EN 12900:2025

SLOVENSKI STANDARD
01-maj-2025
Nadomešča:
SIST EN 12900:2013
Kompresorji za hladilne tekočine - Pogoji določanja nazivne moči, toleranc in
predstavitev tehničnih karakteristik
Refrigerant compressors - Rating conditions, tolerances and presentation of
performance data
Kältemittel-Verdichter - Nennbedingungen, Toleranzen und Darstellung von
Leistungsdaten
Compresseurs pour fluides frigorigènes - Détermination des caractéristiques, tolérances
et présentation des données de performance
Ta slovenski standard je istoveten z: EN 12900:2025
ICS:
23.140 Kompresorji in pnevmatični Compressors and pneumatic
stroji machines
27.200 Hladilna tehnologija Refrigerating technology
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12900
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2025
EUROPÄISCHE NORM
ICS 23.140; 27.200 Supersedes EN 12900:2013
English Version
Refrigerant compressors - Rating conditions, tolerances
and presentation of performance data
Compresseurs pour fluides frigorigènes - Kältemittel-Verdichter - Nennbedingungen, Toleranzen
Détermination des caractéristiques, tolérances et und Darstellung von Leistungsdaten
présentation des données de performance
This European Standard was approved by CEN on 10 February 2025.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12900:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Rating Conditions . 8
4.1 General. 8
Ambient temperature around the compressor . 8
Subcooling . 8
Gas cooler outlet temperature . 8
Application of economising . 8
5 Performance data . 9
5.1 General. 9
5.2 Tabular or graphical form . 10
5.3 Polynomial form . 10
6 Standard reference points . 11
7 Tolerances . 13
8 Conversion methods . 16
8.1 Suction gas superheat . 16
8.2 Compressor speed for open drive compressors . 16
Annex A (informative) Calculation of dew point temperatures from given mean temperatures 17

European foreword
This document (EN 12900:2025) has been prepared by Technical Committee CEN/TC 113 “Heat pumps and
air conditioning units”, the secretariat of which is held by UNE.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by September 2025, and conflicting national standards shall be
withdrawn at the latest by September 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 12900:2013.
a) Clause 2 “Normative References” was updated;
b) Clause 3 “Terms and definitions” was modified e.g. definition of heating capacity was added;
c) Clause 4 has been renamed, restructured and revised to simplify it;
d) the content of the old clause “Requirements” was integrated into the clause “Performance data”;
e) Annex A “Calculation of dew point temperatures from given mean temperatures” was added;
f) the document was revised editorially.
Any feedback and questions on this document should be directed to the users’ national standards body. A
complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia,
Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United Kingdom.
Introduction
The performance data of a refrigerant compressor is commonly expressed as the refrigerating capacity and
power consumption when applied in an ideal refrigeration cycle. An ideal cycle is one in which there is no
pressure drop or heat transmission through the pipework between the major circuit components. Optionally,
the heating capacity, i.e. heat delivered by the condenser or gas cooler, can be shown.
This document defines the conditions for presentation of performance data, so that different compressors can
be compared.
1 Scope
This document specifies the rating conditions, tolerances and the method of presenting performance data of
refrigerant compressors to enable comparison of different compressors.
This document is applicable to single-stage compressor and two-stage compressor data with or without an
additional intermediate pressure inlet.
The performance data of compressors used with R-744 in transcritical operation are covered in this document.
The data relating to the refrigerating capacity, heating capacity and power absorbed include requirements for
part-load operation where applicable.
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.
EN 13771-1, Compressors and condensing units for refrigeration — Performance testing and test methods —
Part 1: Refrigerant compressors
EN 378-1:2016+A1:2020, Refrigerating systems and heat pumps — Safety and environmental requirements —
Part 1: Basic requirements, definitions, classification and selection criteria
ISO 817, Refrigerants — Designation and safety classification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 378-1:2016+A1:2020:2021 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
compressor
device for mechanically increasing the pressure of a refrigerant vapour
[SOURCE: EN 378-1:2016+A1:2020, 3.4.3]
3.2
refrigerating capacity
product of the refrigerant low-pressure mass flow rate through the compressor and the specific refrigerant
enthalpy difference between the compressor low pressure inlet and the state defined by subcooling, gas cooler
outlet conditions or liquid temperature at inlet of the low-pressure evaporator
Note 1 to entry: For single-stage cycles the enthalpy difference is h1-h3 in the respective p-h diagram. For multi-stage
expansion cycles it is h1-h4 in the respective p-h diagram.
Note 2 to entry: The refrigerant at the low stage compressor inlet is superheated above the suction dew point
temperature to the stated value.

a) p-h diagram for single-stage cycles b) p-h diagram for multi-stage cycles
Key
1: compressor inlet III: expansion
2: compressor outlet IV: evaporation
3: inlet of the expansion device h: specific enthalpy
4: inlet of the low stage expansion device m: compressor suction mass flow rate
I: compression p: pressure
II: condensation
Figure 1 — p-h diagram
3.3
heating capacity
Q
h
sum of refrigerating capacity and power absorbed
Note 1 to entry: As simplification, all losses (compressor and inverter heat losses) for the power absorbed are assumed
to create useful heat
3.4
subcooling
difference between the bubble point temperature of the refrigerant for a given pressure and the temperature
of the liquid refrigerant
Note 1 to entry: The given pressure can be the compressor discharge pressure or the flash tank pressure.
3.5
suction gas superheat
difference between the dew point temperature of the refrigerant corresponding to the compressor suction
pressure and the suction gas temperature of the refrigerant at the compressor inlet
3.6
power absorbed
〈open type compressors〉 power at the compressor shaft
3.7
power absorbed
electrical power input at the motor
terminals
3.8
power absorbed
electrical power input at the
inverter input terminals
3.9
refrigerating coefficient of performance
COP
r
ratio of refrigerating capacity to the power absorbed
3.10
subcritical operation
operating condition with discharge pressure level below the critical pressure
3.11
transcritical operation
operating condition with discharge pressure level above the critical pressure
3.12
part load operation
for compressors with capacity control mechanism, part load is interpreted as operation with active capacity
control at reduced capacity
3.13
fluid
refrigerant liquid, gas or vapour including the state of appearance close to and above the critical pressure
3.14
evaporating temperature
t0
temperature between the evaporating dew point and the evaporator inlet temperature of the refrigerant at
the pressure of the compressor inlet
Note 1 to entry: For refrigerants without glide the evaporating temperature is equal to the dew point temperature at the
compressor inlet pressure.
Note 2 to entry: For refrigerants with glide, the evaporating temperature is defined as dew point temperature, as
arithmetic mean temperature or thermodynamic mean temperature as calculated according to Annex A.
3.15
condensing temperature
t
c
temperature between the condensing dew point and the bubble point of the refrigerant at the compressor
discharge pressure
Note 1 to entry: For refrigerants without glide the condensing temperature is equal to the dew point temperature at the
compressor discharge pressure.
Note 2 to entry: For refrigerants with glide the condensing temperature is defined as dew point, as arithmetic mean or
thermodynamic mean temperature as calculated according to Annex A
...