BS EN ISO 13788-2012 Hygrothermal performance of building components and building elements Internal surface temperature to avoid critical surface humidity and interstitial condensa.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 13788:2012Hygrothermal performanceof building components andbuilding elements Internalsurface temperature to avoidcritical surface humidity andinterstitial condensation

2、 Calculation methods (ISO13788:2012)Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 13788:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implemen

3、tation of EN ISO13788:2012. It supersedes BS EN ISO 13788:2002 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee B/540, Energy performance of materials components andbuildings.A list of organizations represented on this committee can beobtained on request

4、 to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 72096 3ICS 91.060.01; 91.120.10Compliance with a Br

5、itish Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 January 2013.Amendments issued since publicationDate Text affectedCopyright European Committee for Standardization Provided by IHS u

6、nder license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 13788 December 2012 ICS 91.060.01; 91.120.10 Supersedes EN ISO 13788:2001English Version Hygrothermal performance of building components an

7、d building elements - Internal surface temperature to avoid critical surface humidity and interstitial condensation - Calculation methods (ISO 13788:2012) Performance hygrothermique des composants et parois de btiments - Temprature superficielle intrieure permettant dviter lhumidit superficielle cri

8、tique et la condensation dans la masse - Mthodes de calcul (ISO 13788:2012) Wrme- und feuchtetechnisches Verhalten von Bauteilen und Bauelementen - Raumseitige Oberflchentemperatur zur Vermeidung kritischer Oberflchenfeuchte und Tauwasserbildung im Bauteilinneren - Berechnungsverfahren (ISO 13788:20

9、12) This European Standard was approved by CEN on 28 December 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographica

10、l references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility o

11、f a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Ma

12、cedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION E

13、UROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 13788:2012: ECopyright European Committee for Standardization Provided by IHS under license

14、 with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 13788:2012EN ISO 13788:2012 (E) 3 Foreword This document (EN ISO 13788:2012) has been prepared by Technical Committee ISO/TC 163 “Thermal performance and energy use in the built environment“ in coll

15、aboration with Technical Committee CEN/TC 89 “Thermal performance of buildings and building components” the secretariat of which is held by SIS. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by Jun

16、e 2013, and conflicting national standards shall be withdrawn at the latest by June 2013. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent righ

17、ts. This document supersedes EN ISO 13788:2001. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Fo

18、rmer Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 1378

19、8:2012 has been approved by CEN as a EN ISO 13788:2012 without any modification. Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 13788:2012ISO 13788:2012(E) ISO 2012 Al

20、l rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions, symbols and units . 13.1 Terms and definitions . 13.2 Symbols and units 33.3 Subscripts 44 Input data for the calculations . 44.1 Material and product properties . 44.2 External bou

21、ndary conditions . 44.3 Internal boundary conditions 64.4 Surface resistances 65 Calculation of surface temperature to avoid critical surface humidity . 75.1 General . 75.2 Determining parameters 75.3 Design for avoidance of mould growth, corrosion or other moisture damage 75.4 Design for the limita

22、tion of surface condensation on low thermal inertia elements 86 Calculation of interstitial condensation . 96.1 General . 96.2 Principle 96.3 Limitation of sources of error . 106.4 Calculation . 106.5 Criteria used to assess building components 167 Calculation of drying of building components .167.1

23、 General 167.2 Principle . 177.3 Specification of the method 177.4 Criteria used to assess drying potential of building components 17Annex A (informative) Internal boundary conditions .18Annex B (informative) Examples of calculation of the temperature factor at the internal surface to avoid critical

24、 surface humidity .20Annex C (informative) Examples of calculation of interstitial condensation 24Annex D (informative) Example of the calculation of the drying of a wetted layer .34Annex E (informative) Relationships governing moisture transfer and water vapour pressure .37Bibliography .40Copyright

25、 European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 13788:2012ISO 13788:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national

26、 standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Internationa

27、l organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules g

28、iven in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least

29、 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 13788 was prepared by Technical Committee ISO/TC 163, Th

30、ermal performance and energy use in the built environment, Subcommittee SC 2, Calculation methods in cooperation with CEN/TC 89, Thermal performance of buildings and building components.This second edition cancels and replaces the first edition (ISO 13788:2001), which has been technically revised.iv

31、 ISO 2012 All rights reservedCopyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 13788:2012ISO 13788:2012(E)IntroductionMoisture transfer is a very complex process and the

32、knowledge of moisture transfer mechanisms, material properties, initial conditions and boundary conditions is often limited. Therefore this International Standard lays down simplified calculation methods, which assume that moisture transport is by vapour diffusion alone and use monthly climate data.

33、 The standardization of these calculation methods does not exclude use of more advanced methods. If other sources of moisture, such as rain penetration or convection, are negligible, the calculations will normally lead to designs well on the safe side and if a construction fails a specified design c

34、riterion according to this procedure, more accurate methods may be used to show that the design will pass.This International Standard deals with:a) the critical surface humidity likely to lead to problems such as mould growth on the internal surfaces of buildings,b) interstitial condensation within

35、a building component, in: heating periods, where the internal temperature is usually higher than outside; cooling periods, where the internal temperature is usually lower than the outside; cold stores, where the internal temperature is always lower than outside.c) an estimate of the time taken for a

36、 component, between high vapour resistance layers, to dry, after wetting from any source, and the risk of interstitial condensation occurring elsewhere in the component during the drying process.This International Standard does not cover other aspects of moisture, e.g. ground water and ingress of pr

37、ecipitation.In some cases, airflow from the interior of the building into the structure is the major mechanism for moisture transport, which can increase the risk of condensation problems very significantly. This International Standard does not address this issue; where it is felt to be important, m

38、ore advanced assessment methods should be considered.The limitations on the physical processes covered by this International Standard mean that it can provide a more robust analysis of some structures than others. The results will be more reliable for lightweight, airtight structures that do not con

39、tain materials that store large amounts of water. They will be less reliable for structures with large thermal and moisture capacity and which are subject to significant air leakage. ISO 2012 All rights reserved vCopyright European Committee for Standardization Provided by IHS under license with CEN

40、Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 13788:2012Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 13788:2012Hygroth

41、ermal performance of building components and building elements Internal surface temperature to avoid critical surface humidity and interstitial condensation Calculation methods1 ScopeThis International Standard gives simplified calculation methods for:a) The internal surface temperature of a buildin

42、g component or building element below which mould growth is likely, given the internal temperature and relative humidity. The method can also be used to assess the risk of other internal surface condensation problems.b) The assessment of the risk of interstitial condensation due to water vapour diff

43、usion. The method used does not take account of a number of important physical phenomena including: the variation of material properties with moisture content; capillary suction and liquid moisture transfer within materials; air movement from within the building into the component through gaps or wi

44、thin air spaces; the hygroscopic moisture capacity of materials.Consequently, the method is applicable only where the effects of these phenomena can be considered to be negligible.c) The time taken for water, from any source, in a layer between two high vapour resistance layers to dry out and the ri

45、sk of interstitial condensation occurring elsewhere in the component during the drying process.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edi

46、tion of the referenced document (including any amendments) applies.ISO 6946:2007, Building components and building elements Thermal resistance and thermal transmittance Calculation methodISO 9346, Hygrothermal performance of buildings and building materials Physical quantities for mass transfer Voca

47、bularyISO 15927-1, Hygrothermal performance of buildings Calculation and presentation of climatic data Part 1: Monthly means of single meteorological elements3 Terms and definitions, symbols and units3.1 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 9

48、346 and the following apply.INTERNATIONAL STANDARD ISO 13788:2012(E) ISO 2012 All rights reserved 1Copyright European Committee for Standardization Provided by IHS under license with CENNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-BS EN ISO 13788:2012ISO 13788:2012(E)3.1.1monthly mean temperaturemean temperature calculated from hourly values or the daily maximum and minimum temperature over a month3.1.2temperature factor at the internal surfacedifference between the temperature of the internal surface and the external air temperatur