EN 16905-4:2026
(Main)Gas-fired endothermic engine driven heat pumps - Part 4: Test methods
- Abstract
This document specifies the requirements, test methods and test conditions for the rating and performance calculation of gas-fired endothermic engine driven heat pumps for heating and/or cooling mode including the engine heat recovery, to be used outdoor.
This document specifies the test conditions, tests methods and seasonal performances calculation methods.
This document only applies to appliances with a maximum heat input (based on net calorific value) not exceeding 70 kW at standard rating conditions.
This document only applies to appliances under categories I2H, I2E, I2Er, I2R, I2E(S)B, I2L, I2LL, I2ELL, I2E(R)B, I2ESi, I2E(R), I3P, I3B, I3B/P, II2H3+, II2Er3+, II2H3B/P, II2L3B/P, II2E3B/P, II2ELL3B/P, II2L3P, II2H3P, II2E3P and II2Er3P according to EN 437:2021.
This document only applies to appliances having:
a) gas fired endothermic engines under the control of fully automatic control systems;
b) closed system refrigerant circuits in which the refrigerant does not come into direct contact with the fluid to be cooled or heated;
c) where the temperature of the heat transfer fluid of the heating system (heating water circuit) does not exceed 105 °C during normal operation;
d) where the maximum operating pressure in the:
1) heating water circuit (if installed) does not exceed 6 bar;
2) domestic hot water circuit (if installed) does not exceed 10 bar.
This document applies to GEHP appliances only when used for space heating or space cooling or for refrigeration, with or without heat recovery.
This document is applicable to GEHP appliances that are intended to be type tested. Requirements for GEHP appliances that are not type tested would need to be subject to further consideration.
- Status
- Published
- Publication Date
- 08-Sep-2026
- Technical Committee
- CEN/TC 299 - Gas-fired sorption appliances and domestic gas-fired washing and drying appliances
- Drafting Committee
- CEN/TC 299/WG 3 - Gas-fired endothermic engine heat pumps
- Current Stage
- 6060 - Definitive text made available (DAV) - Publishing
- Start Date
- 09-Sep-2026
- Due Date
- 06-Sep-2023
- Completion Date
- 09-Sep-2026
EN 16905-4:2026 is a CEN European Standard for gas-fired endothermic engine driven heat pumps (GEHP) used outdoors. It sets the test methods, test conditions and calculation methods used to rate heating and cooling performance, including engine heat recovery, for appliances intended for type testing.
What does EN 16905-4:2026 specify?
EN 16905-4:2026 specifies how to test and rate GEHP appliances in heating mode, cooling mode and refrigeration use, with or without heat recovery. It focuses on the test conditions and methods needed to calculate capacities, efficiencies and seasonal-performance inputs in a repeatable way.
The scope is limited to appliances with a maximum heat input of 70 kW at standard rating conditions, certain appliance categories according to EN 437:2021, fully automatic control, closed refrigerant circuits, heating water up to 105 °C in normal operation, and the stated pressure limits for heating water and domestic hot water circuits. The document is for appliances used outdoors and intended to be type tested.
The introduction states that single split and multisplit systems are covered, while appliances whose condenser is cooled by air and by evaporation of external additional water are not covered.
| Annex | What it covers |
|---|---|
| Annex A | Calorimeter test method, including calorimeter room arrangements and capacity calculations |
| Annex C | Symbols and units used in the calorimeter and indoor enthalpy methods |
| Annex D | Water enthalpy test method and its calculation approach |
| Annex E | Compensation systems for air-to-water and water-to-water tests |
| Annex F | Measurement control criteria for water-to-water and water-to-brine appliances |
| Annex G | Determination of liquid pump efficiency |
| Annex H | Part-load calculation procedures for GUE, AEF and Cd |
| Annex I | An individual correction used in global electrical power input correction |
| Annex J | Heating capacity test flow chart and example test sequences |
| Annex K | Rating of indoor and outdoor units of multisplit and modular heat recovery multisplit systems |
| Annex M | Air flow measurement |
| Annex ZA to ZC | Relationships with EU ecodesign and energy-labelling requirements |
What are the key requirements of EN 16905-4:2026?
EN 16905-4:2026 is mainly a laboratory test standard. Its key requirements are the test setup, the calculation framework, the measurement tolerances, the heating and cooling test procedures, and the way results are reported.
Calculation framework for capacities and efficiencies
Clause 4.2 sets the basic calculation principles for measured capacity, effective capacity and rating capacity. It also defines how to derive engine heat recovery capacity and the performance indicators used for reporting and seasonal calculations, including Gas Utilization Efficiency (GUE), Engine Heat Recovery Efficiency (EHRE), Auxiliary Energy Factor (AEF), Auxiliary Energy Engine Heat Recovery Factor (AEHRF), Total Gas Utilization Efficiency and Primary Energy Factor (PER).
In practice, this means the test report is not just a list of temperatures and flows. The measured values are turned into performance figures that compare useful heating or cooling output with gas input and electrical auxiliaries.
Test apparatus, installation and measurement uncertainty
Clause 4.3 requires the apparatus arrangement and appliance installation to match the test method being used, including the way multi-part units and ducted units are connected. Clause 4.4 then limits the uncertainty of the individual measurements, such as temperatures, flow rates, pressures, gas input, power and time.
This matters because a result is only meaningful if the test rig is controlled tightly enough. The document also sets overall uncertainty limits for steady-state capacities, transient defrost testing, air-enthalpy testing and water-enthalpy testing, so laboratories can judge whether a result is valid.
Heating and cooling test procedure
Clause 4.5 provides the general procedure for non-cyclical and cyclical operation. For heating tests, the document uses a preconditioning period, a one-hour equilibrium period and a data collection period, with specific rules for when a test is classed as steady-state or transient.
The key practical point is the treatment of defrost. If performance drifts too much during the first 70 minutes, or if defrost occurs at the wrong point, the test is restarted or reclassified as transient. Annex J gives a flow chart and example sequences, which helps laboratories follow the sequence without guessing.
Part-load and cycling performance
Clause 4.5.2.3.10 and Clause 4.5.3 cover reduced-load and cyclical operation. The standard uses separate approaches for fixed-capacity and variable-capacity units, and Annex H explains how to calculate part-load GUE, part-load AEF and the degradation coefficient Cd.
For a reader, this is the part that matters when the product does not run at full load all the time. It shows how cycling losses and restart behaviour are taken into account, which affects declared seasonal performance and product comparison.
Electrical power consumption in non-heating operation
Clause 4.6 covers electrical power consumption during thermostat off mode, standby mode, crankcase heater mode and off mode. These measurements feed into the overall energy picture, not just the active heating or cooling test.
This is important because auxiliary consumption can change the seasonal result noticeably. A product with low active power may still perform differently in the field if standby and off-mode consumption is high.
Multisplit heat recovery systems
Clause 5 gives the heat recovery test for air-cooled multisplit systems. It specifies the test installation, including the three-room calorimeter method, the three-room air-enthalpy method and the two-room air-enthalpy method, and it requires all operating indoor units to be included.
The result is accepted only if the overall energy balance is close enough. For laboratories and manufacturers, this is the core method for systems where several indoor units operate together and heating and cooling can occur at the same time.
Test report content
Clause 6 lists the minimum information to record in the test report, including the test date, laboratory, location, method, supervisor, appliance designation, refrigerant, heat transfer medium and reference to the standard. It also requires the key rating results, such as effective capacities, gas and electrical inputs, GUE, AEF and static pressure.
That makes the report traceable for audits, certification work and technical file preparation.
What terms does EN 16905-4:2026 define?
EN 16905-4:2026 uses the terms and definitions from EN 16905-1:2017, and several abbreviations are central to the test calculations.
- Gas-fired endothermic engine driven heat pump (GEHP) - a heat pump driven by a gas-fired endothermic engine, used here for space heating, space cooling or refrigeration.
- Gas Utilization Efficiency (GUE) - an efficiency indicator based on useful output relative to gas input.
- Engine Heat Recovery Efficiency (EHRE) - the share of engine heat recovery relative to the relevant operating condition.
- Auxiliary Energy Factor (AEF) - an indicator that captures the effect of auxiliary electrical energy such as fans and pumps.
- Auxiliary Energy Engine Heat Recovery Factor (AEHRF) - the corresponding factor for the engine heat recovery part of the system.
- Primary Energy Factor (PER) - the overall factor used for primary-energy-based performance assessment.
- Degradation coefficient (Cd) - the part-load cycling coefficient used to account for performance loss during repeated start-stop operation.
- External static pressure (ESP) - the pressure setting used for ducted and airflow-related testing.
Who uses EN 16905-4:2026?
EN 16905-4:2026 is used by manufacturers, test laboratories, certification bodies, and technical teams that prepare product files or verify declared performance. It is also relevant to quality managers and buyers who need to check whether a test report is based on a recognized method.
In practice, it supports type testing of GEHP appliances, including single split and multisplit systems, and it is used when rating heating capacity, cooling capacity, heat recovery and seasonal-performance inputs. It is especially relevant for outdoor appliances, ducted and non-ducted units, and systems with air, water or brine heat-transfer media.
What changed in EN 16905-4:2026 from the previous edition?
EN 16905-4:2026 supersedes EN 16905-4:2017. The foreword states that the revision includes editorial and technical changes throughout the draft and in Annex ZA and Annex ZB to align the text with Commission Regulation (EU) No 813/2013, and it adds Annex ZC to align with Commission Regulation (EU) No 2016/2281.
Which standards are used with EN 16905-4:2026?
EN 16905-4:2026 is used together with several companion standards named in the scope and normative references.
- EN 16905-1:2017 - gives the terms and definitions used across the EN 16905 series.
- prEN 16905-2:2021 - covers safety.
- EN 16905-3:2017 - covers the test conditions used with these test methods.
- prEN 16905-5:2021 - covers calculation of seasonal performances in heating and cooling mode.
- EN 437:2021 - provides appliance categories, test gases and test pressures.
- EN 14511-3:2018 - provides test methods for related heat-pump and chiller measurement work.
- EN 14511-2:2018 and EN 14825:2022 - are named in the scope as companion standards for test conditions and seasonal-performance work.
- FprEN 12102-1:2022 - provides the sound power level test method referenced for rating conditions.
- EN ISO 5167-1 and EN ISO 5801 - may be used for air flow measurement in Annex M.
- EN 15502-2-2:2014 - is used in Annex F for the flue gas-loss calculation referenced in the measurement control criteria.
What does the EN 16905-4:2026 document contain?
EN 16905-4:2026 contains calculation methods, apparatus arrangements, measurement tolerances, test procedures and reporting rules. It includes formula sets for capacities and efficiency indices, and it also includes tables for uncertainties and the data that need to be recorded.
Several annexes give practical test tools: calorimeter arrangements, water enthalpy calculations, compensation systems, pump-efficiency calculations, part-load and cycling procedures, multisplit rating methods, airflow measurement arrangements and worked test-sequence examples. The closing annexes link the document to EU ecodesign and energy-labelling requirements, so the same test results can support regulatory declaration work.
Relations
- Effective Date
- 19-Jan-2023
- Referred By
EN 16905-3:2024 - Gas-fired endothermic engine-driven heat pumps - Part 3: Test conditions - Effective Date
- 16-Sep-2026
- Effective Date
- 16-Sep-2026
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Frequently Asked Questions
EN 16905-4:2026 is a draft published by the European Committee for Standardization (CEN). Its full title is "Gas-fired endothermic engine driven heat pumps - Part 4: Test methods". This standard covers: This document specifies the requirements, test methods and test conditions for the rating and performance calculation of gas-fired endothermic engine driven heat pumps for heating and/or cooling mode including the engine heat recovery, to be used outdoor. This document specifies the test conditions, tests methods and seasonal performances calculation methods. This document only applies to appliances with a maximum heat input (based on net calorific value) not exceeding 70 kW at standard rating conditions. This document only applies to appliances under categories I2H, I2E, I2Er, I2R, I2E(S)B, I2L, I2LL, I2ELL, I2E(R)B, I2ESi, I2E(R), I3P, I3B, I3B/P, II2H3+, II2Er3+, II2H3B/P, II2L3B/P, II2E3B/P, II2ELL3B/P, II2L3P, II2H3P, II2E3P and II2Er3P according to EN 437:2021. This document only applies to appliances having: a) gas fired endothermic engines under the control of fully automatic control systems; b) closed system refrigerant circuits in which the refrigerant does not come into direct contact with the fluid to be cooled or heated; c) where the temperature of the heat transfer fluid of the heating system (heating water circuit) does not exceed 105 °C during normal operation; d) where the maximum operating pressure in the: 1) heating water circuit (if installed) does not exceed 6 bar; 2) domestic hot water circuit (if installed) does not exceed 10 bar. This document applies to GEHP appliances only when used for space heating or space cooling or for refrigeration, with or without heat recovery. This document is applicable to GEHP appliances that are intended to be type tested. Requirements for GEHP appliances that are not type tested would need to be subject to further consideration.
This document specifies the requirements, test methods and test conditions for the rating and performance calculation of gas-fired endothermic engine driven heat pumps for heating and/or cooling mode including the engine heat recovery, to be used outdoor. This document specifies the test conditions, tests methods and seasonal performances calculation methods. This document only applies to appliances with a maximum heat input (based on net calorific value) not exceeding 70 kW at standard rating conditions. This document only applies to appliances under categories I2H, I2E, I2Er, I2R, I2E(S)B, I2L, I2LL, I2ELL, I2E(R)B, I2ESi, I2E(R), I3P, I3B, I3B/P, II2H3+, II2Er3+, II2H3B/P, II2L3B/P, II2E3B/P, II2ELL3B/P, II2L3P, II2H3P, II2E3P and II2Er3P according to EN 437:2021. This document only applies to appliances having: a) gas fired endothermic engines under the control of fully automatic control systems; b) closed system refrigerant circuits in which the refrigerant does not come into direct contact with the fluid to be cooled or heated; c) where the temperature of the heat transfer fluid of the heating system (heating water circuit) does not exceed 105 °C during normal operation; d) where the maximum operating pressure in the: 1) heating water circuit (if installed) does not exceed 6 bar; 2) domestic hot water circuit (if installed) does not exceed 10 bar. This document applies to GEHP appliances only when used for space heating or space cooling or for refrigeration, with or without heat recovery. This document is applicable to GEHP appliances that are intended to be type tested. Requirements for GEHP appliances that are not type tested would need to be subject to further consideration.
EN 16905-4:2026 is classified under the following ICS (International Classification for Standards) categories: 27.080 - Heat pumps. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 16905-4:2026 has the following relationships with other standards: It is inter standard links to EN 16905-4:2017, EN 16905-3:2024, EN 16905-5:2022. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN 16905-4:2026 is associated with the following European legislation: EU Directives/Regulations: 2016/2281, 811/2013, 813/2013; Standardization Mandates: M/535, M/560. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
EN 16905-4:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 16905-4:2022
01-julij-2022
Toplotna črpalka s plinsko gnanim motorjem z notranjim zgorevanjem - 4. del:
Preskusne metode
Gas-fired endothermic engine driven heat pumps - Part 4: Test methods
Gasbefeuerte endothermische Motor-Wärmepumpen - Teil 4: Prüfverfahren
Pompes à chaleur à moteur endothermique alimenté au gaz - Partie 4 : Méthodes
d'essai
Ta slovenski standard je istoveten z: prEN 16905-4
ICS:
27.080 Toplotne črpalke Heat pumps
oSIST prEN 16905-4:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN 16905-4:2022
oSIST prEN 16905-4:2022
DRAFT
EUROPEAN STANDARD
prEN 16905-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2022
ICS 27.080 Will supersede EN 16905-4:2017
English Version
Gas-fired endothermic engine driven heat pumps - Part 4:
Test methods
Pompes à chaleur à moteur endothermique alimenté Gasbefeuerte endothermische Motor-Wärmepumpen -
au gaz - Partie 4 : Méthodes d'essai Teil 4: Prüfverfahren
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 299.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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, Turkey and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 16905-4:2022 E
worldwide for CEN national Members.
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
Contents Page
European foreword . 6
Introduction . 7
1 Scope . 8
2 Normative references . 9
3 Terms and definitions . 9
4 Test methods . 9
4.1 General . 9
4.2 Basic principles method of calculation for the determination of capacities . 10
4.2.1 Capacity. 10
4.2.2 Engine heat recovery capacity . 12
4.2.3 Heat input . 14
4.2.4 Electrical power input . 15
4.2.5 Gas utilization efficiency (GUE) . 19
4.2.6 Engine heat recovery efficiency (EHRE) . 20
4.2.7 Total gas utilization efficiency (GUE ) . 21
T
4.2.8 Auxiliary energy factor (AEF) . 22
4.2.9 Auxiliary energy engine heat recovery factor (AEHRF) . 23
4.2.10 Total auxiliary energy factor (AEF ) . 24
T
4.2.11 Primary energy factor (PER) . 24
4.3 Test apparatus. 25
4.3.1 Arrangement of the test apparatus. 25
4.3.2 Installation and connection of the appliance . 26
4.4 Uncertainties of measurement . 28
4.5 Test procedure . 29
4.5.1 General . 29
4.5.2 Non-cyclical operation . 33
4.5.3 Cyclical operation . 46
4.6 Test methods for electric power consumption during thermostat off mode, standby
mode and off mode . 50
4.6.1 Measurement of electrical power consumption during thermostat off mode . 50
4.6.2 Measurement of the electrical power consumption during standby mode . 50
4.6.3 Measurement of the electric power consumption during crankcase heater mode . 50
4.6.4 Measurement of the electric power consumption during off mode . 51
4.7 Test results — Data to be recorded . 51
5 Heat recovery test for air-cooled multisplit systems . 53
5.1 Test installation . 53
5.1.1 General . 53
5.1.2 Three-room calorimeter method . 53
5.1.3 Three-room air-enthalpy method . 53
5.1.4 Two-room air-enthalpy method . 54
5.2 Test procedure . 54
5.3 Test results . 54
6 Test report . 54
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
6.1 General information . 54
6.2 Additional information . 55
6.3 Rating test results . 55
Annex A (normative) Calorimeter test method . 56
A.1 General . 56
A.2 Calibrated room-type calorimeter . 58
A.3 Balanced ambient room-type calorimeter . 59
A.4 Calculations-cooling capacities . 59
A.4.1 General . 59
A.4.2 Total cooling capacity on the indoor-side . 61
A.4.3 Total cooling capacity of liquid (water)-cooled equipment deducted from the
condenser side . 61
A.4.4 Latent cooling capacity (room dehumidifying capacity) . 61
A.4.5 Sensible cooling capacity . 62
A.4.6 Sensible cooling capacity . 62
A.5 Calculation-heating capacities . 62
A.5.1 General . 62
A.5.2 Determination of the heating capacity by measurements in the indoor-side room . 63
A.5.3 Determination of the heating capacity by measurements in the outdoor-side room . 64
A.5.4 Total heating capacity of liquid (water)-to-air unit deducted from the water side . 64
Annex B (normative) Indoor air enthalpy test method . 65
B.1 General . 65
B.2 Test conditions . 65
B.3 Application . 65
B.4 Calculations-cooling capacities . 66
B.5 Calculations-heating capacities . 66
Annex C (normative) Symbols and units used in Annex A and B . 67
Annex D (normative) Water enthalpy test method . 69
D.1 General . 69
D.2 Calculations. 69
D.2.1 Measured cooling capacity . 69
D.2.2 Measured heating capacity. 69
D.2.3 Measured engine heat recovery capacity. 70
Annex E (informative) Direct method for air-to-water (brine) and water (brine)-to-water
(brine) appliances . 71
E.1 Introduction. 71
E.2 Compensation system for air-to-water (brine) appliances . 71
E.3 Compensation system for water (brine) to water (brine) appliances . 72
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
E.4 General . 73
Annex F (informative) Measurement control criteria for water (brine) to water (brine)
appliances . 74
F.1 Water (brine)-to-water (brine) heat pump in heating mode . 74
F.2 Water (brine)-to-water (brine) chiller or chiller/heater in cooling mode . 75
Annex G (normative) Determination of the liquid pump efficiency . 77
G.1 General . 77
G.2 Hydraulic power of the liquid pump . 77
G.2.1 The liquid pump is an integral part of the appliance . 77
G.2.2 The liquid pump is not an integral part of the appliance . 77
G.3 Efficiency of integrated pumps . 77
G.3.1 Glandless circulators . 77
G.3.2 Dry motor pumps . 78
G.4 Efficiency of non-integrated pumps . 80
Annex H (informative) Calculation procedure for determination of GUE, AEF and Cd values . 81
H.1 Calculation procedure for determination of GUE values at part load (GUEPL) . 81
H.1.1 General . 81
H.1.2 For air-to-air, brine-to-air and water-to-air units . 81
H.1.3 For air-to-water, water-to-water and brine-to-water units . 82
H.2 Calculation procedure for determination of AEF values at part load (AEFPL) . 83
H.2.1 General . 83
H.2.2 For air-to-air, brine-to-air and water-to-air units . 83
H.2.3 For air-to-water, water-to-water and brine-to-water units . 83
H.3 Air-to-air and water-to-air units - Determination of the degradation coefficient Cd. 84
H.3.1 General . 84
H.3.2 Air-to-air units – Cooling mode . 85
H.3.3 Air-to-air units – Heating mode . 85
H.3.4 Water-to-air units – Cooling mode . 85
H.3.5 Water-to-air units – Heating mode . 85
H.4 Air-to-water(brine) units and water(brine)-to-water(brine) and DX-to-water(brine)
units - Determination of the degradation coefficient Cd . 85
Annex I (informative) “Individual” correction to include in the “global” electrical power
input correction depending on the GEHP appliance . 87
Annex J (informative) Heating capacity tests - Flow chart and examples of different test
sequences . 94
J.1 Flow chart . 94
J.2 Examples of test profiles . 95
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
Annex K (normative) Rating of indoor and outdoor units of multisplit and modular heat
recovery multisplit system . 100
K.1 General . 100
K.2 Terms and definitions . 100
K.3 Rating of indoor units . 101
K.3.1 General . 101
K.3.2 Air flow rate measurement . 101
K.3.3 Measurement of the power input of indoor units . 101
K.4 Rating of outdoor units . 101
K.4.1 General . 101
K.4.2 Test conditions . 102
K.4.3 Test procedure . 102
K.4.4 Calculation of the SPER based on the PER outdoor . 102
c c-
K.4.5 Calculation of the SPER based on the PER outdoor . 102
h h-
Annex L (normative) Testing and rating of individual indoor units . 103
L.1 Indoor unit under test . 103
L.2 Test methods . 103
L.2.1 General . 103
L.2.2 Calorimeter method. 103
L.2.3 Air-enthalpy method . 104
L.3 Test conditions . 104
L.4 Rated performance . 105
L.5 Data to be recorded. 105
Annex M (informative) Air flow measurement . 108
M.1 General . 108
M.2 Test installation . 108
M.3 Test conditions . 108
M.4 Air flow measurement . 108
Annex ZA (informative) Relationship between this European Standard and the ecodesign
requirements of Commission Regulation (EU) No 813/2013 aimed to be covered . 109
Annex ZB (informative) Relationship between this European Standard and the energy
labelling requirements of Commission Delegated Regulation (EU) No 811/2013
aimed to be covered . 110
Annex ZC (informative) Relationship between this European Standard and the ecodesign
requirements of Commission Regulation (EU) No 2016/2281 aimed to be covered. 111
Bibliography . 112
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
European foreword
This document (prEN 16905-4:2022) has been prepared by Technical Committee CEN/TC 299 “Gas-fired
sorption appliances, indirect fired sorption appliances, gas-fired endothermic engine heat pumps and
domestic gas-fired washing and drying appliances”, the secretariat of which is held by UNI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 16905-4:2017.
In comparison with the previous edition, the following technical modifications have been made:
— Editorial and technical changes throughout the draft and in Annex ZA, ZB in order to align the text to
the Ecodesign Requirements of Commission Regulation (EU) No 813/2013;
— Addition of Annex ZC in order to align the text to the Ecodesign Requirements of Commission
Regulation (EU) No 2016/2281.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of EU
Directive(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, ZB or ZC, which is an
integral part of this document.
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
Introduction
The GEHP appliances having their condenser cooled by air and by the evaporation of external additional
water are not covered by this document.
Single split and multisplit systems are covered by this document.
The GEHP appliances can have one or more primary or secondary functions.
This document specifies the requirements, test methods and test conditions concerning, in particular, the
construction, safety, fitness for purpose, and rational use of energy, for the rating and performance
calculation of air conditioners and heat pumps using either air, water or brine as heat transfer media,
with gas-fired endothermic engine driven compressors when used for space heating, cooling and
refrigeration, hereafter referred to as “GEHP appliance”.
EN 16905 comprises the following parts under the general title, Gas-fired endothermic engine driven
heat pumps:
— Part 1: Terms and definitions;
— Part 2: Safety;
— Part 3: Tests conditions;
— Part 4: Tests methods;
— Part 5: Calculation of seasonal performances in heating and cooling mode.
prEN 16905-4:2022 has been prepared to address the essential requirements of the European Regulation
(EU) 2016/426 relating to appliances burning gaseous fuels and repealing Directive 2009/142/EC (see
prEN 16905-4:2022, Annex ZA).
EN 16905-1:2017, prEN 16905-2:2021, EN 16905-3:2017, prEN 16905-4:2022 and prEN 16905-5:2021
are linked to the Energy Related Products Directive (2009/125/EC) in terms of tests conditions, tests
methods and seasonal performances calculation methods under Mandate M/535; (see EN 16905- 3:2017,
Annex ZA, prEN 16905-4:2022, Annex ZA, prEN 16905-5:2021, Annex ZA and prEN 16905-2:2021,
Annexes ZB and ZC).
These documents will be reviewed whenever new mandates could apply.
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
1 Scope
This document specifies the requirements, test methods and test conditions for the rating and
performance calculation of gas-fired endothermic engine driven heat pumps for heating and/or cooling
mode including the engine heat recovery, to be used outdoor.
This document specifies the test conditions tests methods and seasonal performances calculation
methods.
This document is to be used in conjunction with:
a) the terms and conditions, EN 16905-1:2017
b) the safety, prEN 16905-2:2021
c) the test conditions, EN 16905-3:2017
d) the calculation of seasonal performances in heating and cooling mode, prEN 16905-5:2021
e) the heat pump standards, EN 14511-2:2018, EN 14511-3:2018 and EN 14825:2022.
This document only applies to appliances with a maximum heat input (based on net calorific value) not
exceeding 70 kW at standard rating conditions.
This document only applies to appliances under categories I , I , I , I , I , I , I , I , I , I ,
2H 2E 2Er 2R 2E(S)B 2L 2LL 2ELL 2E(R)B 2ESi
I , I , I , I II +, II +, II , II , II , II , II , II , II and II according to
2E(R) 3P 3B 3B/P, 2H3 2Er3 2H3B/P 2L3B/P 2E3B/P 2ELL3B/P 2L3P 2H3P 2E3P 2Er3P
EN 437:2021.
This document only applies to appliances having:
a) gas fired endothermic engines under the control of fully automatic control systems;
b) closed system refrigerant circuits in which the refrigerant does not come into direct contact with the
fluid to be cooled or heated;
c) where the temperature of the heat transfer fluid of the heating system (heating water circuit) does
not exceed 105 °C during normal operation;
d) where the maximum operating pressure in the:
1) heating water circuit (if installed) does not exceed 6 bar;
2) domestic hot water circuit (if installed) does not exceed 10 bar.
This document applies to GEHP appliances only when used for space heating or space cooling or for
refrigeration, with or without heat recovery.
This document is applicable to GEHP appliances that are intended to be type tested. Requirements for
GEHP appliances that are not type tested would need to be subject to further consideration.
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
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 437:2021, Test gases - Test pressures - Appliance categories
EN 14511-3:2018, Air conditioners, liquid chilling packages and heat pumps for space heating and cooling
and process chillers, with electrically driven compressors - Part 3: Test methods
EN 16905-1:2017, Gas-fired endothermic engine driven heat pumps - Part 1: Terms and definitions
prEN 16905-2:2021, Gas-fired endothermic engine driven heat pumps — Part 2: Safety
EN 16905-3:2017, Gas-fired endothermic engine driven heat pumps - Part 3: Test conditions
prEN 16905-5:2021, Gas-fired endothermic engine driven heat pumps — Part 5: Calculation of seasonal
performances in heating and cooling mode
FprEN 12102-1:2022, Air conditioners, liquid chilling packages, heat pumps, process chillers and
dehumidifiers with electrically driven compressors - Determination of the sound power level - Part 1: Air
conditioners, liquid chilling packages, heat pumps for space heating and cooling, dehumidifiers and process
chillers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 16905-1:2017 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
4 Test methods
4.1 General
A steady-state or transient or cyclical operation test could be applied for 100 % load tests or for reduced
load tests.
The sound power level is measured in the standard rating conditions as given in EN 16905-3:2017 with
the corresponding test methods according to FprEN 12102-1:2022 considering that this standard,
dedicated to determination of the sound power level could be used with appliances covered in the scope
of EN 16905-1:2017; prEN 16905-2:2021; EN 16905-3:2017 and prEN 16905-5:2021.
Currently in preparation.
Currently in preparation.
Currently in preparation.
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
4.2 Basic principles method of calculation for the determination of capacities
4.2.1 Capacity
4.2.1.1 Measured capacity
The measured cooling or heating capacity of air-to-air or water (brine)-to-air GEHP shall be determined
by measurements in a calorimeter room (see Annex A) or by the air enthalpy method (see Annex B).
The measured cooling or heating capacity of air-to-water (brine) or water (brine)-to-water (brine) GEHP
shall be determined in accordance with the water enthalpy method (see Annex D).
The measured heat recovery capacity of all GEHP shall be determined in accordance with the water
enthalpy method (see Annex D).
4.2.1.2 Effective capacity
4.2.1.2.1 Effective cooling capacity
The effective cooling capacity is the measured cooling capacity corrected for the heat from the device
(pump(s) or fan(s)) responsible for circulating the heat transfer medium through the indoor heat
exchanger:
a) if the fan(s) or pump(s) is (are) an integral part of the appliance, the capacity correction due to the
device, C , calculated according to 4.2.4.3.3.1 or 4.2.4.4.2.1, which is excluded from the total
device-indoor
power input shall be added to the cooling capacity (the correction is positive). The effective heating
capacity shall be determined using the following formula:
Q Q+Abs C (1)
( )
Ec c device _indoor
b) if the fan(s) or pump(s) is (are) not an integral part of the appliance, the capacity correction due to
the device, C , calculated according to 4.2.4.3.3.2 or 4.2.4.4.2.2, which is added to the total
device-indoor
electrical power input shall be subtracted from the cooling capacity (the correction is negative).The
effective cooling capacity shall be determined using the following formula:
Q Q−Abs C (2)
( )
Ec c device _indoor
where:
Q is the effective cooling capacity, in kilowatt;
EC
Q is the measured cooling capacity, in kilowatt;
c
C is the capacity correction due to the device(s) (fan(s) or pump(s)) responsible for
device_indoor
circulating the heat transfer medium through the indoor heat exchanger, in kilowatt.
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oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
4.2.1.2.2 Effective heating capacity
The effective heating capacity is the measured heating capacity corrected for the heat from the device
(pump(s) or fan(s)) responsible for circulating the heat transfer medium through the indoor heat
exchanger:
a) if the fan(s) or pump(s) is (are) an integral part of the appliance, the capacity correction due to the
device, C , calculated according to 4.2.4.3.3.1 or 4.2.4.4.2.1, which is excluded from the total
device_indoor
electrical power input shall also be subtracted from the heating capacity (the correction is negative).
The effective heating capacity shall be determined using the following formula:
Q Q−Abs C (3)
( )
Eh h device _indoor
b) if the fan(s) or pump(s) is (are) not an integral part of the appliance, the capacity correction due to
the device, C , calculated according to 4.2.4.3.3.2 or 4.2.4.4.2.2, which is added to the total
device_indoor
electrical power input shall be also added to the heating capacity (the correction is positive). The
effective heating capacity shall be determined using the following formula:
Q Q+Abs C (4)
( )
Eh h device _indoor
where
Q is the effective heating capacity, in kilowatt;
Eh
Q is the measured heating capacity, in kilowatt;
h
C is the capacity correction due to the device(s) (fan(s) or pump(s)) responsible for
device_indoor
circulating the heat transfer medium through the indoor heat exchanger, in kilowatt.
4.2.1.3 Rating capacity
4.2.1.3.1 Rating cooling capacity
The rating cooling capacity shall be determined using the following formula:
Q
grc
Q=Q×±Abs C (5)
( )
Rc c device _indoor
Q
gmc
where
Q is the rating cooling capacity, in kilowatt;
Rc
Q is the measured cooling capacity, in kilowatt;
c
Q is the rating gas heat input in cooling mode, in kilowatt;
grc
Q is the measured gas heat input in cooling mode, in kilowatt;
gmc
C is the capacity correction due to the device(s) (fan(s) or pump(s)) responsible for
device_indoor
circulating the heat transfer medium through the indoor heat exchanger, in kilowatt.
NOTE For more explanation about the capacity correction due to the device responsible for circulating the heat
transfer medium through the indoor heat exchanger, see 4.2.1.2.1.
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oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
4.2.1.3.2 Rating heating capacity
The rating heating capacity shall be determined using the following formula:
Q
grh
Q=Q×±Abs C (6)
( )
Rh h device _indoor
Q
gmh
where
Q is the rating heating capacity, in kilowatt;
Rh
Q is the measured heating capacity, in kilowatt;
h
Q is the rating gas heat input in heating mode, in kilowatt;
grh
Q is the measured gas heat input in heating mode, in kilowatt;
gmh
C is the capacity correction due to the device(s) (fan(s) or pump(s)) responsible for
device_indoor
circulating the heat transfer medium through the indoor heat exchanger, in kilowatt.
NOTE For more explanation about the capacity correction due to the device responsible for circulating the heat
transfer medium through the indoor heat exchanger, see 4.2.1.2.2.
4.2.2 Engine heat recovery capacity
4.2.2.1 Effective engine heat recovery capacity
The effective engine heat recovery capacity is the measured engine heat recovery capacity corrected for
the heat from the device (pump(s)) of the engine heat recovery circuit (measured in any condition):
a) if this (these) pump(s) is (are) an integral part of the appliance, the capacity correction due to the
pump(s), c , calculated according to 4.2.4.4.2.1 which is excluded from the total electrical power
device_hr
input shall be also subtracted from the engine heat recovery capacity (the correction is negative).
b) if this(these) pump(s) is (are) not an integral part of the appliance, capacity correction due to the
pump(s), c , calculated according to 4.2.4.4.2.2, which is added to the total electrical power
device_hr
input shall be also added to the engine heat recovery capacity (the correction is positive).
The effective engine heat recovery capacity shall be determined using the following formula, which is
applicable to either heating or cooling mode:
Q Q±Abs C (7)
( )
Ehr hr device _hr
where
Q is the effective engine heat recovery capacity, in kilowatt;
Ehr
Q is the measured engine heat recovery capacity, in kilowatt;
hr
C is the capacity correction due to the pump(s) responsible for circulating the heat
device_hr
transfer medium through the engine heat recovery exchanger, in kilowatt.
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oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
4.2.2.2 Rating engine heat recovery capacity in cooling mode
The rating engine heat recovery capacity shall be determined using the following formula:
Q
grhrc
Q =Q×±Abs C (8)
( )
Rhrc hr device _hr
Q
gmhr
where
Q is the rating engine heat recovery capacity in cooling mode, in kilowatt;
Rhrc
Q is the measured engine heat recovery capacity, in kilowatt;
hr
Q is the rating engine heat recovery gas heat input in cooling mode, in kilowatt;
grhrc
Q is the measured engine heat recovery gas heat input, in kilowatt;
gmhr
C is the capacity correction due to the pump(s) responsible for circulating the heat
device_hr
transfer medium through the engine heat recovery heat exchanger, in kilowatt.
NOTE 1 For more explanation about the capacity correction due to the pump(s) responsible for circulating the
heat transfer medium through the engine heat recovery heat exchanger, see 4.2.2.1.
NOTE 2 The rating heat recovery heat input in cooling mode is equal to the rating heat recovery heat input in
heating mode.
4.2.2.3 Rating engine heat recovery capacity in heating mode
The rating engine heat recovery capacity shall be determined using the following formula:
Q
grhrh
Q =Q×±Abs C (9)
( )
Rhrh hr device _hr
Q
gmhr
where
Q is the rating engine heat recovery capacity in heating mode, in kilowatt;
Rhrh
Q is the measured engine heat recovery capacity, in kilowatt;
hr
Q is the rating engine heat recovery gas heat input in heating mode, in kilowatt;
grhrh
Q is the measured engine heat recovery gas heat input, in kilowatt;
gmhr
C is the capacity correction due to the pump(s) responsible for circulating the heat
device_hr
transfer medium through the engine heat recovery heat exchanger, in kilowatt.
NOTE For more explanation about the capacity correction due to the pump(s) responsible for circulating the
heat transfer medium through the engine heat recovery heat exchanger, see 4.2.2.1.
oSIST prEN 16905-4:2022
prEN 16905-4:2022 (E)
4.2.3 Heat input
4.2.3.1 General conditions for operation of the gas-fired part of the appliance
Tests are carried out with the appropriate reference gas(es) for the category to which the appliance
belongs (see EN 437:2021), supplied at the corresponding normal pressure indicated in EN 437:2021.
4.2.3.2 Measurement of heat inputs under test conditions
The appliance is installed as described in prEN 16905-2:2021 and adjusted as described in 4.2.4.1 and
then operated at the heat input imposed by control system of the appliance. The heat input measurement
is carried out when thermal “equilibrium” conditions have been achieved under the particular test
conditions.
NOTE 1 It is important to note that the rating heating, cooling or heat recovery heat input is determined in
accordance with the method given in prEN 16905-2:2021, but that the measured heat input achieved under
particular test conditions is different and determined in a different way. This is described below.
Air pressure at inlet and outlet of the gas engine shall be balanced to avoid under/over pressure of the
gas engine.
The heat input under the test conditions (Q ) in kilowatt is given by the formula:
gm
n
Mc *H
∑ ( j )
iM(T)j
j=1
Q 0,278⋅ (10)
gm
n
or
n
Vc *H
∑ ( j )
iV(T)j
j=1
Q 0,278⋅ (11)
gm
n
where
j is the scan number;
n is the number of scan of the data collection period;
Q is the measured heat input, in kilowatt;
gm
H is the net calorific value of the test gas at the considered scan, in megajoule per kilogram;
iM(T)j
Mc is the mass flow rate of dry test gas at the considered scan, in kilogram per hour;
j
H is the net calorific value of the test gas at the considered scan, in megajoule per cubic
iV(T)j
meter (dry gas, 15 °C, 1 013,25 mbar);
Vc is the volumetric flow rate of dry test gas corrected to 1013,25 mbar and 15 °C at the
j
considered scan, in cubic meter per hour and derived from the following formula:
p +−pj p
288,15
aj wj
Vc=V⋅⋅ (12)
j mj
1013, 25 273,15+t
gj
where
V is the measured gas flow rate at the considered scan, in cubic meter per hour;
mj
p is the atmospheric pressure at the considered scan, in millibar;
aj
pj is the gas supply pressure at the gas meter at the considered scan, in millibar;
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oSIST prEN 16905-4:2022
prEN 16
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