1、BS EN ISO6946:2007ICS 91.060.01; 91.120.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDBuilding componentsand buildingelements Thermalresistance and thermaltransmittance Calculation method(ISO 6946:2007)Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 1
2、2/01/2009 02:50, Uncontrolled Copy, (c) BSIThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 32008 BSI 2008ISBN 978 0 580 54937 3Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 6946:2007National forewordThis British Standard is
3、 the UK implementation of EN ISO 6946:2007. Itsupersedes BS EN ISO 6946:1997 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee B/540, Energy performance of materials components andbuildings.A list of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 be obta
4、ined onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.0 SeptemberLicensed Copy: Wang Bin, ISO/EXCHANGE C
5、HINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 6946December 2007ICS 91.060.01; 91.120.10 Supersedes EN ISO 6946:1996 English VersionBuilding components and building elements - Thermalresistance and thermal transmittance - Calculation
6、 method (ISO6946:2007)Composants et parois de btiments - Rsistance thermiqueet coefficient de transmission thermique - Mthode decalcul (ISO 6946:2007)Bauteile - Wrmedurchlasswiderstand undWrmedurchgangskoeffizient - Berechnungsverfahren (ISO6946:2007)This European Standard was approved by CEN on 7 D
7、ecember 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be ob
8、tained on application to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Manage
9、ment Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
10、 Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by
11、 any means reservedworldwide for CEN national Members.Ref. No. EN ISO 6946:2007: ELicensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIBS EN ISO 6946:2007EN ISO 6946:2007 (E) 3 Foreword This document (EN ISO 6946:2007) has been prepared by Technical Comm
12、ittee ISO/TC 163 “Thermal performance and energy use in the built environment“ in collaboration 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 stand
13、ard, either by publication of an identical text or by endorsement, at the latest by June 2008, and conflicting national standards shall be withdrawn at the latest by June 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN a
14、nd/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 6946:1996. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Aust
15、ria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorseme
16、nt notice The text of ISO 6946:2007 has been approved by CEN as a EN ISO 6946:2007 without any modification. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIBS EN ISO 6946:2007ISO 6946:2007(E) ISO 2007 All rights reserved iiiContents Page Foreword i
17、v Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms, definitions, symbols and units . 1 3.1 Terms and definitions. 1 3.2 Symbols and units 2 4 Principles. 2 5 Thermal resistances . 3 5.1 Thermal resistance of homogeneous layers . 3 5.2 Surface resistances 3 5.3 Thermal resistance of air
18、layers 4 5.4 Thermal resistance of unheated spaces 6 6 Total thermal resistance 7 6.1 Total thermal resistance of a building component consisting of homogeneous layers. 7 6.2 Total thermal resistance of a building component consisting of homogeneous and inhomogeneous layers. 7 7 Thermal transmittanc
19、e . 11 Annex A (normative) Surface resistance. 12 Annex B (normative) Thermal resistance of airspaces 15 Annex C (normative) Calculation of the thermal transmittance of components with tapered layers . 18 Annex D (normative) Corrections to thermal transmittance 22 Bibliography . 28 Licensed Copy: Wa
20、ng Bin, ISO/EXCHANGE CHINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIBS EN ISO 6946:2007ISO 6946:2007(E) iv ISO 2007 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work
21、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. International organizations, governmental and non-government
22、al, 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 given in the ISO/IEC Directives, Part 2. The mai
23、n 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 75 % of the member bodies casting a vote. Att
24、ention 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 6946 was prepared by Technical Committee ISO/TC 163, Thermal performance and energy use in the built
25、 environment, Subcommittee SC 2, Calculation methods. This second edition cancels and replaces the first edition (ISO 6946:1996), which has been technically revised. It also incorporates the Amendment ISO 6946:1996/Amd.1:2003. The following changes have been made to the first edition: information on
26、 the calculation of heat flow rates has been transferred from the Introduction to the note in Clause 4; 5.3.3 provides an amended basis for slightly ventilated air layers; 5.4.2 provides clarification of the applicability of Table 3; 5.4.3 has been completely revised; 6.2.1 provides a new text to al
27、low calculation of a component that is part of a complete element; it also clarifies exceptions and the limit of applicability; Annex B provides additional data for other temperature differences across cavities; it also provides a correction to the formula for radiation transfer in divided airspaces
28、; Annex C contains an additional shape; D.2 has been completely rewritten to clarify the intentions, the former Annex E having been deleted (national annexes can be attached to this International Standard giving examples in accordance with local building traditions); D.3 provides a revised procedure
29、 for mechanical fasteners, including recessed fasteners; D.4 does not apply in cooling situations. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIBS EN ISO 6946:2007ISO 6946:2007(E) ISO 2007 All rights reserved vIntroduction This International Stan
30、dard provides the means (in part) to assess the contribution that building products and services make to energy conservation and to the overall energy performance of buildings. Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIBS EN ISO 6946:2007Licen
31、sed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIBS EN ISO 6946:2007INTERNATIONAL STANDARD ISO 6946:2007(E) ISO 2007 All rights reserved 1Building components and building elements Thermal resistance and thermal transmittance Calculation method 1 Scope Thi
32、s International Standard provides the method of calculation of the thermal resistance and thermal transmittance of building components and building elements, excluding doors, windows and other glazed units, curtain walling, components which involve heat transfer to the ground, and components through
33、 which air is designed to permeate. The calculation method is based on the appropriate design thermal conductivities or design thermal resistances of the materials and products for the application concerned. The method applies to components and elements consisting of thermally homogeneous layers (wh
34、ich can include air layers). This International Standard also provides an approximate method that can be used for elements containing inhomogeneous layers, including the effect of metal fasteners, by means of a correction term given in Annex D. Other cases where insulation is bridged by metal are ou
35、tside the scope of this International Standard. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any
36、 amendments) applies. ISO 7345, Thermal insulation Physical quantities and definitions ISO 10456, Building materials and products Hygrothermal properties Tabulated design values and procedures for determining declared and design thermal values ISO 13789, Thermal performance of buildings Transmission
37、 and ventilation heat transfer coefficients Calculation method 3 Terms, definitions, symbols and units 3.1 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 7345 and ISO 10456 and the following apply. 3.1.1 building element major part of a building such
38、as a wall, floor or roof Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIBS EN ISO 6946:2007ISO 6946:2007(E) 2 ISO 2007 All rights reserved3.1.2 building component building element or a part of it NOTE In this International Standard, the word “compo
39、nent” is used to indicate both element and component. 3.1.3 thermally homogeneous layer layer of constant thickness having thermal properties which may be regarded as being uniform 3.2 Symbols and units Symbol Quantity Unit A area m2d thickness m h surface heat transfer coefficient W/(m2K) R design
40、thermal resistance (surface to surface) m2K/W Rgthermal resistance of airspace m2K/W Rseexternal surface resistance m2K/W Rsiinternal surface resistance m2K/W RTtotal thermal resistance (environment to environment) m2K/W TR upper limit of total thermal resistance m2K/W TR lower limit of total therma
41、l resistance m2K/W Ruthermal resistance of unheated space m2K/W U thermal transmittance W/(m2K) design thermal conductivity W/(mK) 4 Principles The principle of the calculation method is as follows: to obtain the thermal resistance of each thermally homogeneous part of the component; to combine thes
42、e individual resistances so as to obtain the total thermal resistance of the component, including (where appropriate) the effect of surface resistances. Thermal resistances of individual parts are obtained in accordance with 5.1. The values of surface resistance given in 5.2 are appropriate in most
43、cases. Annex A gives detailed procedures for low emissivity surfaces, specific external wind speeds and non-planar surfaces. Air layers may be regarded as thermally homogeneous for the purposes of this International Standard. Values of the thermal resistance of large air layers with high emissivity
44、surfaces are given in 5.3. Annex B provides procedures for other cases. The resistances of the layers are combined as follows: a) for components consisting of thermally homogeneous layers, obtain the total thermal resistance in accordance with 6.1 and the thermal transmittance in accordance with Cla
45、use 7; Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 12/01/2009 02:50, Uncontrolled Copy, (c) BSIBS EN ISO 6946:2007ISO 6946:2007(E) ISO 2007 All rights reserved 3b) for components having one or more thermally inhomogeneous layers, obtain the total thermal resistance in accordance with 6.2
46、and the thermal transmittance in accordance with Clause 7; c) for components containing a tapered layer, obtain the thermal transmittance and/or the total thermal resistance in accordance with Annex C. Finally, corrections are applied to the thermal transmittance, if appropriate, in accordance with
47、Annex D, in order to allow for the effects of air voids in insulation, mechanical fasteners penetrating an insulation layer and precipitation on inverted roofs. The thermal transmittance calculated in this way applies between the environments on either side of the component concerned, e.g. internal
48、and external environments, two internal environments in the case of an internal partition, an internal environment and an unheated space. Simplified procedures are given in 5.4 for treating an unheated space as a thermal resistance. NOTE Calculation of heat flow rates are commonly undertaken using o
49、perative temperature (usually approximated to the arithmetic mean of air temperature and mean radiant temperature) to represent the environment inside buildings, and air temperature to represent the external environment. Other definitions of the temperature of an environment are also used when appropriate to the purpose of the calculation. See also Annex A. 5 Thermal resistances 5.1 Thermal resistance of homogeneous layers Design thermal values can be given as either design thermal conductivity o
