IEC 60704-2-6:2003

INTERNATIONAL IEC
STANDARD
60704-2-6
Second edition
2003-01
Household and similar electrical appliances –
Test code for the determination of airborne
acoustical noise –
Part 2-6:
Particular requirements for tumble dryers
Appareils électrodomestiques et analogues –
Code d'essai pour la détermination du bruit aérien –
Partie 2-6:
Règles particulières pour les sèche-linge à tambour
Reference number
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INTERNATIONAL IEC
STANDARD
60704-2-6
Second edition
2003-01
Household and similar electrical appliances –
Test code for the determination of airborne
acoustical noise –
Part 2-6:
Particular requirements for tumble-dryers
Appareils électrodomestiques et analogues –
Code d'essai pour la détermination du bruit aérien –
Partie 2-6:
Règles particulières pour les sèche-linge à tambour
 IEC 2003  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 60704-2-6  IEC:2003(E)
CONTENTS
FOREWORD . 3
INTRODUCTION .5
1 Scope and object . 6
2 Normative references. 7
3 Terms and definitions. 7
4 Measurement methods and acoustical environments . 8
5 Instrumentation .8
6 Operation and location of appliances under test. 8
7 Measurement of sound pressure levels.11
8 Calculation of sound pressure and sound power levels .11
9 Information to be recorded .11
10 Information to be reported .11
Annexes.14
Annex AA (informative) Standard muffler: list of possible types .14
Figure 101 – Test enclosure .12
Figure 102 – Standard exhaust system .13

60704-2-6  IEC:2003(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION OF AIRBORNE
ACOUSTICAL NOISE –
Part 2-6: Particular requirements for tumble dryers
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60704-2-6 has been prepared by subcommittee 59D: Home laundry
appliances, of IEC technical committee 59: Performance of household electrical appliances.
This second edition cancels and replaces the first edition published in 1994 and constitutes a
technical revision.
The text of this publication is based on the following documents:
FDIS Report on Voting
59D/224/FDIS 59D/227/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
This Part 2-6 is intended to be used in conjunction with IEC 60704-1, 2nd edition 1997:
Household and similar electrical appliances – Test code for the determination of airborne
acoustical noise – Part 1: General requirements.

– 4 – 60704-2-6  IEC:2003(E)
The relevant text of Part 1 as amended by this standard establishes the test code for tumble
dryers.
This Part 2-6 supplements or modifies the corresponding clauses in IEC 60704-1. When a
particular subclause of Part 1 is not mentioned in this part 2-6, that subclause is applicable as
far as reasonable. Where this standard states “addition”, “modification” or “replacement”, the
relevant requirements, test specifications or explanatory matter in part 1 shall be adapted
accordingly.
Subclauses or figures which are additional to those in Part 1 are numbered starting from 101.
Additional annexes are lettered AA, BB, etc.
Unless notes are in a new subclause or involve notes in Part 1, they are numbered starting
from 101, including those in a replaced clause or subclause.
The committee has decided that the contents of this publication will remain unchanged until 2005.
At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

60704-2-6  IEC:2003(E) – 5 –
INTRODUCTION
The measuring conditions specified in this part of IEC 60704 provide for sufficient accuracy in
determining the levels of noise emitted and comparing the results of measurements taken by
different laboratories, whilst simulating as far as possible the practical use of tumble dryers.
It is recommended to consider the determination of noise levels as part of a comprehensive
testing procedure covering many aspects of properties and performance of household tumble
dryers.
Compared to the first edition (1994) of this Part 2-6, the second edition considers the noise
during a complete drying cycle.
NOTE As stated in the introduction to IEC 60704-1, this test code concerns airborne noise only.

– 6 – 60704-2-6  IEC:2003(E)
HOUSEHOLD AND SIMILAR ELECTRICAL APPLIANCES –
TEST CODE FOR THE DETERMINATION
OF AIRBORNE ACOUSTICAL NOISE –
Part 2-6: Particular requirements for tumble dryers
1 Scope and object
This clause of Part 1 is applicable except as follows.
1.1 Scope
1.1.1 General
Replacement:
This standard applies to single unit electric tumble dryers for household and similar use
intended for placing on the floor against a wall, for building in or placing under a counter, a
kitchen work-top or under a sink, for wall-mounting or for mounting on a counter. For the
purpose of this standard, washer-dryer combinations, when operated as a dryer, are
considered as a tumble dryer.
Limitations for the use of this test code are given in 1.1.1 of IEC 60704-1.
1.1.2 Types of noise
Replacement:
ISO 3743-1, ISO 3743-2 and ISO 3744 can all be used for measuring noise emitted by tumble
dryers.
1.1.3 Size of the source
Replacement:
The method specified in ISO 3744 is applicable to noise sources of any size. When applying
ISO 3743-1 and ISO 3743-2, care shall be taken that the maximum size of the tumble dryer
under test fulfils the requirements specified in 1.3 of ISO 3743-1 and ISO 3743-2.
1.2 Object
Addition:
Requirements for the declaration of noise emission values are not within the scope of this
standard.
NOTE 101 For determining and verifying noise emission values declared in product specifications, see IEC 60704-3.
1.3 Measurement uncertainty
Replacement:
The estimated values of standard deviations of sound power levels, determined according to
this standard, are:
60704-2-6  IEC:2003(E) – 7 –
Standard deviation
dB
σσσσ (repeatability) σσσσ (reproducibility)
r R
0,4 0,8
Addition:
1.101 Standard deviation for declaration and verification
For the purpose of determining and verifying declared noise emission values, according to
IEC 60704-3, the following values apply for the:
– standard deviation of production σ ;
P
– total standard deviation σ ;
t
– reference standard deviation σ .
M
Standard deviation
dB
σσσσ σσσσ σσσσ
P t M
0,7 – 1,0 1,1 – 1,3 1,5
2 Normative references
This clause of Part 1 is applicable except as follows.
Addition:
IEC 61121:2000, Tumble dryers for household use – Methods for measuring the performance
ISO/3055:1985, Kitchen equipment – Coordinating sizes
ISO 7235:1991, Acoustics – Measurement procedures for ducted silencers – Insertion loss,
flow noise and total pressure loss
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
3.4 Operational cycle
Addition:
Start and end of the operational cycle are identical to those applied for energy and time
measurements as defined in 9.2.1 of IEC 61121.
Addition:
3.101
standard test programme for noise measurements
for the purposes of the present standard, the dry cotton programme according to 9.2.1 of
IEC 61121
– 8 – 60704-2-6  IEC:2003(E)
3.102
standard test load for noise measurements
the cotton test load for the same rated capacity and, with the same initial moisture content
A or B, defined in 7.3.4 of IEC 61121.
NOTE New textile items should be washed as described in 7.3.2 of IEC 61121. An item should not be used more
than 80 cycles after pre-treatment.
3.103
cotton test load
load as defined in 7.1.1 of IEC 61121
3.104
rated capacity
capacity as defined in 3.11 and 5 of IEC 61121
3.105
initial moisture content
moisture content achieved by wetting as described in 7.3.4. of IEC 61121
4 Measurement methods and acoustical environments
This clause of Part 1 is applicable except as follows.
4.1 General
Addition:
The noise emission of a tumble dryer is the value of the A-weighted time-averaged sound
power level over the total duration of the operational cycle.
4.2 Direct method
Addition:
NOTE 101 If pure tone components are present in the noise emitted, proper precautions should be taken as
specified in ISO 3743-2.
4.3 Comparison method
Addition:
NOTE 101 If pure tone components are present in the noise emitted, proper precautions should be taken as
specified in ISO 3743-1 and ISO 3743-2.
5 Instrumentat
...