ISO 21978:2023

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 21978
ISO/TC 86/SC 6
Air to water heat pumps — Testing
Secretariat: JISC
and rating at part load conditions and
Voting begins on:
2023-08-18 calculation of seasonal coefficient of
performance for space heating
Voting terminates on:
2023-10-13
Chauffe-eau à pompe à chaleur — Essais et détermination des
caractéristiques à charge partielle et calcul de performance
saisonnière
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 21978:2023(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2023

---------------------- Page: 1 ----------------------
ISO/FDIS 21978:2023(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 21978
ISO/TC 86/SC 6
Air to water heat pumps — Testing
Secretariat: JISC
and rating at part load conditions and
Voting begins on:
calculation of seasonal coefficient of
performance for space heating
Voting terminates on:
Chauffe-eau à pompe à chaleur — Essais et détermination des
caractéristiques à charge partielle et calcul de performance
saisonnière
COPYRIGHT PROTECTED DOCUMENT
© 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.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
CH-1214 Vernier, Geneva
DOCUMENTATION.
Phone: +41 22 749 01 11
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: copyright@iso.org
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 21978:2023(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO 2023 – All rights reserved
NATIONAL REGULATIONS. © ISO 2023

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ISO/FDIS 21978:2023(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 8
5 Installation requirements .9
5.1 Test apparatus and uncertainties of measurement . 9
5.2 Test room for the airside . 10
5.3 Installation and connection of the heat pump . 10
5.4 Installation of heat pumps consisting of several parts . 11
5.5 Environment
...

ISO/FDIS 21978:2023(E)
ISO /TC 86/SC 6/WG 12
Secretariat: JISC
Date: 2023-08-04-19
Air to water heat pumps — Testing and rating at part load
conditions and calculation of seasonal coefficient of performance
for space heating
Chauffe-eau à pompe à chaleur — Essais et détermination des caractéristiques à charge partielle et calcul
de performance saisonnière
FDIS stage

---------------------- Page: 1 ----------------------
ISO/FDIS 21978:2023(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
EmailE-mail: copyright@iso.org
Website: www.iso.orgwww.iso.org
Published in Switzerland
ii © ISO 2023 – All rights reserved
ii © ISO 2023 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 21978:2023(E)
Contents
Foreword . viii
Introduction.ix
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 9
5 Installation requirements . 10
5.1 Test apparatus and uncertainties of measurement . 10
5.2 Test room for the airside . 11
5.3 Installation and connection of the heat pump . 12
5.4 Installation of heat pumps consisting of several parts . 12
5.5 Environment conditions for indoor unit installation and electrical power supply
requirements . 12
6 Setting and part load test conditions . 12
6.1 General . 12
6.2 Setting for capacity ratio . 12
6.3 Setting the external static pressure difference for ducted units . 13
6.4 Setting of units with integral pumps . 13
6.5 Part load test conditions . 13
7 Space heating test . 16
7.1 Heating capacity test . 16
7.2 Heating capacity correction . 17
7.2.1 General . 17
7.2.2 Capacity correction due to indoor liquid pump . 17
...