ISO 13256-1:2021

INTERNATIONAL ISO
STANDARD 13256-1
Second edition
2021-05
Water-source heat pumps — Testing
and rating for performance —
Part 1:
Water-to-air and brine-to-air heat
pumps
Pompes à chaleur à eau — Essais et détermination des
caractéristiques de performance —
Partie 1: Pompes à chaleur eau-air et eau glycolée-air
Reference number
©
ISO 2021
© ISO 2021
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ii © ISO 2021 – All rights reserved

Contents Page
Foreword .v
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Rating and test conditions . 6
5.1 Rating conditions for the determination of net capacities . 6
5.1.1 Ratings . 6
5.1.2 Power input of fans for heat pumps without duct connection . 6
5.1.3 Power input of fans for heat pumps with duct connection . 6
5.1.4 Power input of liquid pumps . 7
5.1.5 Airflow rates . 7
5.1.6 Liquid flow rates . 8
5.1.7 Test liquids . 9
5.2 Rating test conditions for cooling and heating capacities . 9
6 Performance Requirements.10
6.1 General .10
6.2 Maximum operating conditions test .10
6.2.1 Test conditions.10
6.2.2 Test procedures.10
6.2.3 Test requirements .11
6.3 Minimum operating conditions test .12
6.3.1 Test conditions.12
6.3.2 Test procedures.12
6.3.3 Test requirements .12
6.4 Enclosure sweat and condensate test .13
6.4.1 General.13
6.4.2 Test conditions.13
6.4.3 Test procedures.14
6.4.4 Test requirements .14
7 Test methods .14
7.1 General .14
7.2 General test requirements .14
7.3 Equipment installation .14
7.4 Cooling and heating capacity tests procedure .15
7.4.1 General.15
7.4.2 Reconditioning period .15
7.4.3 Data collection period .15
7.4.4 Net total cooling capacity .15
7.4.5 Net heating capacity .16
7.5 Uncertainties of measurement .16
7.6 Data to be recorded .16
7.7 Uncertainties of measurements and permissible deviations for steady-state
cooling and heating capacity tests .17
7.8 Test results.19
8 Marking provisions .19
8.1 Nameplate requirements .19
8.2 Nameplate information .19
8.3 Designation of standard ratings capacity.19
8.4 Refrigerant designation .20
9 Publication of ratings .20
9.1 Published ratings .20
9.2 Additional ratings .20
Annex A (normative) Test requirements .21
Annex B (informative) Airflow measurement .28
Annex C (normative) Indoor air enthalpy test method .35
Annex D (informative) Refrigerant enthalpy test method .38
Annex E (normative) Liquid enthalpy test method .40
Annex F (informative) Correction of fan or pump power input for external static pressures
other than zero .42
Annex G (informative) Additional ratings based upon previous standard version
ISO 13256-1:1998.43
Annex H (informative) Cooling condensate measurements .44
Bibliography .45
iv © ISO 2021 – All rights reserved

Foreword
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