ISO/FDIS 13347-2
(Main)Fans — Determination of fan sound power levels under standardized laboratory conditions — Part 2: Reverberant room method
Fans — Determination of fan sound power levels under standardized laboratory conditions — Part 2: Reverberant room method
ISO 13347-2:2004 gives a detailed description of reverberant room methods for the determination of fan sound power levels. It is for use under standardized laboratory conditions and recognises that tests in situ are subject to increased uncertainty. These test procedures are not necessarily appropriate to site test conditions. Acoustic system effects are presently the subject of considerable research effort. ISO 5136, which covers the in-duct method, and ISO 10302 for small fans, should be used in conjunction with ISO 13347-2:2004.
Ventilateurs — Détermination des niveaux de puissance acoustique des ventilateurs dans des conditions de laboratoire normalisées — Partie 2: Méthode de la salle réverbérante
L'ISO 13347-2:2004 établit une description détaillée des méthodes en salle réverbérante pour la détermination des niveaux de puissance acoustique des ventilateurs. Elle est destinée à une utilisation dans des conditions de laboratoire normalisées, étant entendu que les essais sur site sont sujets à une incertitude accrue. Un tel mode opératoire d'essai n'est pas nécessairement appropriée aux conditions d'essais sur site. Les effets des systèmes acoustiques font actuellement l'objet d'importantes recherches. Il convient que l'ISO 5136, qui définit la méthode en conduit, ainsi que l'ISO 10302, traitant des ventilateurs de petite taille, soient utilisées conjointement avec l'ISO 13347-2:2004.
General Information
Relations
Buy Standard
Standards Content (Sample)
FINAL DRAFT
International
Standard
ISO/TC 117
Fans — Determination of fan sound
Secretariat: BSI
power levels under standardized
Voting begins on:
laboratory conditions —
2025-07-23
Part 2:
Voting terminates on:
2025-09-17
Reverberant room method
Ventilateurs — Détermination des niveaux de puissance
acoustique des ventilateurs dans des conditions de laboratoire
normalisées —
Partie 2: Méthode de la salle réverbérante
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
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
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.
Reference number
FINAL DRAFT
International
Standard
ISO/TC 117
Fans — Determination of fan sound
Secretariat: BSI
power levels under standardized
Voting begins on:
laboratory conditions —
Part 2:
Voting terminates on:
Reverberant room method
Ventilateurs — Détermination des niveaux de puissance
acoustique des ventilateurs dans des conditions de laboratoire
normalisées —
Partie 2: Méthode de la salle réverbérante
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.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
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 Reference number
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and Definitions . 2
3.1 Terms and definitions .2
3.2 Symbols and units .2
4 Field of application . 3
4.1 General .3
4.2 Noise and measurement parameters .3
4.2.1 Noise source .3
4.2.2 Character of noise . .3
4.2.3 Uncertainty .3
4.2.4 Quantities to be measured .3
5 Instrumentation . 3
6 Test method . 3
7 Acoustic environment . 4
7.1 Test environment .4
7.2 Reverberant room . .4
8 Test set-up and ducting . 4
8.1 Set-up categories .4
8.2 Sound pressure levels . . .8
8.2.1 Sound pressure levels, background (L ) .8
pb
8.2.2 Sound pressure levels, RSS (L ) .8
pqm
8.2.3 Sound pressure levels, fan (L ) .9
p
8.3 Aerodynamic performance .9
8.4 Test conditions .9
8.5 Mounting methods .9
8.6 Duct length .9
8.7 Microphone travel . . .10
9 Observations .11
9.1 Point of operation .11
9.2 Information to be recorded .11
10 Calculations .11
10.1 Background corrections .11
10.2 Sound power level, L . 12
W
Annex A (normative) Room qualification for sound sources with broad band sound .13
Annex B (informative) Room qualification for sound sources with pure tones/narrow-band
sound .15
Annex C (informative) Total fan sound testing with attached ducts .18
Annex D (normative) Transmission element .20
Bibliography .22
iii
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 document 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 117, Fans.
This second edition cancels and replaces the first edition (ISO 13347-2:2004), which has been technically
revised. It also incorporates the Technical Corrigendum ISO 13347-2:2004/Cor 1:2006.
The main changes are as follows:
— inclusion of acoustic methods for installation category E fans;
— symbols harmonized with ISO 5801 and those listed in normative references;
— editorial corrections.
A list of all parts in the ISO 13347 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.
iv
Introduction
This document deals with the determination of the fan sound power level appropriate to a particular
application. In describing the test and rating procedures, numerous references are made to ISO 5801 as
well as to other relevant ISO standards. This reverberant room method should be read in conjunction with
ISO 13447-1 and each part of the ISO 13347 series which details other
...
ISO/DISFDIS 13347-2:2024(en)
ISO/TC 117
Secretariat: BSI
Date: 20242025-07-1909
Fans — Determination of fan sound power levels under standardized
laboratory conditions —
Part 2:
Reverberant room method
Ventilateurs — Détermination des niveaux de puissance acoustique des ventilateurs dans des conditions de
laboratoire normalisées — Partie 2: Méthode de la salle réverbérante
Partie 2: Méthode de la salle réverbérante
FDIS stage
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'sISO’s member body in the country of the requester.
ISO Copyright Officecopyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Email: copyright@iso.org
E-mail: copyright@iso.org
Website: www.iso.orgwww.iso.org
Published in Switzerland.
ICS 17.140.20; 23.120
Price based on 22 pages
Error! Reference source not found.
ISO/DIS 13347-2:2024(en)
Contents Page
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and Definitions . 2
4 Field of application . 3
5 Instrumentation . 4
6 Test method . 4
7 Acoustic environment . 4
8 Test set-up and ducting . 4
9 Observations . 16
10 Calculations . 16
Annex A (normative) Room qualification for sound sources with broad band sound . 19
Annex B (informative) Room qualification for sound sources with pure tones/narrow-band
sound . 21
Annex C (informative) Total fan sound testing with attached ducts . 25
Annex D (normative) Transmission element . 27
Bibliography . 29
Foreword iii
Introduction iv
1 Scope . 1
2 Normative references . 1
3 Limitations on use . 2
4 Field of application . 2
5 Instrumentation . 3
6 Test method . 3
7 Acoustic environment . 3
8 Test set-up and ducting . 4
9 Observations . 14
10 Calculations . 14
Annex A (normative) Room qualification for sound sources with broad band sound . 17
Annex B (informative) Room qualification for sound sources with pure tones/narrow-band
sound . 19
iii
Annex C (informative) Total fan sound testing with attached ducts .23
Annex D (normative) Transmission element .26
Bibliography 28
ICS 17.140.20; 23.120
Price based on 22 pages
Error! Reference source not found.
ISO/DIS 13347-2:2024(en)
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 document 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.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.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 117, Fans.
This fourth edition cancels and replaces the third edition (ISO 13347-2:2004), which has been technically
revised. It also incorporates the Technical Corrigendum ISO 13347-2:2004/Cor 1:2006.
The main changes are as follows:
The main changes compared with ISO 13347-2:2004 are as follows:
— the inclusion of acoustic methods for installation category E fans;
— symbols have been harmonized with those used in ISO 5801 and other ISO standards as those listed
in Normativenormative references [2];
— editorial corrections have been incorporated.
A list of all parts in the ISO 13347 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.
Field Code Changed
v
Introduction
This document deals with the determination of the fan sound power level appropriate to a particular
application. In describing the test and rating procedures, numerous references are made to ISO 5801 as
well as to other relevant ISO standards. This reverberant room method should be read in conjunction
with ISO 13447-1 and each part of the ISO 13347 series which details other methods for determining the
sound power radiated by a fan in specified installation conditions as a function of frequency.
The method in this document employs standard sound measurement instrumentation. The test set-ups
are generally designed to represent the physical orientation of a fan as installed, in accordance with
ISO 5801 or ISO 13350.
This document primarily deals with the determination of sound power levels of fans used for ducted
applications.
The test procedures described in this document relate to laboratory conditions. The measurement of
performance under site conditions is not included. Acoustic system effects can be considerable where the
airflow into and out of the fan is not free from swirl, nor the velocity profile there fully developed.
This document describes methods for determining sound power levels of fans in one-third octave
bandwidths and one octave bandwidths.
Data obtained in accordance with this document may be used for the following purposes amongst others:
a) a) comparison of fans which are similar in size and type;
b) b) comparison of fans which are different in size and type;
c) c) determining whether a fan complies with a specified upper limit of sound emission;
d) d) scaling of fan noise from one size and speed to another size and speed;
e) e) prediction of sound pressure level in an installation of which the fan forms a part;
f) f) engineering work to assist in developing quiet machinery and equipment.
NOTE: The Bibliography of this document has furtherprovides additional references [0] to [0] for
those wishing to explore this subject in greater detail [1] to [19]
ICS 17.140.20; 23.120
Price based on 22 pages
Error! Reference source not found.
ISO/DISFDIS 13347-2:20242025(en)
Fans — Determination of fan sound power levels under standardized
laboratory conditions — Part 2: Reverberant room method
.
vii
DRAFT International Standard ISO/DIS 13347-2:2024(en)
Fans — Determination of fan sound power levels under standardized
laboratory conditions —
Part 2:
Reverberant room method
1 Scope
This document specifies determining sound power levels of fans under standardized laboratory conditions
from sound pressure levels measured in a reverberant room.
This document deals with theis applicable for determination of the acoustic performance of fans and, in
addition, may. This document can additionally be usedapplied to determine the acoustic performance of fans
combined with an ancillary device, such as a roof cowl or damper or, where the fan is fitted with a silencer,
the sound power resulting from the fan and silencer combination. For guidance of testing with ancillary items
see Annex C., see Annex C.
This document is intended to applyapplies to fans as defined in ISO 13349-1. It is limited to the determination
of airborne sound emission for the specified set-ups. Vibration is not measured, nor is the sensitivity of
airborne sound emission to vibration effects determined.
This document is intended to be used in conjunction with ISO 5136, which covers the in-duct method, and
ISO 10302-1 for small fans.
The size of the fanfans which can be tested in accordance with this document is limited only by the practical
aspects of the test set-up. Test fan dimensions and air performance will control the room size. (Small fans shall
be tested according to this standard or to ISO 10302-1, according to usage).
NOTE Based on usage, small fans can be tested according to this document or to ISO 10302-1.
For reverberant field tests, the size of equipment under test is limited to less than 2 % of the room volume.
For low power fans (up to 3 kW) that couldcan be run from a domestic power supply (single phase AC at a
voltage not exceeding 250 V and a current not exceeding 16 A), reference should be made to IEC 60704-2-
[ ]
7[18]. 0 .
The test arrangements in this document establish the laboratory conditions necessary for a successful test.
Rarely will it be possibleIt is difficult to meet these requirements in situ, and this document is not intended
for field measurements. Intended In these situations, users are reminded that, in these situations, the acoustic
environment is unlikely to meet the specified conditions and there may wellcan be additional acoustic system
effects where inlet and outlet conditions at the fan are less than ideal.
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 amendments) applies.
ISO/FDIS 1
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.