IEC 60704-2-6:2012

Household and similar electrical appliances - Test code for the determination of airborne acoustical noise - Part 2-6: Particular requirements for tumble dryers

IEC 60704-2-6:2012 is applicable to the methods of determination of airborne acoustical noise emitted by tumble dryers for household and similar use. This standard applies to single unit electric tumble dryers 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. This standard is also applicable for gas-fired electric tumble dryers. Key words: tumble dryers, airborne acoustical noise, dryers, noise
This publication is to be read in conjunction with IEC 60704-1:2010.

Appareils électrodomestiques et analogues - Code d'essai pour la détermination du bruit aérien - Partie 2-6: Règles particulières pour les sèche-linge à tambour

La CEI 60704-2-6:2012 donne le code d'essai pour la détermination du bruit aérien et s'applique aux sèche-linge électriques non combinés à tambour pour usages domestiques et analogues destinés à être placés sur le sol contre un mur, à être encastrés ou placés sous un élément, une table de travail ou un évier, à être fixés sur un mur ou dans un comptoir. Dans le cadre de la présente norme, des appareils combinés de lavage et séchage, quand ils sont utilisés en fonction séchage, sont considérés comme étant des sèche-linge à tambour. Cette norme s'applique également aux sèche-linge à tambour électriques et alimentés au gaz. Mots clés: sèche-linge, bruit aérien
Cette publication doit être lue conjointement avec la CEI 60704-1:2010.

General Information

• Status: Published
• Publication Date: 26-Mar-2012
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 17.140.20 - Noise emitted by machines and equipment
• ICS: 47.020.60 - Electrical equipment of ships and of marine structures
• ICS: 97.060 - Laundry appliances
• Technical Committee: SC 59D - Performance of household and similar electrical laundry appliances
• Current Stage: PPUB - Publication issued
• Start Date: 27-Mar-2012
• Completion Date: 27-Mar-2012

Standards Content (sample)

IEC 60704-2-6
Edition 3.0 2012-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
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 60704-2-6:2012
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60704-2-6
Edition 3.0 2012-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
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
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX
ICS 17.140.20; 97.060 ISBN 978-2-8322-0063-6

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – 60704-2-6  IEC:2012
CONTENTS

FOREWORD ........................................................................................................................... 3

INTRODUCTION ..................................................................................................................... 5

1 Scope and object .............................................................................................................. 6

1.1 Scope ...................................................................................................................... 6

1.2 Object ..................................................................................................................... 6

1.3 Measurement uncertainty ........................................................................................ 6

2 Normative references ....................................................................................................... 7

3 Terms and definitions ....................................................................................................... 7

4 Measurement methods and acoustical environments ........................................................ 8

4.2 Direct method .......................................................................................................... 8

4.3 Comparison method ................................................................................................ 8

5 Instrumentation ................................................................................................................ 8

6 Operation and location of appliances under test ............................................................... 8

6.1 Equipping and pre-conditioning of appliances ....................................................... 8

6.2 Supply of electric energy and of water or gas ....................................................... 9

6.3 Climatic conditions ............................................................................................... 9

6.4 Loading and operating of appliances during tests ................................................. 9

6.5 Location and mounting of appliances .................................................................. 10

6.101 Standard test programme for noise measurements ............................................. 10

6.102 Standard test load for noise measurements ........................................................ 11

7 Measurement of sound pressure levels ........................................................................... 12

7.1 Microphone array, measurement surface and RSS location for essentially

free-field conditions over reflecting plane(s) .......................................................... 12

7.4 Measurements ....................................................................................................... 12

8 Calculation of sound pressure and sound power levels ................................................... 13

9 Information to be recorded.............................................................................................. 13

9.6 Equipment and pre-conditioning of appliance under test ........................................ 13

9.7 Electric supply, water supply, etc. ......................................................................... 13

10 Information to be reported .............................................................................................. 13

Annexes ............................................................................................................................... 15

Annex A (normative) Standard test table .............................................................................. 15

Figure 101 – Standard Exhaust ............................................................................................. 14

Table 101 – Standard deviations of sound power levels .......................................................... 7

Table 102 – Standard deviations for declaration and verification ............................................. 7

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60704-2-6  IEC:2012 – 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 International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. 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 third edition cancels and replaces the second edition published in 2003. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) it does not contain the description of an appropriate test enclosure which has been

incorporated in Part 1;

b) it clarifies that only appliances designed for front loading and specified by the

manufacturer for building-in, under a counter or placing under a worktop between cabinets

(under-counter types) shall be placed in a test enclosure.
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– 4 – 60704-2-6  IEC:2012
The text of this standard is based on the following documents:
FDIS Report on voting
59D/394/FDIS 59D/397/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 the third edition (2010) of

IEC 60704-1, Household and similar electrical appliances – Test code for the determination of

airborne acoustical noise – Part 1: General requirements.
NOTE When “Part 1” is mentioned in this standard, it refers to IEC 60704-1.

This Part 2-6 supplements or modifies the corresponding clauses in IEC 60704-1, so as to

establish the test code for tumble dryers. 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 should be adapted accordingly.

Subclauses, tables and figures that are numbered starting from 101 are additional to those in

Part 1. 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.

A list of all the parts in the IEC 60704 series, published under the general title Household and

similar electrical appliances – Test code for the determination of airborne acoustical noise,

can be found on the IEC website.

The committee has decided that the contents of this publication will remain unchanged until

the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data

related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
---------------------- Page: 6 ----------------------
60704-2-6  IEC:2012 – 5 –
INTRODUCTION

The measuring conditions specified in this part of IEC 60704 provide for sufficient accuracy in

determining the 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.

NOTE As stated in the introduction to IEC 60704-1, this test code concerns airborne noise only.

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– 6 – 60704-2-6  IEC:2012
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
Addition:

These particular requirements apply 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 worktop or under a sink, for wall-mounting or on a counter. For the purpose

of this standard, washer-dryer combinations, when operated as a dryer, are considered as a

tumble dryer.
NOTE 101 For washing function, see IEC 60704-2-4.
This standard is also applicable for gas-fired electric tumble dryers.
1.1.2 Types of noise
Replacement:

The methods specified in ISO 3743-1, ISO 3743-2 and ISO 3744 can 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 should be taken that the maximum size of the appliance

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:
---------------------- Page: 8 ----------------------
60704-2-6  IEC:2012 – 7 –

The estimated values of standard deviations of sound power levels, determined according to

this standard, are:
Table 101 – Standard deviations of sound power levels
Standard deviation
σ (repeatability) σ (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 values indicated in Table 102 apply:
Table 102 – Standard deviations for declaration and verification
Standard deviation
σ (production) σ (total) σ (reference)
P t M
0,7 to 1,0 1,1 to 1,3 1,5
2 Normative references
This clause of Part 1 is applicable except as follows:
Addition:

IEC 61121: ― , Tumble dryers for household use – Methods for measuring the performance

IEC 60456:2010, Clothes washing machines for household use – Methods for measuring the

performance

ISO 7235, Acoustics – Laboratory measurement procedures for ducted silencers and air-

terminal units – Insertion loss, flow noise and total pressure loss
3 Terms and definitions
This clause of Part 1 is applicable except as follows.
Addition:
3.101
tumble dryer

appliance in which textile material is dried by tumbling in a rotating drum, through which

heated air is passed
___________
To be published.
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– 8 – 60704-2-6  IEC:2012
3.102
rated capacity

maximum mass in kg of dry textiles of a particular defined type, which the manufacturer

declares can be treated in the tumble dryer on the programme selected. If the rated capacity

is not declared, it shall be deduced from the free inside volume of the drum, according to the

ratio 1 kg / 24 l

Note 1 to entry: The rated capacity should be the same as the one used for measuring the drying performance

and energy consumption according to IEC 61121.
3.103
cotton test load
textile load consisting of towels only, as defined in Annex B of IEC 61121:―.
4 Measurement methods and acoustical environments
This clause of Part 1 is applicable except as follows:
4.2 Direct method
Addition:

NOTE 101 If pure tone components are present in the noise emitted by the source, the estimated standard

deviation of the measured sound pressure levels in the special reverberation room may increase. In such cases

additional microphone positions or source positions may be necessary, as specified in ISO 3743-2.

4.3 Comparison method
Addition:

NOTE 101 If pure tone components are present in the noise emitted by the source, the estimated standard

deviation of the measured sound pressure levels in the hard-walled test room or in the special reverberation room

may increase. In such cases additional microphone positions or source positions may be necessary as specified in

ISO 3743-1 or ISO 3743-2.
5 Instrumentation
This clause of Part 1 is applicable.
6 Operation and location of appliances under test
This clause of Part 1 is applicable except as follows:
6.1 Equipping and pre-conditioning of appliances
6.1.1
Addition:

Prior to noise measurement, filters if any, shall be cleaned according to the manufacturer's

instructions.

If, according to the manufacturer's instructions, the tumble dryer can be connected to an

exhaust device, the standard exhaust as described in Figure 101 shall be connected. It

consists of a pipe connected to a muffler. The pipe shall be rigid with smooth inner walls and

shall have the widest diameter among those specified by the manufacturer. If not stated, a

standard pipe with the best fitting diameter shall be used. The muffler shall have an insertion

loss as specified in the table of Figure 101. It shall have a circular section with the same inner

diameter as that of the pipe, a length as specified in Figure 101 and shall not have parts

---------------------- Page: 10 ----------------------
60704-2-6  IEC:2012 – 9 –

protruding inside that may cause additional pressure drops. The pipe and the muffler shall

also comply with all the specifications reported in Figure 101 and care shall be taken that they

do not radiate noise. Horizontal, vertical or inclined mounting of the pipe and the muffler is

possible. A hose which is integrated in the appliance shall substitute the first straight pipe and

the bend of the standard exhaust. It is directly connected to the muffler.
An exhaust hose delivered by the manufacturer shall not be used.

For appliances with alternative outlets, the measurements shall be made with the appliance

connected to the outlet producing the highest sound power level.

Care shall be taken that the noise of the exhaust air does not noticeably influence the noise of

the appliance.
6.1.3
Replacement:

Prior to noise measurements, the tumble dryer shall have been operated for at least two

complete cycles. However, any load at rated capacity may be used for this operation.

6.1.4
Replacement:

Care shall be taken to be in accordance with the climatic conditions indicated in 6.3 of Part 1.

6.2 Supply of electric energy and of water or gas
6.2.2 and 6.2.3 Not applicable .
6.2.4
Addition

Gas-fired tumble dryers are operated at reference pressure with one of their reference gases according

to their appliance category (see name plate of the appliance).
6.3 Climatic conditions
Addition

Care shall be taken to meet the climatic conditions as specified over the total duration of the

standard test programme.
6.4 Loading and operating of appliances during tests
6.4.2
Replacement:

Tumble dryers are operated in the standard test programme according to 6.101, with a load

according to 6.102.
---------------------- Page: 11 ----------------------
– 10 – 60704-2-6  IEC:2012
6.4.3 Not applicable.
6.5 Location and mounting of appliances
6.5.2 Not applicable.
6.5.3
Modification:
D = 25 cm ± 1 cm
Addition:

If the air outlet is located at the rear side of the appliance, a 90° bend of the same type as the

standard exhaust system shall be used for connection of the appliance to the standard

exhaust system.

NOTE 101 The outlet of the standard exhaust may terminate at an air evacuating system or outside the test room,

in such a way that the influence on noise and pressure drop can be neglected. This is to minimise temperature and

humidity variation.
6.5.5
Addition:

Appliances designed for front loading and specified by the manufacturer for building under a

counter or for placing under a worktop between cabinets (under-counter types) shall be built-

in according to the manufacturer’s installation instructions in an appropriate test enclosure

according to Annex B of Part 1.
Addition:
6.101 Standard test programme for noise measurements

For automatic tumble dryers the standard test programme for noise measurements is a “dry

cotton” programme for achieving a final moisture content of the test load µ = 0 % ± 3 % after

completion of the programme according to the manufacturer’s instruction.

For non-automatic tumble dryers, the dryer is operated for as long as required to achieve the

final moisture content as given above.

NOTE 1 The time required is determined by monitoring the drying process. This can be done by either having the

tumble dryer placed on a platform scale or by pre-testing.

NOTE 2 Examples of operations that may occur after completion of the programme are monitoring and anti-

creasing operations.
The final moisture content of the test load is calculated as follows:
 
W −W
f 0
µ =   × 100 %
 
 0 
where

W is the mass of the standard test load after completion of the standard test programme;

W is the mass of the standard test load after conditioning, according to 6.102.2.

---------------------- Page: 12 ----------------------
60704-2-6  IEC:2012 – 11 –
6.102 Standard test load for noise measurements
6.102.1 General

The standard test load for noise measurements of tumble dryers consists of a conditioned

cotton test load at a weight close to, but in any case not more than, the rated capacity.

Immediately before each noise test run, the conditioned standard test load shall be wetted

with the initial moisture content of (60 ± 2) %.
The initial moisture content of the test load is calculated as follows:
W−W 
i 0
 
µ = × 100 %
 
 
where
W is the mass of the standard test load after wetting;

W is the mass of the standard test load after conditioning, according to 6.102.2.

NOTE Typically, the initial moisture content is obtained by using a rinse cycle of a washing machine followed only

by spin drying with an approximate speed of 1 100 rpm.

To minimize the influence of changes in the characteristics of the cotton test load items with

increasing age, the standard test load shall consist of cotton test load items which are well

distributed in age to give an average age of the standard test load between 30 and 50 runs of

the standard test programme. The number of items or average age shall not be adjusted

during a test series.
The average age of the standard test load is calculated as follows:
A = × n×a
i i
where

a is the age of a single cotton test load item expressed as the number of test runs after pre-

treatment as defined in 6.102.3;
n is the number of cotton test load items of the same age;

A is the average age of the standard test load expressed as the number of test runs.

Cotton test load items shall undergo normalisation as defined in 6.102.4, after having been

used for at least 10 runs of the standard test programme.

No test load item shall be used for more than 80 runs of the standard test programme,

excluding pre-treatment runs prior to initial use and normalisation runs.
6.102.2 Conditioning of cotton test load
6.102.2.1 General

Conditioning is the process of bringing the cotton test load to reach specific remaining

moisture content after normalisation and drying and prior the next test series.

Conditioning may be done in an ambient controlled room/chamber or using the bone dry

method.
---------------------- Page: 13 ----------------------
– 12 – 60704-2-6  IEC:2012

NOTE The cotton test load does not have to be conditioned between consecutive runs of the standard test

programme. However, the test load should be dried in a tumble dryer until the weight is within 2 % of the initial

weight of the standard test load for noise measurements.
6.102.2.2 Conditioning in an ambient room/chamber

In this method, the cotton test load items are placed in a room/chamber with ambient

temperature and humidity as defined in 6.3 of Part 1. Two options are available as follows:

• the cotton test load items shall be hung singly and separately so that air can freely

circulate between individual load items. The load is left for a period of not less than 15 h;

• the cotton test load items shall be left until their mass has changed by less than 0,5 % for

two successive measurements which are taken at intervals of 2 h or more.
6.102.2.3 Conditioning using bone dry method

In this method, the cotton test load items are dried in a tumble dryer of known performance

until the remaining moisture content has been
...