1、BSI Standards PublicationBS EN ISO 15758:2014Hygrothermal performanceof building equipmentand industrial installations Calculation of watervapour diffusion Cold pipeinsulation systemsBS EN ISO 15758:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO15758:2
2、014. It supersedes BS EN 14114:2002 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee B/540, Energy performance of materials components andbuildings.A list of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 to its secretary.This publ
3、ication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 74686 4ICS 91.120.10; 91.140.01Compliance with a British Standard cannot confe
4、r immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 May 2014.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 15758 May 2014 ICS 91.120.10; 91.140.01
5、Supersedes EN 14114:2002English Version Hygrothermal performance of building equipment and industrial installations - Calculation of water vapour diffusion - Cold pipe insulation systems (ISO 15758:2014) Performance hygrothermique des quipements de btiments et installations industrielles - Calcul de
6、 la diffusion de vapeur deau - Systmes disolation de tuyauteries froides (ISO 15758:2014) Wrmedmmung von haus- und betriebstechnischen Anlagen in Gebuden - Berechnung der Wasserdampfdiffusion - Dmmung von Klteleitungen (ISO 15758:2014) This European Standard was approved by CEN on 20 March 2014. CEN
7、 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 bibliographical references concerning such national standards may be obtained on appl
8、ication 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 of a CEN member into its own language and notified to the CEN-CENELEC Ma
9、nagement 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 Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Lat
10、via, 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 EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Mar
11、nix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 15758:2014 EBS EN ISO 15758:2014EN ISO 15758:2014 (E) 3 Foreword This document (EN ISO 15758:2014) has been prepared by Technical Committee ISO/TC 163
12、 “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 standard, either by pu
13、blication of an identical text or by endorsement, at the latest by November 2014, and conflicting national standards shall be withdrawn at the latest by November 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CEN
14、ELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 14114:2002. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium
15、, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerla
16、nd, Turkey and the United Kingdom. Endorsement notice The text of ISO 15758:2014 has been approved by CEN as EN ISO 15758:2014 without any modification. BS EN ISO 15758:2014ISO 15758:2014(E) ISO 2014 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Te
17、rms, definitions and symbols 14 Calculation formulae 34.1 General . 34.2 Homogeneous insulation . 34.3 Multi-layer insulation systems 44.4 Systems with capacity for drying 45 Boundary conditions 56 Calculation procedure 66.1 General . 66.2 Calculation of rate of condensation in single homogenous ins
18、ulation layer .66.3 Calculation of rate of condensation in multi-layer insulation system . 6Annex A (informative) Examples 9Annex B (informative) System with capacity for drying and experimental determination of evaporation rate from surface of wet wick fabric .11Bibliography .15BS EN ISO 15758:2014
19、ISO 15758:2014(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national 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 subje
20、ct for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC
21、) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be no
22、ted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directivesAttention 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 o
23、r all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received. www.iso.org/patentsAny trade name used in this document is information given for the convenience of users and d
24、oes not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary infor
25、mationThe committee responsible for this document is ISO/TC 163, Thermal performance and energy use in the built environment, Subcommittee SC 2, Calculation methods.This second edition cancels and replaces the first edition (ISO 15758:2004), which has been technically revised. The main changes are t
26、he following: in Clause 5, b), the alternative of using annual mean temperature and vapour pressure has been removed; the method of calculation given in 6.3 has been changed such that the total amount of condensation water in the whole pipe system is calculated based only on the outermost tangent to
27、 the saturation pressure, psat; Figure 1 has been modified; the example given in A.3 has been changed; in Annex B, an explanation of the system with capacity for drying has been added; references have been added to the Bibliography.iv ISO 2014 All rights reservedBS EN ISO 15758:2014ISO 15758:2014(E)
28、IntroductionIf the thermal insulation of a cold pipe system is not completely water vapour tight, there will be a flow of water vapour from the warm environment to the surface of the pipe, whenever the temperature of the surface of the cold pipe is below the dew point of the ambient air. This flow o
29、f water vapour leads to an interstitial condensation in the insulation layer and/or dew formation on the surface of the pipe itself. Interstitial condensation may cause the insulation material to deteriorate and dew formation on the surface of a metal pipe may cause corrosion over time. If the tempe
30、rature is below 0 C ice will be formed and the methods of this standard will not apply.In period, when the dew point of the ambient air is higher than the temperature of the outer surface of the insulation, surface condensation will occur. This is dealt with in ISO 12241.Different measures are avail
31、able to control water vapour transfer and reduce the amount of condensation. The following are normally applied:a) Installation of a vapour retarder;b) Use of insulation materials with a high water vapour resistance factor (low permeability);c) Use of a vapour retarder and a capillary active fabric
32、to continuously remove condensed water from the pipe surface to the environment; see Annex B for an example.Which protection measure is chosen depends on the ambient climate, the temperature of the medium in the pipe and the water vapour diffusion resistance of the insulation layer. The success of a
33、ny system is strongly dependent on workmanship and maintenance. In any case anti-corrosion measures should be applied to a metal pipe in severe conditions.The expected economic lifetime of an insulation system, assuming a maximum acceptable accumulated moisture content, can be calculated using the m
34、ethods in this standard. ISO 2014 All rights reserved vBS EN ISO 15758:2014BS EN ISO 15758:2014Hygrothermal performance of building equipment and industrial installations Calculation of water vapour diffusion Cold pipe insulation systems1 ScopeThis International Standard specifies a method for calcu
35、lating the density of the water vapour flow rate in cold pipe insulation systems, and the total amount of water diffused into the insulation over time. The calculation method presupposes that water vapour can only migrate into the insulation system by diffusion, with no contribution from airflow. It
36、 also assumes the use of homogeneous, isotropic insulation materials so that the water vapour partial pressure is constant at all points equidistant from the axis of the pipe.This International Standard is applicable when the temperature of the medium in the pipe is above 0 C. It applies to pipes in
37、side buildings as well as in the open air.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the
38、 referenced document (including any amendments) applies.ISO 9346, Hygrothermal performance of buildings and building materials Physical quantities for mass transfer VocabularyISO 12241, Thermal insulation for building equipment and industrial installations Calculation rulesISO 12572, Hygrothermal pe
39、rformance of building materials and products Determination of water vapour transmission propertiesISO 13788, Hygrothermal performance of building components and building elements Internal surface temperature to avoid critical surface humidity and interstitial condensation Calculation methods3 Terms,
40、 definitions and symbolsFor the purposes of this document, the terms and definitions given in ISO 9346, ISO 12572 and ISO 13788, and the following terms, definitions and symbols (see Table 1) apply.3.1exposed moist areasurface area of a capillary active fabric that is exposed to the ambient atmosphe
41、re3.2vapour retardermaterial with high resistance to the flow of water vapour3.3corrected water vapour diffusion equivalent air layer thicknessthickness of an imaginary plane layer with =1, and an area of Djwhich has the same diffusion resistance as the layer j with = jNote 1 to entry: See Formula (
42、18).INTERNATIONAL STANDARD ISO 15758:2014(E) ISO 2014 All rights reserved 1BS EN ISO 15758:2014ISO 15758:2014(E)Table 1 Symbols and associated unitsSymbol Quantity UnitaAeSurface area from which evaporation takes place per linear metre of the pipem2/mD0Outside diameter of cold pipe mDjOutside diamet
43、er of j-th layer of an insulation system mDnOutside diameter of the outer layer of an insulation system mG Total moisture uptake over a period per linear metre of pipe refer to Formula (2)kg/mG Total moisture uptake over a period per linear metre of pipe kg/mP Actual atmospheric pressure PaP0Standar
44、d atmospheric pressure = 101 325 PaRvGas constant for water vapour = 461,5 J/(kgK)T Thermodynamic temperature KZflWater vapour resistance of one thin foil, cladding or skin per linear metre of pipemsPa/kgZjWater vapour resistance of j-th layer of an insulation system per lin-ear metre of pipemsPa/kg
45、ZPWater vapour resistance of insulation system per linear metre of pipe msPa/kgd Thickness of an insulation layer mfeEvaporation factor kg/(m2sPa)g Water vapour flow rate within the insulation per linear metre of pipe kg/(ms)gcRate of condensation per linear metre of pipe kg/(ms)geEvaporation rate p
46、er linear metre of pipe kg/(ms)hcConvection heat transfer coefficient W/(m2K)p Partial water vapour pressure PapaPartial water vapour pressure of air PapsatSaturated water vapour pressure PasdWater vapour diffusion equivalent air layer thickness msdfWater vapour diffusion equivalent air layer thickn
47、ess of foils mt Period of calculation (month or year) Month, yearx Distance m Water vapour permeability kg/(msPa)0Water vapour permeability of air kg/(msPa)d,jCorrected water vapour diffusion equivalent air layer thickness of layer jmd, jTotal corrected water vapour diffusion equivalent air layer th
48、ickness from surface of cold pipe to the outside of layer jm Water vapour resistance factor 0Temperature of the medium in the pipe CaFor practical reasons, hours or days are often used instead of seconds as units of time.2 ISO 2014 All rights reservedBS EN ISO 15758:2014ISO 15758:2014(E)4 Calculatio
49、n formulae4.1 GeneralThe density of water vapour flow rate, g, through a material is calculated by the following formula:gpx=dd(1)where is the water vapour permeability of the material.The total moisture uptake during a period, G, is given byGgtt=d0(2)In calculations the diffusion resistance factor, , is commonly used instead of the permeability:=0(3)where 0is the water vapour permeability of still air, which can be calculated from001810 083273=,PRTPTV(4)For approx
