SIST EN ISO 13786:2017

SLOVENSKI STANDARD
SIST EN ISO 13786:2017
01-september-2017
Nadomešča:
SIST EN ISO 13786:2008
Toplotne značilnosti delov stavb - Dinamične toplotne značilnosti - Računske
metode (ISO 13786:2017, popravljena različica 2018-03)
Thermal performance of building components - Dynamic thermal characteristics -
Calculation methods (ISO 13786:2017, Corrected version 2018-03)
Wärmetechnisches Verhalten von Bauteilen - Dynamisch-thermische Kenngrößen -
Berechnungsverfahren (ISO 13786:2017)
Performance thermique des composants de bâtiment - Caractéristiques thermiques
dynamiques - Méthodes de calcul (ISO 13786:2017)
Ta slovenski standard je istoveten z: EN ISO 13786:2017
ICS:
91.120.10 Toplotna izolacija stavb Thermal insulation of
buildings
SIST EN ISO 13786:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 13786:2017

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SIST EN ISO 13786:2017


EN ISO 13786
EUROPEAN STANDARD

NORME EUROPÉENNE

July 2017
EUROPÄISCHE NORM
ICS 91.060.01; 91.120.10 Supersedes EN ISO 13786:2007
English Version

Thermal performance of building components - Dynamic
thermal characteristics - Calculation methods (ISO
13786:2017, Corrected version 2018-03)
Performance thermique des composants de bâtiment - Wärmetechnisches Verhalten von Bauteilen -
Caractéristiques thermiques dynamiques - Méthodes Dynamisch-thermische Kenngrößen -
de calcul (ISO 13786:2017) Berechnungsverfahren (ISO 13786:2017)
This European Standard was approved by CEN on 27 February 2017.

This European Standard was corrected and reissued by the CEN-CENELEC Management Centre on 21 November 2018.

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 bibliographical 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 of 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 Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N

EUROPÄISCHES KOMITEE FÜR NORMUN G

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13786:2017 E
worldwide for CEN national Members.

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SIST EN ISO 13786:2017
EN ISO 13786:2017 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 13786:2017
EN ISO 13786:2017 (E)
European foreword
This document (EN ISO 13786:2017) has been prepared by Technical Committee 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 standard, either by publication of an
identical text or by endorsement, at the latest by January 2018 and conflicting national standards shall
be withdrawn at the latest by January 2018.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
This document is part of the set of standards and accompanying technical reports on the energy
performance of buildings and has been prepared under a mandate given to CEN by the European
Commission and the European Free Trade Association (Mandate M/480, see reference [EF3] below).
Directive 2010/31/EU recasting the Directive 2002/91/EC on energy performance of buildings (EPBD,
[EF4]) promotes the improvement of the energy performance of buildings within the European Union,
taking into account all types of energy uses (heating, lighting, cooling, air conditioning, ventilation) and
outdoor climatic and local conditions, as well as indoor climate requirements and cost effectiveness
(Article 1).
The directive requires Member States to adopt measures and tools to achieve the prudent and rational
use of energy resources. In order to achieve those goals, the EPBD requires increasing energy efficiency
and the enhanced use of renewable energies in both new and existing buildings. One tool for this is the
application by Member States of minimum requirements on the energy performance of new buildings
and for existing buildings that are subject to major renovation, as well as for minimum performance
requirements for the building envelope if energy-relevant parts are replaced or retrofitted. Other tools
are energy certification of buildings, inspection of boilers and air-conditioning systems.
The use of European standards increases the accessibility, transparency and objectivity of the energy
performance assessment in the Member States facilitating the comparison of best practices and
supporting the internal market for construction products. The use of EPB standards for calculating
energy performance, as well as for energy performance certification and the inspection of heating
systems and boilers, ventilation and air-conditioning systems will reduce costs compared to developing
different standards at national level.
The first mandate to CEN to develop a set of CEN EPBD standards (M/343, [EF1]), to support the first
edition of the EPBD ([EF2]) resulted in the successful publication of all EPBD related CEN standards in
2007-2008.
Mandate M/480 was issued to review the mandate M/343 as the recast of the EPBD raised the need to
revisit the standards and reformulate and add standards so that they become on the one hand
unambiguous and compatible, and on the other hand a clear and explicit overview of the choices,
boundary conditions and input data that need to be defined at national or regional level. Such national
or regional choices remain necessary, due to differences in climate, culture and building tradition,
3

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SIST EN ISO 13786:2017
EN ISO 13786:2017 (E)
policy and legal frameworks. Consequently, the set of CEN EPBD standards published in 2007-2008 had
to be improved and expanded on the basis of the recast of the EPBD.
The EPB standards are flexible enough to allow for necessary national and regional differentiation and
facilitate Member States implementation and the setting of requirements by the Member States.
Further target groups are users of the voluntary common European Union certification scheme for the
energy performance of non-residential buildings (EPBD article 11.9) and any other regional (e.g. pan
European) parties wanting to motivate their assumptions by classifying the building energy
performance for a dedicated building stock.
This document supersedes EN ISO 13786:2007.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, 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, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
References:
[EF1] EPBD, Directive 2002/91/EC of the European Parliament and of the Council of 16 December
2002 on the energy performance of buildings
[EF2] EPBD Mandate M/343, Mandate to CEN, CENELEC and ETSI for the elaboration and adoption of
standards for a methodology calculating the integrated energy performance of buildings and estimating
the environmental impact, in accordance with the terms set forth in Directive 2002/91/EC , 30 January
2004
[EF3] Mandate M/480, Mandate to CEN, CENELEC and ETSI for the elaboration and adoption of
standards for a methodology calculating the integrated energy performance of buildings and promoting
the energy efficiency of buildings, in accordance with the terms set in the recast of the Directive on the
energy performance of buildings (2010/31/EU), 14 December 2010
[EF4] EPBD, Recast of the Directive on the energy performance of buildings (2010/31/EU). 14
December 2010
Endorsement notice
The text of ISO 13786:2017, Corrected version 2018-03 has been approved by CEN as EN
ISO 13786:2017 without any modification.

4

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SIST EN ISO 13786:2017
INTERNATIONAL ISO
STANDARD 13786
Third edition
2017-06
Corrected version
2018-03
Thermal performance of building
components — Dynamic thermal
characteristics — Calculation methods
Performance thermique des composants de bâtiment —
Caractéristiques thermiques dynamiques — Méthodes de calcul
Reference number
ISO 13786:2017(E)
©
ISO 2017

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SIST EN ISO 13786:2017
ISO 13786:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Ch. de Blandonnet 8 • CP 401
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved

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SIST EN ISO 13786:2017
ISO 13786:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Definitions valid for any component . 2
3.2 Definitions valid only for one dimensional heat flow . 3
3.3 Other . 5
4 Symbols and subscripts . 5
4.1 Symbols . 5
4.2 Subscripts . 6
4.3 Specific symbols . 6
5 Description of the method . 6
5.1 Output . 6
5.2 General description . 6
6 Calculation of dynamic thermal properties . 6
6.1 Output data . 6
6.2 Calculation time intervals . 7
6.3 Input data . 7
6.4 Period of the thermal variations . 8
6.5 Heat capacity . 8
7 Heat transfer matrix of a multi-layer component . 8
7.1 General . 8
7.2 Procedure . 8
7.3 Heat transfer matrix of a homogeneous layer. 9
7.4 Heat transfer matrix of plane air cavities . 9
7.5 Heat transfer matrix of a building component . 9
8 Dynamic thermal characteristics .10
8.1 Characteristics for any component .10
8.2 Characteristics for components consisting of plane and homogeneous layers .10
8.2.1 Thermal admittances and periodic thermal conductances .10
8.2.2 Modified admittance for internal partitions .10
8.2.3 Areal heat capacities .10
8.2.4 Periodic thermal transmittance and decrement factor .11
9 Report .11
9.1 Calculation report .11
9.2 Summary of results .12
Annex A (normative) Input and method selection data sheet — Template .13
Annex B (informative) Input and method selection data sheet — Default choices .15
Annex C (normative) Simplified calculation of the heat capacity .17
Bibliography .19
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SIST EN ISO 13786:2017
ISO 13786:2017(E)

Foreword
ISO (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 subject 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) 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 noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
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. 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 (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
ISO 13786 was prepared by ISO Technical Committee ISO/TC 163, Thermal performance and energy use
in the built environment, Subcommittee SC 2, Calculation methods, in collaboration with the European
Committee for Standardization (CEN) Technical Committee CEN/TC 89, Thermal performance of
buildings and building components, in accordance with the Agreement on technical cooperation between
ISO and CEN (Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 13786:2007), which has been technically
revised.
The changes in the third edition are mostly editorial. This document has been re-drafted according to
CEN/TS 16629:2014.
This corrected version of ISO 13786 incorporates the following correction:
2 2
— In Formula (C.5) the symbol É has been corrected to ω .
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SIST EN ISO 13786:2017
ISO 13786:2017(E)

Introduction
This document is part of a series aimed at the international harmonization of the methodology for
assessing the energy performance of buildings. Throughout, this series is referred to as a “set of EPB
standards”.
All EPB standards follow specific rules to ensure overall consistency, unambiguity and transparency.
All EPB standards provide a certain flexibility with regard to the methods, the required input data and
references to other EPB standards, by the introduction of a normative template in Annex A and Annex B
with informative default choices.
For the correct use of this document, a normative template is given in Annex A to specify these choices.
Informative default choices are provided in Annex B.
The main target groups for this document are architects, engineers and regulators.
Use by or for regulators: In case the document is used in the context of national or regional legal
requirements, mandatory choices may be given at national or regional level for such specific
applications. These choices (either the informative default choices from Annex B or choices adapted to
national/regional needs, but in any case following the template of Annex A) can be made available as
national annex or as separate (e.g. legal) document (national data sheet).
NOTE 1 So in this case:
— the regulators will specify the choices;
— the individual user will apply the document to assess the energy performance of a building, and thereby use
the choices made by the regulators.
Topics addressed in this document can be subject to public regulation. Public regulation on the same
topics can override the default values in Annex B. Public regulation on the same topics can even, for
certain applications, override the use of this document. Legal requirements and choices are in general
not published in standards but in legal documents. In order to avoid double publications and difficult
updating of double documents, a national annex may refer to the legal texts where national choices
have been made by public authorities. Different national annexes or national data sheets are possible,
for different applications.
It is expected, if the default values, choices and references to other EPB standards in Annex B are not
followed due to national regulations, policy or traditions, that:
— national or regional authorities prepare data sheets containing the choices and national or regional
values, according to the model in Annex A. In this case a national annex (e.g. NA) is recommended,
containing a reference to these data sheets;
— or, by default, the national standards body will consider the possibility to add or include a national
annex in agreement with the template of Annex A, in accordance to the legal documents that give
national or regional values and choices.
Further target groups are parties wanting to motivate their assumptions by classifying the building
energy performance for a dedicated building stock.
More information is provided in the Technical Report (ISO/TR 52019-2) accompanying this document.
The subset of EPB standards prepared under the responsibility of ISO/TC 163/SC 2 cover inter alia:
— calculation procedures on the overall energy use and energy performance of buildings;
— calculation procedures on the internal temperature in buildings (e.g. in case of no space heating or
cooling);
— indicators for partial EPB requirements related to thermal energy balance and fabric features;
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SIST EN ISO 13786:2017
ISO 13786:2017(E)

— calculation methods covering the performance and thermal, hygrothermal, solar and visual
characteristics of specific parts of the building and specific building elements and components, such
as opaque envelope elements, ground floor, windows and facades.
ISO/TC 163/SC 2 cooperates with other technical committees for the details on appliances, technical
building systems, indoor environment, etc.
This document 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.
This document provides calculation methods for the dynamic thermal characteristics of a building
component. These characteristics describe the thermal behaviour of the component when it is subject
to variable boundary conditions, i.e. variable heat flow rate or variable temperature on one or both of
its boundaries. In this document, only sinusoidal boundary conditions are considered: boundaries are
submitted to sinusoidal variations of temperature or heat flow rate.
The properties considered are thermal admittances and thermal dynamic transfer properties, relating
cyclic heat flow rate to cyclic temperature variations. Thermal admittance relates heat flow rate to
temperature variations on the same side of the component. Thermal dynamic transfer properties relate
physical quantities on one side of the component to those on the other side. From the aforementioned
properties, it is possible to define the heat capacity of a given component which quantifies the heat
storage property of that component.
The dynamic thermal characteristics defined in this document can be used in product specifications of
complete building components.
The dynamic thermal characteristics can also be used in the calculation of:
— the internal temperature in a room,
— the daily peak power and energy needs for heating or cooling, and
— the effects of intermittent heating or cooling, etc.
Table 1 shows the relative position of this document within the set of EPB standards in the context of
the modular structure as set out in ISO 52000-1.
NOTE 2 In ISO/TR 52000-2, the same table can be found, with, for each module, the numbers of the relevant
EPB standards and accompanying technical reports that are published or in preparation.
NOTE 3 The modules represent EPB standards, although one EPB standard could cover more than one module
and one module could be covered by more than one EPB standard, for instance, a simplified and a detailed method
respectively. See also Tables A.1 and B.1.
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SIST EN ISO 13786:2017
ISO 13786:2017(E)

Table 1 — Position of this document (in casu M2–9) within the modular structure of the set of
EPB standards
Building
Overarching Technical building systems
(as such)
Buil
De Do ding
Hu
hu mes auto
Sub Ven mi PV,
Descrip Descrip Descrip Hea Coo mi tic Ligh ma
mo tila difi wind,
tions tions tions ting ling difi hot ting tion
dule tion ca .
ca wat and
tion
tion er cont
rol
sub1 M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11
1 General General General
Common
terms and
Building
definitions;
a
2 energy Needs
symbols,
needs
units and
subscripts
(Free) Indoor
Maximum
conditions
3 Applications load and
without
power
systems
Ways to ex- Ways to ex- Ways to ex-
4 press energy press energy press energy
performance performance performance
Building
Heat transfer
categories Emission
5 by transmis-
and building and control
sion
boundaries
Building Heat transfer
occupancy by infiltra- Distribution
6
and operating tion and and control
conditions ventilation
Aggregation
of energy
Internal heat Storage and
7 services
gains control
and energy
carriers
Building Solar heat Generation
8
zoning gains and control
Building Load dis-
Calculated
dynamics ISO patching and
9 energy per-
(thermal 13786 operating
formance
mass) conditions
Measured Measured Measured
10 energy per- energy per- energy per-
formance formance formance
11 Inspection Inspection Inspection
Ways to ex-
12 press indoor BMS
comfort
External
13 environment
conditions
Economic
14
calculation
a
The shaded modules are not applicable.
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SIST EN ISO 13786:2017

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SIST EN ISO 13786:2017
INTERNATIONAL STANDARD ISO 13786:2017(E)
Thermal performance of building components — Dynamic
thermal characteristics — Calculation methods
1 Scope
This document specifies the characteristics related to the dynamic thermal behaviour of a complete
building component and provides methods for
...