scenarios is similar at different timeslices. For example, the level or warming in the Low Emissions scenarios 2080s is similar to that in the Medium-High scenario 2050s, and that in the Medium- Low scenario 2080s similar to that in the High scenario 2050s. 2.1.3The regional climate model The
44、 size of the computational grid boxes for the global climate model (HadCM3) is approximately 300 km over the UK. This spatial resolution is too coarse to resolve the geographical variations due to factors such as topography and coastline morphology. To produce such information, a regional climate mo
45、del (HadRM3), covering only the UK and part of northern Europe was used. The regional model takes boundary conditions from the global climate model and the size of the computational grid boxes was approximately 50 km. Running the regional climate model is computationally intensive, requiring several
46、 months of super-computer power. For this reason only a limited number of model runs were made. All the regional detail in the UKCIP02 scenarios is based on regional model runs for the Medium-High Emissions scenario 2080s and the baseline 19611990 climate. Results for the present day climate were th
47、en subtracted from the 2080s results, giving the change in the climate parameters across the UK on a 50 km grid. The philosophy adopted in UKCIP02 is that the geographical variations in climate changes across the UK are the same for all scenarios but vary in magnitude in direct propor- tion to the g
48、lobal average temperature change. To obtain regional climate changes for the other scenarios and timeslices, the changes for the Medium-High Emissions scenarios are simply multiplied by the CSFvalues given in Table 2.2. This method is called pattern scaling. The resulting UKCIP02 climate scenarios c
49、ontain monthly averaged values of climate variables recorded on the 50 km computational grid. The variables available are: temperature (daily average, maximum and mini- mum dry-bulb) total precipitation snowfall rate 10 m wind speed relative and specific humidity total cloud in the longwave radiation band net surface long and shortwave radiation total downward shortwave radiation soil moisture content mean sea-level pressure surface latent heat flux. 185019001950 Observations 200020502100 6 4 2 0 -2 Temperature change / K A2 A1F1 B2 B1 Figure 2
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