ISO 15042:2017

INTERNATIONAL ISO
STANDARD 15042
Second edition
2017-07
Multiple split-system air conditioners
and air-to-air heat pumps — Testing
and rating for performance
Climatiseurs et pompes à chaleur air/air multi-split — Essais et
détermination des caractéristiques de performance
Reference number
ISO 15042:2017(E)
©
ISO 2017

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ISO 15042:2017(E)

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© ISO 2017, Published in Switzerland
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ISO 15042:2017(E)

Contents Page
Foreword .vi
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Symbols . 5
5 Airflow setting . 8
5.1 General . 8
5.2 Airflow setting for ducted indoor units . 8
5.2.1 General. 8
5.2.2 Airflow setting procedure for ducted indoor units . 8
5.3 ESP for rating . 8
5.4 Airflow setting for non-ducted indoor units measured by air enthalpy method .10
5.5 Outdoor airflow .10
5.6 Unit supplied without indoor fan.10
6 Cooling tests .10
6.1 Cooling capacity test .10
6.1.1 General conditions .10
6.1.2 Temperature conditions .11
6.1.3 Test conditions.12
6.2 Maximum cooling performance test.13
6.2.1 General conditions .13
6.2.2 Temperature conditions .13
6.2.3 Airflow conditions .13
6.2.4 Test conditions.13
6.2.5 Performance requirements .13
6.3 Minimum cooling test .15
6.3.1 General conditions .15
6.3.2 Temperature conditions .15
6.3.3 Airflow conditions .15
6.3.4 Test condition .15
6.3.5 Performance requirements .16
6.4 Freeze-up drip test (applies to non-ducted multi-splits) .16
6.4.1 General conditions .16
6.4.2 Temperature conditions .16
6.4.3 Airflow conditions .16
6.4.4 Test conditions.17
6.4.5 Performance requirements .17
6.5 Condensate control test and enclosure sweat test .17
6.5.1 General conditions .17
6.5.2 Temperature conditions .17
6.5.3 Airflow conditions .17
6.5.4 Test conditions.18
6.5.5 Performance requirements .18
7 Heating tests.18
7.1 Heating capacity tests .18
7.1.1 General conditions .18
7.1.2 Temperature conditions .19
7.1.3 Airflow conditions .20
7.1.4 Defrost operation .20
7.1.5 Test procedure — General .21
7.1.6 Preconditioning period .21
7.1.7 Equilibrium period . . .21
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ISO 15042:2017(E)

7.1.8 Data collection period .21
7.1.9 Test procedure when a defrost cycle (whether automatically or manually
initiated) ends the preconditioning period (7.1.6) .22
7.1.10 Test procedure when a defrost cycle does not end the preconditioning
period (7.1.6) .22
7.1.11 Test procedure for transient tests .23
7.1.12 Heating capacity test results . .24
7.2 Maximum heating performance test .24
7.2.1 General conditions .24
7.2.2 Temperature conditions .24
7.2.3 Airflow conditions .25
7.2.4 Test conditions.25
7.2.5 Performance requirements .25
7.3 Minimum heating performance test .25
7.3.1 General conditions .25
7.3.2 Temperature conditions .25
7.3.3 Airflow conditions .26
7.3.4 Test conditions.26
7.3.5 Performance requirements .26
7.4 Automatic defrost performance test .26
7.4.1 General conditions .26
7.4.2 Temperature conditions .27
7.4.3 Airflow conditions .27
7.4.4 Test conditions.27
7.4.5 Performance requirements .27
8 Heat recovery test .27
8.1 Heat recovery capacity ratings .27
8.1.1 General conditions .27
8.1.2 Temperature conditions .27
9 Test methods and uncertainties of measurement .28
9.1 Test methods .28
9.1.1 General.28
9.1.2 Calorimeter test method .28
9.1.3 Indoor air enthalpy method .28
9.1.4 Capacity tests .29
9.2 Uncertainty of measurement .29
9.3 Test tolerances for the capacity tests .30
9.4 Test tolerances for performance tests .31
10 Test results .31
10.1 Capacity results .31
10.1.1 General.31
10.1.2 Adjustments .32
10.1.3 Cooling capacity calculations .32
10.1.4 Heating capacity calculations .32
10.1.5 Power input of fans .33
10.2 Data to be recorded .33
10.3 Test report .36
10.3.1 General information .36
10.3.2 Rating test results .36
10.3.3 Performance tests .36
11 Marking provisions .37
11.1 Nameplate requirements .37
11.2 Nameplate information .37
11.3 Split systems .37
12 Publication of ratings .38
12.1 Standard ratings .38
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ISO 15042:2017(E)

12.2 Other ratings .38
Annex A (normative) Airflow settings for ducted units .39
Annex B (normative) Test requirements .44
Annex C (informative) Airflow measurement .51
Annex D (normative) Calorimeter test method .57
Annex E (normative) Indoor air enthalpy test method .65
Annex F (informative) Part-load capacity tests and determination of energy efficiency
ratios and coefficients of performance .72
Annex G (informative) Individual indoor unit capacity tests .73
Annex H (normative) Heat recovery test method .75
Annex I (informative) Refrigerant enthalpy test method .76
Annex J (informative) Outdoor air enthalpy test method .78
Annex K (informative) Indoor calorimeter confirmative test method .81
Annex L (informative) Outdoor calorimeter confirmative test method .83
Annex M (informative) Balanced-type calorimeter confirmative test method .85
Annex N (informative) Cooling condensate measurements .86
Annex O (normative) Supplemental requirements when rating fan-less (coil only) type units .87
Annex P (informative) Pictorial examples of the heating capacity test procedures given in 7.1 .90
Bibliography .97
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ISO 15042:2017(E)

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
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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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 86, Refrigeration and air-conditioning,
Subcommittee SC 6, Testing and rating of air-conditioners and heat pumps.
This second edition cancels and replaces the first edition (ISO 15042:2011), which has been technically
revised.
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INTERNATIONAL STANDARD ISO 15042:2017(E)
Multiple split-system air conditioners and air-to-air heat
pumps — Testing and rating for performance
1 Scope
This document specifies the performance testing, the standard conditions and the test methods for
determining the capacity and efficiency ratings of air-cooled air conditioners and air-to-air heat pumps.
This document is applicable to the following equipment:
― basic multi-split systems, modular multi-split systems and modular heat recovery multi-split
systems. These multi-split systems include air-to-air systems with non-ducted and/or ducted
indoor units with integral fans and indoor units supplied without fans.
This document is limited to:
― residential, commercial and industrial split-system air conditioners and heat pumps;
― factory-made, electrically driven and use mechanical compression;
― single- and multiple-circuit split-systems which utilize one or more compressors with no more
than two steps of control of the outdoor unit;
or
― split-systems with a single refrigeration circuit which utilize one or more variable-speed
compressors or alternative compressor combinations for varying the capacity of the system by
three or more steps.
These split-systems are designed to operate with a combination of one or more outdoor units and
two or more indoor units designed for individual operation, and such modular systems are capable of
transferring recovered heat from one or more indoor units to other units in the same system.
The requirements of testing and rating contained in this document are based on the use of matched
assemblies.
This document is not applicable to the rating and testing of the following:
a) water-cooled or water source equipment;
b) mobile (single-duct) units having a condenser exhaust duct;
c) individual assemblies not constituting a complete refrigeration system;
d) equipment using the absorption refrigeration cycle.
e) ducted air conditioners and/or ducted heat pumps, rated at less than 8 kW and intended to operate
at external static pressures of less than 25 Pa, controlled by a single thermostat/controller (refer to
ISO 5151);
f) multiple split-system utilizing one or more refrigeration systems, one outdoor unit and one or more
indoor units, controlled by a single thermostat/controller (refer to ISO 5151 or ISO 13253).
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ISO 15042:2017(E)

This document does not cover the determination of seasonal efficiencies or seasonal part-load
performances, which can be required in some countries because they provide a better indication of
efficiency under actual operating conditions.
NOTE Throughout this document, the terms “equipment” and “systems” mean “multi-split air conditioners”
and/or “multi-split heat pumps”.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 817, Refrigerants — Designation and safety classification
ISO 5151, Non-ducted air conditioners and heat pumps — Testing and rating for performance
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
me a s ur ement (GUM: 1995)
3 Terms and definitions
For the purposes of this document, the following definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available
...