IEC 61121:2002

INTERNATIONAL IEC
STANDARD
Third edition
2002-07
Tumble dryers for household use –
Methods for measuring the performance
Sèche-linge à tambour à usage domestique –
Méthodes de mesure de l'aptitude à la fonction
Reference number
Publication numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.
Consolidated editions
The IEC is now publishing consolidated versions of its publications. For example,
edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the
base publication incorporating amendment 1 and the base publication incorporating
amendments 1 and 2.
Further information on IEC publications
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology. Information relating to
this publication, including its validity, is available in the IEC Catalogue of
publications (see below) in addition to new editions, amendments and corrigenda.
Information on the subjects under consideration and work in progress undertaken
by the technical committee which has prepared this publication, as well as the list
of publications issued, is also available from the following:
• IEC Web Site (www.iec.ch)
• Catalogue of IEC publications
The on-line catalogue on the IEC web site (www.iec.ch/catlg-e.htm) enables
you to search by a variety of criteria including text searches, technical
committees and date of publication. On-line information is also available on
recently issued publications, withdrawn and replaced publications, as well as
corrigenda.
• IEC Just Published
This summary of recently issued publications (www.iec.ch/JP.htm) is also
available by email. Please contact the Customer Service Centre (see below) for
further information.
• Customer Service Centre
If you have any questions regarding this publication or need further assistance,
please contact the Customer Service Centre:
Email: custserv@iec.ch
Tel: +41 22 919 02 11
Fax: +41 22 919 03 00
INTERNATIONAL IEC
STANDARD
Third edition
2002-07
Tumble dryers for household use –
Methods for measuring the performance
Sèche–linge à tambour à usage domestique –
Méthodes de mesure de l'aptitude à la fonction
 IEC 2002  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.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch  Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale
U
International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 61121  IEC:2002(E)
CONTENTS
FOREWORD . 3
INTRODUCTION .5
1 Scope . 6
2 Normative references. 6
3 Definitions and symbols . 6
4 Dimension. 8
5 Rated capacity .9
6 General conditions for measurements . 9
6.1 General . 9
6.2 Resources and ambient conditions . 9
7 Test loads.10
7.1 Composition.10
7.2 Usage.11
7.3 Preparation.12
8 Instrumentation and accuracy.13
8.1 Mass.13
8.2 Water and air temperature .13
8.3 Water volume .13
8.4 Water pressure .13
8.5 Water hardness .13
8.6 Water conductivity .13
8.7 Electrical energy .13
8.8 Time .13
8.9 Ambient humidity .13
9 Performance tests.14
9.1 General .14
9.2 Procedure for drying performance .14
10 Evaluation and calculation.16
10.1 Final moisture content of the load.16
10.2 Electric energy consumption .16
10.3 Water consumption .17
10.4 Time .17
10.5 Condensation efficiency .17
10.6 Evenness of drying.17
11 Reporting of test results .18
Annex A (normative) Nominal and standard exhaust duct for tumble dryer testing .19
Annex B (normative) Cotton test load.22
Annex C (normative) The bone-dry method.24
Annex D (normative) Water preparation .25
Bibliography .26

61121  IEC:2002(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
TUMBLE DRYERS FOR HOUSEHOLD USE –
METHODS FOR MEASURING THE PERFORMANCE
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 61121 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 1997, of which it
constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
59D/219/FDIS 59D/222/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.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
Annexes A, B, C and D form an integral part of this standard.
In this standard, the following print types are used:
– test specifications: in italic type;
– notes: in small roman type;
– other text: in roman type.
Words in bold in the text are defined in clause 3.

– 4 – 61121  IEC:2002(E)
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.
The contents of the corrigendum of April 2003 and September 2003 have been included in
this copy.
61121  IEC:2002(E) – 5 –
INTRODUCTION
This third edition has been developed in light of experience with use of the second edition of
IEC 61121. Other changes include some minor revisions to the test conditions and alterations
to the test load to ensure that this remains harmonised with the IEC 60456 load for clothes
washers.
In summary, the main changes are as follows.
1) General:
– more terms have been defined and some previous definitions have been streamlined, in
addition to the correction of some symbols and equations;
– where possible, definitions and terms have been used in common with IEC 60456;
– the content has been organised into a more logical and simple structure, and repetitive
sections have been removed.
2) The conditions of measurement:
– the wording of various sections has been revised to reduce ambiguity;
– limits have been defined for water conductivity for auto-sensing dryers that are sensitive
to conductivity, as well as methods to adjust conductivity where necessary;
– specifications of a nominal exhaust duct were included.
3) Reproducibility and repeatability of test results:
– revision of the specification for the cotton test load to include suitable test materials
which are currently available on the market;
– more careful definition of the process and conditions for pre-treatment, conditioning
and normalisation.
4) Test methods:
– accuracy of measurement has been defined for all instruments;
– limits and interpretations of the allowable final moisture content for each type of dryer
are now defined;
– practical advice regarding the test procedure has been given with the aim of reducing
ambiguity.
– 6 – 61121  IEC:2002(E)
TUMBLE DRYERS FOR HOUSEHOLD USE –
METHODS FOR MEASURING THE PERFORMANCE
1 Scope
This International Standard is applicable to household electric tumble dryers of the automatic
and non-automatic type, with or without a cold water supply and incorporating a heating device.
The object is to state and define the principal performance characteristics of household electric
tumble dryers of interest to users and to describe standard methods for measuring these
characteristics.
This standard is concerned neither with safety nor with performance requirements.
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.
IEC 60456, Clothes washing machines for household use – Methods for measuring the
performance
IEC 60734, Hard water to be used for testing the performance of some household electrical
appliance
IEC 61036, Alternating current static watt-hour meters for active energy (Classes 1 and 2)
IEC 61591:1997, Household range hoods – Methods for measuring performance
ISO 5167-1, Measurement of fluid flow by means of pressure differential devices – Part 1:
Orifice plates, nozzles and Venturi tubes inserted in circular cross-section conduits running full
3 Definitions and symbols
For the purposes of this standard, the following definitions apply.
3.1
tumble dryer
appliance in which textile material is dried by tumbling in a rotating drum, through which heated
air is passed
3.2
air vented tumble dryer
tumble dryer with a fresh-air intake which is heated and passed over the textile material and
where the resulting moist air is exhausted into the room or vented outside
3.3
condenser tumble dryer
tumble dryer in which the air used for the drying process is dehumidified by cooling
NOTE Combinations of the above-mentioned types are possible.

61121  IEC:2002(E) – 7 –
3.4
automatic tumble dryer
tumble dryer which switches off the drying process when a certain moisture content of the
load is reached
NOTE This may include conductivity or temperature sensing
3.5
non-automatic tumble dryer
tumble dryer which does not switch off the drying process when a certain moisture content of
the load is reached, usually controlled by a timer, but may also be manually controlled
3.6
pre-treatment
successive washing, rinsing, spinning and drying of a new test load prior to its first use to avoid
rapid changes of characteristics during the tests
3.7
normalisation
successive washing, rinsing, spinning and drying of a test load after a pre-determined number
of cycles to bring the test load to a normal state
3.8
conditioning
treatment of test load to assure homogenous condition
3.9
programme
series of operations which are pre-defined and which are declared as suitable for drying certain
types of textiles
3.10
cycle
complete drying process, as defined by the programme selected, consisting of a series of
different operations (heat, cool down etc.)
3.11
rated capacity
mass in kg of dry textiles of a particular defined type, which the manufacturer declares can be
treated in a specific programme

– 8 – 61121  IEC:2002(E)
3.12 List of symbols
μ actual final moisture content of the test load (%)
f
μ nominal final moisture content (%) given in table 3, without tolerances
f0
μ actual final moisture content of the test load after the i:th cycle (%)
fi
μ actual final moisture content of the j:th individual piece of textile in a cycle (%)
fj
μ actual initial moisture content (%)
i
μ μ
j arithmetic average of for all individual load items
(f, j)
μ nominal initial moisture content (%) given in table 2, without tolerances
i0
μ arithmetical average of μ for all i cycles
f
C condensation efficiency (%)
E measured energy consumption kWh
m
E corrected energy consumption kWh
L measured water consumption (l)
m
L corrected water consumption (l)
n number of cycles
s standard deviation as a measure of the variability between cycles in one test series
b
S average drying evenness
w
s standard deviation for the evenness of drying within a load
wr
W rated capacity for the programme (g)
W conditioned mass of the test load (g)
W mass of the test load after drying, "the final mass"
f
W mass of the test load after wetting (but before drying), "the initial mass"
i
W mass of the condensed water
w
t measured programme time
m
t corrected programme time
4 Dimensions
Height a = vertical dimension measured from the lower edge (on the floor) to the upper
edge of the top, with the door closed. If adjustable levelling feet are provided,
they shall be moved up and down to determine minimum and maximum possible
heights.
Height a = maximum vertical dimension measured from the lower edge (on the floor) to
a horizontal plane at the maximum height of the tumble dryer with the door
open. If adjustable levelling feet are provided, they shall be moved up and down
to determine minimum and maximum possible heights.
Width b = horizontal dimension, between the sides, as measured between two parallel
vertical planes against the sides of the tumble dryer, including all projections.
Depth c = horizontal dimension as measured from a vertical rear plane against the
tumble dryer and the most prominent part of the front, knobs and handles not
being taken into account, with the door closed.
Depth c = horizontal dimension as measured from a vertical rear plane against the
tumble dryer and the most prominent part of the front knobs and handles not
being taken into account, with the door open.
Drum volume = the volume of the drum in which textiles are placed, determined as the inside
volume of the drum, in litres, after subtraction of ribs or other inward
protrusions, etc.
61121  IEC:2002(E) – 9 –
5 Rated capacity
If the rated capacity is not declared by the manufacturer, the rated capacity shall be deduced
from the volume of the drum according to the following ratios:
– for cotton textiles: 1 kg / 24 l;
– for easy-care textiles: 1 kg / 60 l.
Where the manufacturer gives a range of values for the rated capacity for a particular textile
type, the maximum value shall be used.
NOTE For different textiles the rated capacity of an appliance may be different.
6 General conditions for measurements
6.1 General
The measurements shall be carried out on a tumble dryer installed and used in accordance
with the manufacturer's instructions, except as required by this standard.
Where the tumble dryer is intended for use without a duct (i.e. the tumble dryer is intended to
be vented into the room), the tumble dryer shall be tested as supplied without a duct.
Where the tumble dryer is intended for use with a duct and the duct is supplied with the
tumble dryer (i.e. not as a separate accessory), the tumble dryer is tested with this duct,
placed in a configuration consisting of three right angle bends as in figure A.2, as far as
possible.
Where the tumble dryer is intended for use with a duct and the duct is not supplied with the
tumble dryer, the tumble dryer shall be tested with a duct as specified in annex A.
Where a manufacturer gives the option to use the tumble dryer both with and without a duct,
the tumble dryer shall be tested without a duct.
The test report shall clearly state which duct configuration, if any, is used in each test.
6.2 Resources and ambient conditions
6.2.1 Electricity supply
The supply voltage shall be maintained at the rated voltage ±2 % throughout the test. If a
voltage range is indicated, then the supply voltage shall be the nominal voltage of the country
in which the tumble dryer is intended to be used.
The supply frequency shall be maintained at the rated frequency ±1 % throughout the test.
If a frequency range is indicated, the test frequency shall be the nominal frequency of the
country in which the tumble dryer is intended to be used.
6.2.2 Water supply
For all processes on the test load a water hardness of not higher than (2,5 ± 0,2) mmol/l shall
be used. Water hardness shall be reported. If water hardness needs to be adjusted, IEC 60734
shall be followed.
– 10 – 61121  IEC:2002(E)
The temperature of the cold water supply, if required, shall be (15 ± 2) °C. The measured water
temperature shall be reported.
The pressure of the water supply during water intake at each appliance water inlet shall
be maintained at (240 ± 50) kPa throughout the test. The measured water pressure shall be
recorded.
For testing conductivity controlled automatic tumble dryers, water with a conductivity of
(75 ± 15) mS/m at 20 °C shall be used. If the water conductivity is not within the range of this
requirement, it can be adjusted as described in annex D. The conductivity shall be reported.
6.2.3 Ambient temperature
The ambient temperature of the room in the vicinity of the dryer shall be maintained at
(20 ± 2) °C throughout the test. The measured ambient temperature shall be recorded.
6.2.4 Ambient humidity
The ambient humidity of the room in the vicinity of the dryer shall be maintained at (65 ± 5) %
throughout the test. The measured ambient humidity shall be recorded.
7 Test loads
7.1 Composition
7.1.1 Cotton test load
The cotton test load shall consist of sheets, pillowcases and hand-towels as defined in
annex B.
The test load shall be made up of conditioned items whose total mass is as close as possible
to W. This mass is recorded as conditioned mass, W .
The number of sheets, pillowcases and hand towels in the c
...

INTERNATIONAL IEC
STANDARD 61121
Edition 3.1
2005-07
Edition 3:2002 consolidated with amendment 1:2005
Tumble dryers for household use –
Methods for measuring the performance

Reference number
Publication numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.
Consolidated editions
The IEC is now publishing consolidated versions of its publications. For example,
edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the
base publication incorporating amendment 1 and the base publication incorporating
amendments 1 and 2.
Further information on IEC publications
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology. Information relating to
this publication, including its validity, is available in the IEC Catalogue of
publications (see below) in addition to new editions, amendments and corrigenda.
Information on the subjects under consideration and work in progress undertaken
by the technical committee which has prepared this publication, as well as the list
of publications issued, is also available from the following:
• IEC Web Site (www.iec.ch)
• Catalogue of IEC publications
The on-line catalogue on the IEC web site (www.iec.ch/searchpub) enables you to
search by a variety of criteria including text searches, technical committees
and date of publication. On-line information is also available on recently issued
publications, withdrawn and replaced publications, as well as corrigenda.
• IEC Just Published
This summary of recently issued publications (www.iec.ch/online_news/ justpub)
is also available by email. Please contact the Customer Service Centre (see
below) for further information.
• Customer Service Centre
If you have any questions regarding this publication or need further assistance,
please contact the Customer Service Centre:

Email: custserv@iec.ch
Tel: +41 22 919 02 11
Fax: +41 22 919 03 00
INTERNATIONAL IEC
STANDARD 61121
Edition 3.1
2005-07
Edition 3:2002 consolidated with amendment 1:2005
Tumble dryers for household use –
Methods for measuring the performance

 IEC 2005  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.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch
PRICE CODE
CK
Commission Electrotechnique Internationale

International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – 61121  IEC:2002+A1:2005(E)
CONTENTS
FOREWORD.4
INTRODUCTION.6

1 Scope.7
2 Normative references.7
3 Definitions and symbols .7
4 Dimensions.9
5 Rated capacity.10
6 General conditions for measurements .10
6.1 General .10
6.2 Resources and ambient conditions.10
7 Test loads.11
7.1 Composition .11
7.2 Usage.12
7.3 Preparation.13
8 Instrumentation and accuracy .14
8.1 Mass .14
8.2 Water and air temperature .14
8.3 Water volume .14
8.4 Water pressure.14
8.5 Water hardness .14
8.6 Water conductivity .14
8.7 Electrical energy.14
8.8 Time.14
8.9 Ambient humidity .15
9 Performance tests .15
9.1 General .15
9.2 Procedure for drying performance.15
10 Evaluation and calculation.17
10.1 Final moisture content of the load .17
10.2 Electric energy consumption .18
10.3 Water consumption.18
10.4 Time.18
10.5 Condensation efficiency.18
10.6 Evenness of drying .19
11 Reporting of test results.19

Annex A (normative) Nominal and standard exhaust duct for tumble dryer testing.20
Annex B (normative) Cotton test load .23
Annex C (normative) The bone-dry method .25
Annex D (normative) Water preparation .26

61121  IEC:2002+A1:2005(E) – 3 –
Bibliography .27

Figure A.1 – Pressure/air flow curve .20
Figure A.2 – Standard exhaust .21
Figure A.3 – Standard exhaust simulator .22

Table 1 – Number of items of cotton test load for various rated capacities, W .12
Table 2 – Specifications for initial moisture content of the test load.14
Table 3 – Specification for final moisture content of the test load after drying.15

– 4 – 61121 © IEC:2002+A1:2005(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
TUMBLE DRYERS FOR HOUSEHOLD USE –
METHODS FOR MEASURING THE PERFORMANCE

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
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). 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. 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 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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 61121 has been prepared by subcommittee 59D: Home laundry
appliances, of IEC technical committee 59: Performance of household electrical appliances.
This consolidated version of IEC 61121 consists of the third edition (2002) [documents
59D/219/FDIS and 59D/222/RVD], its amendment 1 (2005) [documents 59D/286/FDIS and
59D/296/RVD] and its corrigenda of April 2003 and September 2003.
The technical content is therefore identical to the base edition and its amendment and has
been prepared for user convenience.
It bears the edition number 3.1.
A vertical line in the margin shows where the base publication has been modified by
amendment 1.
The French version of this standard has not been voted upon.

61121  IEC:2002+A1:2005(E) – 5 –
Annexes A, B, C and D form an integral part of this standard.
In this standard, the following print types are used:
– test specifications: in italic type;
– notes: in small roman type;
– other text: in roman type.
Words in bold in the text are defined in clause 3.
The committee has decided that the contents of the base publication and its amendments will
remain unchanged until the maintenance result 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.
– 6 – 61121  IEC:2002+A1:2005(E)
INTRODUCTION
This third edition has been developed in light of experience with use of the second edition of
IEC 61121. Other changes include some minor revisions to the test conditions and alterations
to the test load to ensure that this remains harmonised with the IEC 60456 load for clothes
washers.
In summary, the main changes are as follows.
1) General:
– more terms have been defined and some previous definitions have been streamlined, in
addition to the correction of some symbols and equations;
– where possible, definitions and terms have been used in common with IEC 60456;
– the content has been organised into a more logical and simple structure, and repetitive
sections have been removed.
2) The conditions of measurement:
– the wording of various sections has been revised to reduce ambiguity;
– limits have been defined for water conductivity for auto-sensing dryers that are sensitive
to conductivity, as well as methods to adjust conductivity where necessary;
– specifications of a nominal exhaust duct were included.
3) Reproducibility and repeatability of test results:
– revision of the specification for the cotton test load to include suitable test materials
which are currently available on the market;
– more careful definition of the process and conditions for pre-treatment, conditioning
and normalisation.
4) Test methods:
– accuracy of measurement has been defined for all instruments;
– limits and interpretations of the allowable final moisture content for each type of dryer
are now defined;
– practical advice regarding the test procedure has been given with the aim of reducing
ambiguity.
61121  IEC:2002+A1:2005(E) – 7 –
TUMBLE DRYERS FOR HOUSEHOLD USE –
METHODS FOR MEASURING THE PERFORMANCE

1 Scope
This International Standard is applicable to household electric tumble dryers of the automatic
and non-automatic type, with or without a cold water supply and incorporating a heating device.
The object is to state and define the principal performance characteristics of household electric
tumble dryers of interest to users and to describe standard methods for measuring these
characteristics.
This standard is concerned neither with safety nor with performance requirements.
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.
IEC 60456, Clothes washing machines for household use – Methods for measuring the
performance
IEC 60734, Hard water to be used for testing the performance of some household electrical
appliance
IEC 61036, Alternating current static watt-hour meters for active energy (Classes 1 and 2)
IEC 61591:1997, Household range hoods – Methods for measuring performance
ISO 5167-1, Measurement of fluid flow by means of pressure differential devices – Part 1:
Orifice plates, nozzles and Venturi tubes inserted in circular cross-section conduits running full
3 Definitions and symbols
For the purposes of this standard, the following definitions apply.
3.1
tumble dryer
appliance in which textile material is dried by tumbling in a rotating drum, through which heated
air is passed
3.2
air vented tumble dryer
tumble dryer with a fresh-air intake which is heated and passed over the textile material and
where the resulting moist air is exhausted into the room or vented outside

– 8 – 61121  IEC:2002+A1:2005(E)
3.3
condenser tumble dryer
tumble dryer in which the air used for the drying process is dehumidified by cooling
NOTE Combinations of the above-mentioned types are possible.
3.4
automatic tumble dryer
tumble dryer which switches off the drying process when a certain moisture content of the
load is reached
NOTE This may include conductivity or temperature sensing
3.5
non-automatic tumble dryer
tumble dryer which does not switch off the drying process when a certain moisture content of
the load is reached, usually controlled by a timer, but may also be manually controlled
3.6
pre-treatment
successive washing, rinsing, spinning and drying of a new test load prior to its first use to avoid
rapid changes of characteristics during the tests
3.7
normalisation
successive washing, rinsing, spinning and drying of a test load after a pre-determined number
of cycles to bring the test load to a normal state
3.8
conditioning
treatment of test load to assure homogenous condition
3.9
programme
series of operations which are pre-defined and which are declared as suitable for drying certain
types of textiles
3.10
cycle
complete drying process, as defined by the programme selected, consisting of a series of
different operations (heat, cool down etc.)
3.11
rated capacity
mass in kg of dry textiles of a particular defined type, which the manufacturer declares can be
treated in a specific programme

61121  IEC:2002+A1:2005(E) – 9 –
3.12 List of symbols
µ actual final moisture content of the test load (%)

f
µ nominal final moisture content (%) given in table 3, without tolerances
f0
µ actual final moisture content of the test load after the i:th cycle (%)
fi
µ actual final moisture content of the j:th individual piece of textile in a cycle (%)
fj
µ actual initial moisture content (%)
i
µ µ
j arithmetic average of for all individual load items
(f, j)
µ nominal initial moisture content (%) given in table 2, without tolerances
i0
µ arithmetical average of µ for all i cycles
f
C condensation efficiency (%)
E measured energy consumption kWh
m
E corrected energy consumption kWh
L measured water consumption (l)
m
L corrected water consumption (l)
n number of cycles
standard deviation as a measure of the variability between cycles in one test series
s
b
S average drying evenness
w
s  standard deviation for the evenness of drying within a load
wr
W rated capacity for the programme (g)
W conditioned mass of the test load (g)
W mass of the test load after drying, "the final mass"
f
W mass of the test load after wetting (but before drying), "the initial mass"
i
W mass of the condensed water
w
t measured programme time
m
t corrected programme time
4 Dimensions
Height a = vertical dimension measured from the lower edge (on the floor) to the upper
edge of the top, with the door closed. If adjustable levelling feet are provided,
they shall be moved up and down to determine minimum and maximum possible
heights.
Height a = maximum vertical dimension measured from the lower edge (on the floor) to
a horizontal plane at the maximum height of the tumble dryer with the door
open. If adjustable levelling feet are provided, they shall be moved up and down
to determine minimum and maximum possible heights.
Width b = horizontal dimension, between the sides, as measured between two parallel
vertical planes against the sides of the tumble dryer, including all projections.
Depth c = horizontal dimension as measured from a vertical rear plane against the
tumble dryer and the most prominent part of the front, knobs and handles not
being taken into account, with the door closed.
= horizontal dimension as measured from a vertical rear plane against the
Depth c
tumble dryer and the most prominent part of the front knobs and handles not
being taken into account, with the door open.
Drum volume = the volume of the drum in which textiles are placed, determined as the inside
volume of the drum, in litres, after subtraction of ribs or other inward
protrusions, etc.
– 10 – 61121  IEC:2002+A1:2005(E)
5 Rated capacity
If the rated capacity is not declared by the manufacturer, the rated capacity shall be deduced
from the volume of the drum according to the following ratios:
– for cotton textiles: 1 kg / 24 l;
– for easy-care textiles: 1 kg / 60 l.
Where the manufacturer gives a range of values for the rated capacity for a particular textile
type, the maximum value shall be used.
NOTE For different textiles the rated capacity of an appliance may be different.
6 General conditions for measurements
6.1 General
The measurements shall be carried out on a tumble dryer installed and used in accordance
with the manufacturer's instructions, except as required by this standard.
Where the tumble dryer is intended for use without a duct (i.e. the tumble dryer is intended to
be vented into the room), the tumble dryer shall be tested as supplied without a duct.
Where the tumble dryer is intended for use with a duct and the duct is supplied with the
tumble dryer (i.e. not as a separate accessory), the tumble dryer is tested with this duct,
placed in a configuration consisting of three right angle bends as in figure A.2, as far as
possible.
Where the tumble dryer is intended for use with a duct and the duct is not supplied with the
tumble dryer, the tumble dryer shall be tested with a duct as specified in annex A.
Where a manufacturer gives the option to use the tumble dryer both with and without a duct,
the tumble dryer shall be tested without a duct.
The test report shall clearly state which duct configuration, if any, is used in each test.
6.2 Resources and ambient conditions
6.2.1 Electricity supply
The supply voltage shall be maintained at the rated voltage ±2 % throughout the test. If a
voltage range is indicated, then the supply voltage shall be the nominal voltage of the country
in which the tumble dryer is intended to be used.
The supply frequency shall be maintained at the rated frequency ±1 % throughout the test.
If a frequency range is indicated, the test frequency shall be the nominal frequency of the
country in which the tumble dryer is intended to be used.

61121  IEC:2002+A1:2005(E) – 11 –
6.2.2 Water supply
For all processes on the test load a water hardness of not higher than (2,5 ± 0,2) mmol/l shall
be used. Water hardness shall be reported. If water hardness needs to be adjusted, IEC 60734
shall be followed.
The temperature of the cold water supply, if required, shall be (15 ± 2) °C. The measured water
temperature shall be reported.
The pressure of the water supply during water intake at each appliance water inlet shall
be maintained at (240 ± 50) kPa throughout the test. The measured water pressure shall be
recorded.
For testing conductivity controlled automatic tumble dryers, water with a conductivity of
(75 ± 15) mS/m at 20 °C shall be used. If the water conductivity is not within the range of this
requirement, it can be adjusted as described in annex D. The conductivity shall be reported.
6.2.3 Ambient temperature
The ambient temperature of the room in the vicinity
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