EN ISO 11855-1:2021/A1:2023

SLOVENSKI STANDARD
01-december-2023
Načrtovanje notranjega okolja v stavbah - Vgrajeni sevalni ogrevalni in hladilni
sistemi - 1. del: Definicije, simboli in merila za ugodje - Dopolnilo A1 (ISO 11855-
1:2021/Amd 1:2023)
Building environment design - Embedded radiant heating and cooling systems - Part 1:
Definitions, symbols, and comfort criteria - Amendment 1 (ISO 11855-1:2021/Amd
1:2023)
Umweltgerechte Gebäudeplanung - Flächenintegrierte Strahlungsheiz- und
–kühlsysteme - Teil1: Begriffe, Symbole und Behaglichkeitskriterien - Änderung 1 (ISO
11855-1:2021/Amd 1:2023)
Conception de l'environnement des bâtiments - Systèmes intégrés de chauffage et de
refroidissement par rayonnement - Partie 1: Définitions, symboles et critères de confort -
Amendement 1 (ISO 11855-1:2021/Amd 1:2023)
Ta slovenski standard je istoveten z: EN ISO 11855-1:2021/A1:2023
ICS:
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
91.140.30 Prezračevalni in klimatski Ventilation and air-
sistemi conditioning systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 11855-1:2021/A1
EUROPEAN STANDARD
NORME EUROPÉENNE
October 2023
EUROPÄISCHE NORM
ICS 91.040.01
English Version
Building environment design - Embedded radiant heating
and cooling systems - Part 1: Definitions, symbols, and
comfort criteria - Amendment 1 (ISO 11855-1:2021/Amd
1:2023)
Conception de l'environnement des bâtiments - Umweltgerechte Gebäudeplanung - Flächenintegrierte
Systèmes intégrés de chauffage et de refroidissement Strahlungsheiz- und Kühlsysteme - Teil 1: Begriffe,
par rayonnement - Partie 1: Définitions, symboles et Symbole und Behaglichkeitskriterien - Änderung 1
critères de confort - Amendement 1 (ISO 11855- (ISO 11855-1:2021/Amd 1:2023)
1:2021/Amd 1:2023)
This amendment A1 modifies the European Standard EN ISO 11855-1:2021; it was approved by CEN on 26 September 2023.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for inclusion of
this amendment into the relevant 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 amendment 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11855-1:2021/A1:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 11855-1:2021/A1:2023) has been prepared by Technical Committee ISO/TC
205 "Building environment design" in collaboration with Technical Committee CEN/TC 228 “Heating
systems and water based cooling systems in buildings” the secretariat of which is held by DIN.
This Amendment to the European Standard EN ISO 11855-1:2021 shall be given the status of a national
standard, either by publication of an identical text or by endorsement, at the latest by April 2024, and
conflicting national standards shall be withdrawn at the latest by April 2024.
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.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 11855-1:2021/Amd 1:2023 has been approved by CEN as EN ISO 11855-
1:2021/A1:2023 without any modification.

INTERNATIONAL ISO
STANDARD 11855-1
Second edition
2021-08
AMENDMENT 1
2023-09
Building environment design —
Embedded radiant heating and cooling
systems —
Part 1:
Definitions, symbols, and comfort
criteria
AMENDMENT 1
Conception de l'environnement des bâtiments — Systèmes intégrés de
chauffage et de refroidissement par rayonnement —
Partie 1: Définitions, symboles et critères de confort
AMENDEMENT 1
Reference number
ISO 11855-1:2021/Amd.1:2023(E)
ISO 11855-1:2021/Amd.1:2023(E)
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 11855-1:2021/Amd.1:2023(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).
ISO draws attention to the possibility that the implementation of this document may involve the use
of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed
patent rights in respect thereof. As of the date of publication of this document, ISO had not received
notice of (a) patent(s) which may be required to implement this document. However, implementers are
cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all
such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of 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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 205, Building environment design, in
collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC
228, Heating systems and water based cooling systems in buildings, in accordance with the Agreement on
technical cooperation between ISO and CEN (Vienna Agreement).
A list of all parts in the ISO 11855 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iii
ISO 11855-1:2021/Amd.1:2023(E)
Building environment design — Embedded radiant heating
and cooling systems —
Part 1:
Definitions, symbols, and comfort criteria
AMENDMENT 1
Contents
Modify the title of 5.4.3 as follows:
5.4.3 Acoustical comfort in thermo active building systems (TABS)

Foreword
Add the following sentence to the revision paragraph:
The main changes are as follows:
— radiant systems are newly classified into types according to the differences in the calculation
method to determine the thermal output of the system;
— Annex C, which summarizes the characteristics of the newly classified radiant system types, has
been added for easy reference.

Clause 4
Modify the rows in Table 1 as follows:
S m Thickness of the screed (excluding the pipes in the system type I)
s In the system type II, thickness of thermal insulation from the outward edge
h
m
of the insulation to the inward edge of the pipes (see Figure 1)
s In the system type II, thickness of thermal insulation from the outward edge
l
m
of the insulation to the outward edge of the pipes (see Figure 1)

5.3.3, Figure 1
Modify the figure key as follows:
Key
X vertical air temperature difference between head and feet, in K
Y percentage dissatisfied, in %

ISO 11855-1:2021/Amd.1:2023(E)
5.4.3
Modify the title as follows:
5.4.3 Acoustical comfort in thermo active building systems (TABS)

Clause 6
Add a new Clause 6 after Clause 5.

6  Types of radiant system
6.1  General
Radiant systems are classified into types according to the differences in the calculation method to
determine the thermal output of the system. The configuration of each system type was explained by
the main elements and layers constituting the system.
Radiant system types are composed of a combination of some, or all of the following main elements and
layers:
— Ag: air gap
— Ct: capillary tubes
— In: thermal insulation layer
— Pe: pipes or electric cables
— Pt: protection layer
— Sc: structural construction
— Sf: surface layer
— St: structural layer
— Su: surface layer
— Tc: thermal conduction layer
— Td: thermal diffusion layer
— Tr: thermal reflection layer
The thermal diffusion layer also has a function of weight distribution in the floor application. Depending
on whether the radiant system is heating or cooling, a heated or a cooled thermal medium is supplied
through pipes. The pipes shown in the types of radiant system are electric cables for electrical heating
systems.
The thermal output of a radiant system can be obtained from the thermal output calculation methods
according to radiant system types described in ISO 11855-2. For radiant systems that do not belong to
the types of radiant system, thermal output can be obtained by measurement or detailed calculation
methods by finite difference or finite element method.
In the description of each radiant system type, the main characteristics of the system type, the
variant radiant systems that belong to this type, thermal medium and installation method, methods
for determining the thermal output, application, and previous system types that belong to this type
ISO 11855-1:2021/Amd.1:2023(E)
are included. A clear definition of the radiant system types allows the proper design, dimensioning,
installation and control of the system.
Tables summarizing the characteristics of the newly classified radiant system types are given in
Annex C. Tables C.1 to C.5 facilitate the understanding of the new types of radiant system and can be
used for quick reference and citation.
6.2  Radiant system Type I — Pipes directly included in a thermal diffusion layer
The system is characterized by the installation of pipes embedded in the screed. Above the screed
different floor coverings can be arranged. The main feature of the construction is that the pipes are
completely embedded in a support layer. The system can be constructed with and without an insulation
layer. See Figure 2.
For the determination of thermal output, a calculation method is used if the system is in applicable
boundary conditions. If the system is not in applicable boundary conditions, the measurement method
shall be applied.
The system can be used as a heating and cooling system, installed in floors, walls, and ceilings.
In the old types of radiant system, Types A, C, H, J and I belong to this category.
Key
In thermal insulation layer
Pe pipes or electric cables
Pt protection layer
Sf surface layer
St structural layer
Td thermal
...