ISO 16358-1:2013

Air-cooled air conditioners and air-to-air heat pumps — Testing and calculating methods for seasonal performance factors — Part 1: Cooling seasonal performance factor

ISO 16358-1:2013 specifies the testing and calculating methods for seasonal performance factor of equipment covered by ISO 5151, ISO 13253 and ISO 15042. ISO 16358-1:2013 also specifies the seasonal performance test conditions and the corresponding test procedures for determining the seasonal performance factor of equipment, as specified above, under mandatory test conditions and is intended for use only in marking, comparison, and certification purposes. For the purposes of ISO 16358-1:2013, the rating conditions are those specified under T1 in the reference standards above. The procedures in ISO 16358-1:2013 may be used for other temperature conditions. ISO 16358-1:2013 does not apply to the testing and rating of: water-source heat pumps or water-cooled air conditioners; portable units having a condenser exhaust duct; individual assemblies not constituting a complete refrigeration system; or equipment using the absorption refrigeration cycle.

Climatiseurs à condenseur à air et pompes à chaleur air/air — Essais et méthodes de calcul des coefficients de performance saisonniers — Partie 1: Coefficient de performance saisonnier de refroidissement (COPSR)

General Information

• Status: Published
• Publication Date: 08-Apr-2013
• ICS: 23.120 - Ventilators. Fans. Air-conditioners
• ICS: 27.080 - Heat pumps
• Technical Committee: ISO/TC 86/SC 6 - Testing and rating of air-conditioners and heat pumps
• Drafting Committee: ISO/TC 86/SC 6/WG 1 - Air-source air-conditioners and heat pumps
• Current Stage: 9093 - International Standard confirmed
• Start Date: 14-Mar-2024
• Completion Date: 13-Dec-2025

Relations

• Amended By: ISO 16358-1:2013/Amd 2:2024 - Air-cooled air conditioners and air-to-air heat pumps — Testing and calculating methods for seasonal performance factors — Part 1: Cooling seasonal performance factor — Amendment 2
• Effective Date: 16-Mar-2024
• Amended By: ISO 16358-1:2013/Amd 1:2019 - Air-cooled air conditioners and air-to-air heat pumps — Testing and calculating methods for seasonal performance factors — Part 1: Cooling seasonal performance factor — Amendment 1
• Effective Date: 26-Nov-2021

Overview

ISO 16358-1:2013 - "Air-cooled air conditioners and air-to-air heat pumps - Testing and calculating methods for seasonal performance factors - Part 1: Cooling seasonal performance factor" - defines test procedures and calculation methods to determine the cooling seasonal performance factor (CSPF) and related indices for products covered by ISO 5151, ISO 13253 and ISO 15042. It is intended for marking, comparison and certification and uses the T1 rating conditions in the referenced standards. The standard explicitly excludes water-source or water-cooled equipment, portable units with condenser exhaust ducts, individual assemblies that are not complete refrigeration systems, and absorption-cycle equipment.

Key topics and technical requirements

• Scope and applicability
  • Applies to air‑cooled air conditioners and air‑to‑air heat pumps covered by ISO 5151, ISO 13253 and ISO 15042.
  • Uses T1 rating conditions by default but allows procedures to be applied at other temperatures.
• Test methods and conditions
  • Specifies additional tests beyond referenced standards and requires instrument accuracy per ISO 5151/13253/15042.
  • Defines mandatory test conditions (Table 1) for T1 moderate climate (for example: indoor DB 27 °C / WB 19 °C; outdoor DB 35 °C / WB 24 °C as referenced).
• Performance metrics and calculations
  • Defines CSPF (ratio of annual cooling removal to energy consumed) and TCSPF (includes inactive and disconnected modes).
  • Covers defined cooling load, outdoor temperature bin distributions, and how to integrate seasonal bin hours.
  • Addresses performance across capacity types: fixed-capacity, two-stage, multi-stage and variable-capacity units.
  • Includes part load factor (PLF) and degradation coefficient (CD) to account for cyclic operation and part-load cycling (Annex C normative).
• Documentation
  • Specifies required contents of the test report and provides informative annexes for figures, TCSPF calculation (Annex B), cyclic degradation testing (Annex C), and supplementary calculation methods (Annexes D and E).

Practical applications and who uses it

• Manufacturers: to rate and declare seasonal cooling performance for product datasheets and certification.
• Independent test laboratories: to perform standardized CSPF/TCSPF testing for compliance and comparison.
• Certification bodies and regulators: to set energy labelling, minimum performance standards and compliance testing.
• HVAC designers, energy consultants, and procurement specialists: to compare system efficiency on a seasonal basis for specification and lifecycle energy assessment.
• Building owners and asset managers: to select efficient air-cooled units and estimate seasonal energy consumption.

Related standards and keywords

• Related: ISO 5151, ISO 13253, ISO 15042 (testing and rating references); Part 2 (heating) and Part 3 (annual performance) are complementary.
• SEO keywords: ISO 16358-1, CSPF, TCSPF, cooling seasonal performance factor, air‑cooled air conditioners, air‑to‑air heat pumps, seasonal performance testing, HVAC efficiency standards.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 16358-1
First edition
2013-04-15
Air-cooled air conditioners and air-
to-air heat pumps — Testing and
calculating methods for seasonal
performance factors —
Part 1:
Cooling seasonal performance factor
Climatiseurs à condenseur à air et pompes à chaleur air/air — Essais
et méthodes de calcul des coefficients de performance saisonniers —
Partie 1: Coefficient de performance saisonnier de refroidissement
(COPSR)
Reference number
©
ISO 2013
© ISO 2013
All rights reserved. Unless otherwise specified, 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’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 3
5 Tests . 5
5.1 General . 5
5.2 Test conditions . 5
5.3 Test methods . 6
6 Calculations. 7
6.1 Cooling seasonal performance factor (CSPF) and total cooling seasonal performance
factor (TCSPF) . 7
6.2 Defined cooling load . 7
6.3 Outdoor temperature bin distribution for cooling . 7
6.4 Cooling seasonal characteristics of fixed capacity units . 8
6.5 Cooling seasonal characteristics of two-stage capacity units . 9
6.6 Cooling seasonal characteristics of multi-stage capacity units .10
6.7 Cooling seasonal characteristics of variable capacity units .11
7 Test report .13
Annex A (informative) Figures .15
Annex B (informative) Calculation of total cooling seasonal performance factor (TCSPF) .19
Annex C (normative) Testing and calculation method for degradation coefficient of
cyclic operation .21
Annex D (informative) Calculating method for seasonal performance factor when setting a
specific cooling load .24
Annex E (informative) Calculating method for temperature when defined load line crosses each
capacity line .25
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 documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users of this document
and does not constitute an endorsement. Equivalent products can be used if they can be shown to lead
to the same results.
The committee responsible for this document is ISO/TC 86, Refrigeration and air-conditioning,
Subcommittee SC 6, Testing and rating of air-conditioners and heat pumps.
The parts of ISO 16358 are given below:
— Part 1: Cooling seasonal performance factor
— Part 2: Heating seasonal performance factor
— Part 3: Annual performance factor
iv © ISO 2013 – All rights reserved

INTERNATIONAL STANDARD ISO 16358-1:2013(E)
Air-cooled air conditioners and air-to-air heat
pumps — Testing and calculating methods for seasonal
performance factors —
Part 1:
Cooling seasonal performance factor
1 Scope
1.1 This part of ISO 16358 specifies the testing and calculating methods for seasonal performance
factor of equipment covered by ISO 5151, ISO 13253 and ISO 15042.
1.2 This part of ISO 16358 also specifies the seasonal performance test conditions and the corresponding
test procedures for determining the seasonal performance factor of equipment, as specified in 1.1, under
mandatory test conditions and is intended for use only in marking, comparison, and certification purposes.
For the purposes of this part of ISO 16358, the rating conditions are those specified under T1 in the reference
standards in 1.1. The procedures in this part of ISO 16358 may be used for other temperature conditions.
1.3 This part of ISO 16358 does not apply to the testing and rating of:
a) water-source heat pumps or water-cooled air conditioners;
b) portable units having a condenser exhaust duct;
c) individual assemblies not constituting a complete refrigeration system; or
d) equipment using the absorption refrigeration cycle.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 5151, Non-ducted air conditioners and heat pumps — Testing and rating for performance
ISO 13253, Ducted air-conditioners and air-to-air heat pumps — Testing and rating for performance
ISO 15042, Multiple split-system air-conditioners and air-to-air heat pumps — Testing and rating for performance
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5151, ISO 13253, ISO 15042
and the following apply.
3.1
defined cooling load, L
c
heat defined as cooling demand for a given outdoor temperature
3.2
cooling seasonal total load
CSTL
total annual amount of heat that is removed from the indoor air when the equipment is operated for
cooling in active mode
3.3
cooling seasonal energy consumption
CSEC
total annual amount of energy consumed by the equipment when it is operated for cooling in active mode
3.4
cooling seasonal performance factor
CSPF
ratio of the total annual amount of heat that the equipment can remove from the indoor air when
operated for cooling in active mode to the total annual amount of energy consumed by the equipment
during the same period
3.5
part load factor
PLF
ratio of the performance when the equipment is cyclically operated to the performance when the
equipment is continuously operated, at the same temperature and humidity conditions
3.6
degradation coefficient, C
D
coefficient that indicates efficiency loss caused by cyclic operation
3.7
fixed capacity unit
equipment which does not have possibility to change its capacity
Note 1 to entry: This definition applies to each cooling and heating operation individually.
3.8
two (2)-stage capacity unit
equipment where the capacity is varied by two steps
Note 1 to entry: This definition applies to each cooling and heating operation individually.
3.9
multi-stage capacity unit
equipment where the capacity is varied by three or four steps
Note 1 to entry: This definition applies to each cooling and heating operation individually.
3.10
variable capacity unit
equipment where the capacity is varied by five or more steps to represent continuously variable capacity
Note 1 to entry: This definition applies to each cooling and heating operation individually.
3.11
cooling full-load operation
operation with the equipment and controls configured for the maximum continuous refrigeration
capacity specified by the manufacturer and allowed by the unit controls
Note 1 to entry: Unless otherwise regulated by the automatic controls of the equipment, all indoor units and
compressors shall be functioning during the full-load operation.
2 © ISO 2013 – All rights reserved

3.12
minimum-load operation
operation of the equipment and controls at minimum continuous refrigeration capacity
Note 1 to entry: All indoor units shall be functioning during the minimum-load operation.
3.13
standard cooling full capacity
cooling capacity at T1 at full-load operating conditions
3.14
standard cooling full power input
electric power input at T1 at full-load operating conditions
3.15
standard cooling half capacity
capacity which is 50 % of cooling full capacity at T1 condition with all indoor units functioning
3.16
standard cooling half power input
electric power input when operated at 50 % of cooling full capacity at T1 condition with all indoor
units functioning
3.17
standard cooling minimum capacity
capacity at T1 condition at the minimum-load operation
3.18
standard cooling minimum power input
electric power input at T1 condition at the minimum-load operation
3.19
total cooling seasonal performance factor
TCSPF
ratio of the total annual amount of heat that the equipment can remove from the indoor air to the total annual
amount of energy consumed by the equipment, including the active, inactive and disconnected modes
3.20
active mode
mode corresponding to the hours with a cooling demand of the building and whereby the cooling
function of the unit is switched on
3.21
inactive mode
mode corresponding to the hours when the unit is not operating to meet cooling demand
Note 1 to entry: This mode may include the operation of a crankcase heater.
3.22
disconnected mode
mode corresponding to the hours when the unit is electrically disconnected from the main power supply
Note 1 to entry: Power consumption is zero.
4 Symbols
Symbol Description Unit
C cooling seasonal energy consumption (CSEC) Wh
CSE
E (t) energy efficiency ratio (EER) at continuous outdoor temperature t W/W
ER
Symbol Description Unit
E (t ) energy efficiency ratio (EER) at outdoor temperature t W/W
ER j j
E (t ) energy efficiency ratio (EER) when cooling load is equal to cooling full capacity W/W
ER, ful b
E (t ) energy efficiency ratio (EER) when cooling load is equal to cooling half capacity W/W
ER, haf c
energy efficiency ratio (EER) in variable operation between half and full capac-
E (t ) W/W
ER, hf j
ity at outdoor temperature t
j
energy efficiency ratio (EER) in variable operation between minimum and half
E (t ) W/W
ER, mh j
capacity at outdoor temperature t
j
E energy efficiency ratio (EER) when cooling load is equal to cooling minimum
ER,
W/W
(t ) capacity
min p
F cooling seasonal performance factor (CSPF) –
CSP
F (t ) part load factor (PLF) at outdoor temperature t –
PL j j
F total cooling seasonal performance factor (TCSPF) –
TCSP
L cooling seasonal total load (CSTL) Wh
CST
L (t ) defined cooling load at outdoor temperature t W
c j j
n bin hours h
j
k, p, n, m number of temperature bins –
cooling power input calculated by equation of P(t ) at continuous outdoor tem-
j
P(t) W
perature t
P(t ) cooling power input applicable to any capacity at outdoor temperature t W
j j
P (t ) cooling full power input at outdoor temperature t W
ful j j
P (35) cooling full power input at T1 temperature condition W
ful
P (29) cooling full power input at outdoor temperature 29 °C W
ful
P (t ) cooling half power input at outdoor temperature t W
haf j j
P (35) cooling half power input at T1 temperature condition W
haf
P (29) cooling half power input at outdoor temperature 29 °C W
haf
cooling power input in variable operation between half and full capacity at
P (t ) W
hf j
outdoor temperature t
j
cooling power input in second stage cyclic operation between minimum and
P (t ) W
mf j
full capacity at outdoor temperature t
j
cooling power input in variable operation between minimum and half capacity
P (t ) W
mh j
at outdoor temperature t
j
P (t ) cooling minimum power input at outdoor temperature t W
min j j
P (35) cooling minimum power input at T1 temperature condition W
min
P (29) cooling minimum power input at outdoor temperature 29 °C W
min
t general continuous outdoor temperature °C
t outdoor temperature corresponding to each temperature bin °C
j
t outdoor temperature when cooling load is equal to cooling full capacity °C
b
t outdoor temperature when cooling load is equal to cooling half capacity °C
c
t outdoor temperature when cooling load is equal to cooling minimum capacity °C
p
X(t ) ratio of load to capacity at outdoor temperature t –
j j
ratio of excess capacity over load to capacity difference between half and full
X (t ) –
hf j
capacity at outdoor temperature t
j
4 © ISO 2013 – All rights reserved

Symbol Description Unit
ratio of excess capacity over load to capacity difference between minimum and
X (t ) –
mf j
full capacity at outdoor temperature t
j
ratio of excess capacity over load to capacity difference between minimum and
X (t ) –
mh j
half capacity at outdoor temperature t
j
cooling capacity calculated by equation of ϕ(t ) at continuous outdoor tempera-
j
ϕ(t) W
ture t
ϕ(t ) cooling capacity applicable to any capacity at outdoor temperature t W
j j
ϕ (t ) cooling full capacity at outdoor temperature t W
ful j j
ϕ (35) cooling full capacity at T1 temperature condition W
ful
ϕ (29) cooling full capacity at outdoor temperature 29 °C W
ful
ϕ (t ) cooling half capacity at outdoor temperature t W
haf j j
ϕ (35) cooling half capacity at T1 temperature condition W
haf
ϕ (29) cooling half capacity at outdoor temperature 29 °C W
haf
ϕ (t ) cooling minimum capacity at outdoor temperature t W
min j j
ϕ (35) cooling minimum capacity at T1 temperature condition W
min
ϕ (29) cooling minimum capacity at outdoor temperature 29 °C W
min
5 Tests
5.1 General
These tests are additional to those in ISO 5151, ISO 13253 and ISO 15042.
The accuracy of the instruments used for tests shall conform to the test methods and uncertainties of
measurements specified in ISO 5151, ISO 13253 and ISO 15042.
5.2 Test conditions
Temperature and humidity conditions as well as default values for calculation shall be as specified in Table 1.
Table 1 — Temperature and humidity conditions and default values for cooling at T1 moderate
climate condition of ISO 5151, ISO 13253 and ISO 15042
Test Characteristics Two- Multi-
Fixed Variable Default value
stage stage
Standard cooling Full capacity ϕ (35) (W)
ful
∎ ∎ ∎ ∎ —
capacity
Full power input P (35) (W)
ful
Indoor DB 27°C
Half capacity ϕ (35) (W) ϕ (29)/1,077
haf haf
— — ○ ∎
WB 19°C
Half power input P (35) (W) P (29)/0,914
haf haf
Outdoor DB 35°C
Minimum capacity ϕ (35) (W) ϕ (29)/1,077
min min
— ○ ○ ○
WB 24°C
Minimum power input P (35) (W) P (29)/0,914
min min
∎  required test.
○  optional test.
NOTE 1 If the minimum capacity test is measured, min(29) test is conducted first. Min(35) test may be measured or may be
calculated by using default value.
NOTE 2 Voltage(s) and frequency(ies) are as given in the three referenced standards.
Table 1 (continued)
Test Characteristics Two- Multi-
Fixed Variable Default value
stage stage
Low temperature Full capacity ϕ (29) (W) 1,077 × ϕ (35)
ful ful
∎ ∎ ∎ —
cooling capacity
Full power input P (29) (W) 0,914 × P (35)
ful ful
Indoor DB 27°C
Half capacity ϕ (29) (W) 1,077 × ϕ (35)
haf haf
— — ∎ ○
WB 19°C
Half power input P (29) (W) 0,914 × P (35)
haf haf
Outdoor DB 29°C
Minimum capacity ϕ (29) (W)
min
— ∎ ○ ○ —
WB 19°C
Minimum power input P (29) (W)
min
Low humidity and Degradation Full capacity ○ — — — 0,25
cyclic cooling coefficient C
D
Half capacity — — ○ — 0,25
Indoor DB 27°C
Minimum capacity
WB 16°C or lower
— ○ ○ — 0,25
Outdoor DB 29°C
WB -
∎  required test.
○  optional test.
NOTE 1 If the minimum capacity test is measured, min(29) test is conducted first. Min(35) test may be measured or may be
calculated by using default value.
NOTE 2 Voltage(s) and frequency(ies) are as given in the three referenced standards.
5.3 Test methods
5.3.1 Standard cooling capacity tests
The standard cooling capacity tests shall be conducted in accordance with Annex A of ISO 5151 and
Annex B of ISO 13253 and ISO 15042. The cooling capacity and effective power input shall be measured
during the standard cooling capacity tests.
The half capacity test shall be conducted at 50 % of full load operation. The test tolerance shall be ± 5 %
of full load capacity for continuously variable equipment. For multi-stage equipment, if 50 % capacity is
not achievable, then the tests shall be conducted at the next step above 50 %.
The minimum capacity test shall be conducted at the lowest capacity control setting which allows
steady-state operation of the equipment at the given test conditions.
If the minimum capacity tests are conducted, but if the required uncertainty of measurement specified
in ISO 5151, ISO 13253 and ISO 15042 cannot be achieved, the alternative method of calculation shall be
used. (Refer to 6.6.4 and 6.7.4.)
The manufacturer shall provide information on how to set the capacity if requested by the testing
laboratories.
5.3.2 Low temperature cooling capacity tests
The low temperature cooling capacity test shall be conducted in accordance with Annex A of ISO 5151
and Annex B of ISO 13253 and ISO 15042. If the test is not conducted, default values as given in Table 1
shall be used.
The half capacity test shall be conducted at 50 % of full load operation. The test tolerance shall be ± 5 %
of full load capacity for continuously variable equipment. For multi-stage equipment, if 50 % capacity is
not achievable, then the tests shall be conducted at the next step above 50 %.
The minimum capacity test shall be conducted at the lowest capacity control setting which allows
steady-state operation of the equipment at the given test conditions.
6 © ISO 2013 – All rights reserved

If the minimum capacity tests are conducted, but if the required uncertainty of measurement specified
in ISO 5151, ISO 13253 and ISO 15042 cannot be achieved, the alternative method of calculation shall be
used. (Refer to 6.6.4 and 6.7.4.)
The manufacturer shall provide information on how to set the capacity if requested by the testing
laboratories.
5.3.3 Low humidity cooling test and cyclic cooling test
The low humidity cooling test and cyclic cooling test shall be conducted in accordance with Annex C. If
the test is not conducted, default values as given in Table 1 shall be used.
6 Calculations
6.1 Cooling seasonal performance factor (CSPF) and total cooling seasonal perfor-
mance factor (TCSPF)
The cooling seasonal performance factor (CSPF), F , of the equipment shall be calculated by Formula (1).
CSP
L
CST
F = (1)
CSP
C
CSE
In case of calculating the total cooling seasonal performance factor (TCSPF), refer to Annex B.
6.2 Defined cooling load
The defined cooling load shall be represented by a value and the assumption that it is linearly changing
depending on the change in outdoor temperature.
Defined cooling load which shall be used is shown in Table 2.
Table 2 — Defined cooling load
Parameter Load zero (0) Load 100 %
Cooling load (W) 0 ϕ (t )
ful 100
Temperature (°C) t t
0 100
where t is the outdoor temperature at 100 % load and t is the outdoor temperature at 0 % load.
100 0
Reference values of defined cooling load to be used shall be as follows:
t = 20 °C and t = 35 °C
0 100
In case of setting other cooling load, refer to the setting method as described in Annex D.
Defined cooling load L (t ) at outdoor temperature t , which is necessary to calculate the cooling seasonal
c j j
energy consumption, shall be determined by Formula (2).
tt−
j 0
Lt()=×φ ()t (2)
cfj ul 100
tt−
100 0
where ϕ (t ) is the cooling capacity at t at full-load operating conditions.
ful 100 100
6.3 Outdoor temperature bin distribution for cooling
Table 3 shows the reference outdoor temperature bin distribution.
Cooling seasonal performance factor (CSPF) shall be calculated at the reference climate condition in Table 3.
The calculation of cooling seasonal performance factor may also be done for other climate conditions.
Table 3 — Reference outdoor temperature bin distribution
Bin number j 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Total
Outdoor tempera-
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 —
ture t °C
j
Fractional bin hours 0,055 0,076 0,091 0,108 0,116 0,118 0,116 0,100 0,083 0,066 0,041 0,019 0,006 0,003 0,002
Bin hours n n n n n n n n n n n n n n n n —
j 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Reference bin hours
100 139 165 196 210 215 210 181 150 120 75 35 11 6 4 1 817
(n ) h
j
Bin hours of each outdoor temperature may be calculated by multiplying the fractional bin hours by the
total annual cooling hours if the fractional bin hours are applicable.
In case of setting other outdoor temperature bin distribution, refer to the setting method as described
in Annex D.
6.4 Cooling seasonal characteristics of fixed capacity units
Operational performance at each test, which is used for calculation of seasonal performance factor, shall
be in accordance with Table 1.
6.4.1 Capacity characteristics against outdoor temperature
Capacity ϕ (t ) (W) of the equipment when it is operated for cooling at outdoor temperature t linearly
ful j j
changes depending on outdoor temperatures as shown in Figure A.1 in Annex A, and it is determined by
Formula (3) from two characteristics, one at 35 °C and the other at 29 °C.
φφ()29 − ()35
fulful
φφ()tt=+()35 ×−()35 (3)
fulfj ul j
35−29
6.4.2 Power input characteristics against outdoor temperature
Power input P (t ) (W) of the equipment when it is operated for cooling at outdoor temperature t
ful j j
linearly changes depending on outdoor temperatures as shown in Figure A.1 in Annex A, and it is
determined by Formula (4) from two characteristics, one at 35 °C and the other at 29 °C.
PP()29 − ()35
fulful
Pt()=+P ()35 ×−()35 t (4)
fulj ful j
35−29
6.4.3 Calculation of cooling seasonal total load (CSTL)
Cooling seasonal total load (CSTL), L , shall be determined using Formula (5) from the total sum of
CST
cooling load at each outdoor temperature t multiplied by bin hours n .
j j
m n
LL=×()tn +×φ ()tn (5)
CSTc∑∑jj fulj j
jj==11m+
a) In the range of L (t ) ≤ ϕ (t ) (j = 1 to m):
c j ful j
L (t ) shall be calculated by Formula (2).
c j
b) In the range of L (t ) > ϕ (t ) (j = m+1 to n):
c j ful j
ϕ (t ) shall be calculated by Formula (3).
ful j
8 © ISO 2013 – All rights reserved

6.4.4 Calculation of cooling seasonal energy consumption (CSEC)
Cooling seasonal energy consumption (CSEC), C , shall be determined using Formula (6) from the total
CSE
sum of cooling energy consumption at each outdoor temperature t .
j
n
n
j
CX=×()tP ()t × (6)
CSE ∑ jful j
Ft()
PL j
j=1
Operation factor X(t ) shall be calculated by Formula (7).
j
Lt()
cj
Xt()= (7)
j
φ()t
j
In the case of L (t ) > ϕ(t ), X(t ) = 1.
c j j j
Part load factor (PLF), F (t ), caused by the equipment when it is cyclically operated at outdoor
PL j
temperature t , shall be determined by Formula (8) using degradation coefficient C .
j D
F (t ) = 1 − C (1 − X(t ))
PL j D j
(8)
a) Cyclic operation (L (t ) ≤ ϕ (t )):
c j ful j
In Formula (6), X(t ) shall be calculated by Formula (7).
j
In Formula (7), ϕ(t ) = ϕ (t ).
j ful j
b) Full capacity operation (L (t ) > ϕ (t )):
c j ful j
In Formula (6), X(t ) = F (t ) = 1.
j PL j
6.5 Cooling seasonal characteristics of two-stage capacity units
Coefficients specified in
...