SIST EN 12309-6:2025

SLOVENSKI STANDARD
01-september-2025
Nadomešča:
SIST EN 12309-6:2015
Absorpcijske in adsorpcijske plinske naprave za gretje in/ali hlajenje z grelno
močjo do vključno 70 kW - 6. del: Izračun sezonske zmogljivosti
Gas-fired sorption appliances for heating and/or cooling with a net heat input not
exceeding 70 kW - Part 6: Calculation of seasonal performances
Gasbefeuerte Sorptions-Geräte für Heizung und/oder Kühlung mit einer
Nennwärmebelastung nicht über 70 kW - Teil 6: Berechnung der saisonalen
Effizienzkennzahlen
Appareils à sorption fonctionnant au gaz pour le chauffage et/ou le refroidissement de
débit calorifique sur PCI inférieur ou égal à 70 kW - Partie 6 : Calcul des performances
saisonnières
Ta slovenski standard je istoveten z: EN 12309-6:2025
ICS:
27.080 Toplotne črpalke Heat pumps
91.140.30 Prezračevalni in klimatski Ventilation and air-
sistemi conditioning systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 12309-6
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2025
EUROPÄISCHE NORM
ICS 27.080; 91.140.30 Supersedes EN 12309-6:2014
English Version
Gas-fired sorption appliances for heating and/or cooling
with a net heat input not exceeding 70 kW - Part 6:
Calculation of seasonal performances
Appareils à sorption fonctionnant au gaz pour le Gasbefeuerte Sorptions-Geräte für Heizung und/oder
chauffage et/ou le refroidissement de débit calorifique Kühlung mit einer Nennwärmebelastung nicht über 70
sur PCI inférieur ou égal à 70 kW - Partie 6 : Calcul des kW - Teil 6: Berechnung der saisonalen
performances saisonnières Effizienzkennzahlen
This European Standard was approved by CEN on 24 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
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member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
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COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

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© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12309-6:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
1 Scope . 5
1.1 Scope of EN 12309 . 5
1.2 Scope of this Part 6 to EN 12309 . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Calculation methods for reference SGUE and SAEF in cooling mode . 6
4.1 General. 6
4.2 Part load conditions . 6
4.2.1 General. 6
4.2.2 Air-to-water appliances . 7
4.2.3 Water-to-water and brine-to-water appliances . 7
4.3 Calculation of reference SGUEc . 8
4.4 Calculation of reference SAEFc . 9
4.5 Calculation of reference annual cooling demand (Q ) . 9
refc
4.6 Calculation of reference SAEFc . 9
on
4.7 Procedures for the determination of GUEc / AEFc values . 10
5 Calculation methods for reference seasonal performance in heating mode . 10
5.1 General. 10
5.2 Part load conditions . 11
5.2.1 General. 11
5.2.2 Air-to-water appliances . 12
5.2.3 Water-to-water and brine-to-water appliances . 15
5.3 Calculation of reference SPERh . 18
5.4 Calculation of reference SGUEh . 18
5.5 Calculation of reference SAEFh . 20
5.6 Calculation of reference annual heating demand (Q ) . 21
refh
5.7 Calculation of reference SAEFh . 21
on
5.8 Procedures for the determination of GUEh / AEFh values . 22
Annex A (informative) Calculation example for reference SGUEc and SAEFc . 23
Annex B (informative) Calculation example for reference SGUEh, SAEFh and SPERh . 25
Annex C (normative) Number of hours in thermostat off mode, stand-by mode and off mode
for reference SAEFc and SAEFh calculation . 27
Annex D (normative) Calculation of the reference seasonal performance in heating mode for
bivalent appliances . 31
D.1 General. 31
D.2 Determination of supplementary heater efficiency and heating capacity . 31
D.3 Determination of GUEh and AEFh . 32
D.4 Seasonal performance figures for the bivalent appliance as a whole . 33
D.5 Seasonal performance figures for the sole heat pumps appliance during active mode
................................................................................................................................................................... 35
Annex E (normative) Procedures for the determination of GUEh, AEFh and SAEFh value with
multiple identical heat pumps . 37
E.1 General . 37
E.2 Calculation procedure for GUEh and AEFh for fixed capacity heat pumps. 37
E.3 Calculation procedure for GUEh and AEFh for variable capacity heat pumps . 38
E.4 Calculation procedure for SAEFh . 39
Annex F (normative) Calculation of seasonal space heating energy efficiency for monovalent
or bivalent gas-driven sorption heat pump based heating appliances . 40
Annex ZA (informative) Relationship between this European Standard and the ecodesign
requirements of Commission Regulation (EU) No 813/2013 of 2 August 2013 [OJEU L
239/136, 6.9.2013] aimed to be covered . 43
Annex ZB (informative) Relationship between this European Standard and the energy
labelling requirements of Commission Delegated Regulation (EU) No 811/2013 of 18
February 2013 [OJEU L 239/1, 6.9.2013] aimed to be covered . 44
Bibliography . 45
European foreword
This document (EN 12309-6:2025) 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 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 October 2025, and conflicting national standards shall
be withdrawn at the latest by October 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 12309-6:2014.
— terminology has been aligned to Commission Regulation (EU) No 813/2013 of 2 August 2013 and
Commission Delegated Regulation (EU) No 811/2013 of 18 February 2013;
— heating temperature profile 45 °C has been eliminated;
— optional testing points have been added.
This document comprises parts under the general title, Gas-fired sorption appliances for heating and/or
cooling with a net heat input not exceeding 70 kW. A list of all parts in a series can be found on the CEN
website.
This document will be reviewed whenever new mandates could apply.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
For the relationship with EU Legislation, see informative Annexes ZA and ZB, which are integral parts of
this document.
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.
1 Scope
1.1 Scope of EN 12309
Appliances covered by this document include one or a combination of the following:
— gas-fired sorption chiller;
— gas-fired sorption chiller/heater;
— gas-fired sorption heat pump.
This document applies to appliances designed to be used for space heating or cooling or refrigeration
with or without heat recovery.
This document applies to appliances having flue gas systems of Type B and Type C (according to
EN 1749:2020) and to appliances designed for outdoor installations, including Type A. EN 12309 does
not apply to air conditioners, it only applies to appliances having:
— integral burners under the control of fully automatic burner control systems,
— closed system refrigerant circuits in which the refrigerant does not come into direct contact with the
water or air to be cooled or heated,
— mechanical means to assist transportation of the combustion air and/or the flue gas.
The above appliances can have one or more primary or secondary functions (i.e. heat recovery - see
definitions in EN 12309-1:2023).
In the case of packaged units (consisting of several parts), this document applies only to those designed
and supplied as a complete package.
The appliances having their condenser cooled by air and by the evaporation of external additional water
are not covered by EN 12309.
Installations used for heating and/or cooling of industrial processes are not within the scope of EN 12309.
All the symbols given in this document are used regardless of the language used.
1.2 Scope of this Part 6 to EN 12309
This part of EN 12309 specifies the calculation methods of seasonal performances for gas-fired sorption
appliances for heating and/or cooling with a net heat input not exceeding 70 kW. It deals in particular
with the calculation methods of reference seasonal performances in cooling and heating mode for
monovalent and bivalent appliances.
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 12309-1:2023, Gas-fired sorption appliances for heating and/or cooling with a net heat input not
exceeding 70 kW — Part 1: Terms and definitions
EN 12309-3:2024, Gas-fired sorption appliances for heating and/or cooling with a net heat input not
exceeding 70 kW — Part 3: Requirements, test conditions and test methods
EN 15502-1:2021+A1:2023, Gas-fired heating boilers — Part 1: General requirements and tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12309-1:2023 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
4 Calculation methods for reference SGUE and SAEF in cooling mode
4.1 General
The calculation of the reference Seasonal Gas Utilization Efficiency ratio in cooling mode (SGUEc) and
reference Seasonal Auxiliary Energy factor in cooling mode (SAEFc) follows from the application of the
bin method, where the part load Gas Utilization Efficiency ratio in cooling mode (GUEc) and Auxiliary
Energy Factor in cooling mode (AEFc) at each bin temperature is determined via linear interpolation of
the respective part load values at the reference part load conditions A, B, C and D.
The part load conditions A, B, C, D provide the part load ratios and the temperature test conditions at four
reference outdoor air dry bulb temperatures: 35 °C, 30 °C, 25 °C and 20 °C.
The part load ratio corresponding to a given outdoor temperature T is defined according to Formula (1):
j
PLRc Tj=Tj− 16 / 35− 16 (1)
( ) ( ) ( )
At part load condition A, the declared capacity of the appliance is assumed equal to the building load (i.e.
capacity ratio = 100 %).
At part load conditions B, C and D, the declared capacity of the appliance is higher than the building load.
The capacity ratio (CR), i.e. the ratio of the cooling load (P ) over the declared capacity (DC) of the
c
appliance at the same temperature conditions, is lower than one. In such conditions, the GUEc and AEFc
are affected by both temperature test conditions and capacity ratio. The methods for the determination
of GUEc and AEFc are defined in EN 12309-3:2024.
4.2 Part load conditions
4.2.1 General
For the indoor heat exchanger both fan coil and floor cooling applications are considered.
For the fan coil application, appliances which do, and do not, allow variations of the outlet water
temperature with the outdoor temperature are considered. Variable outlet temperatures shall only be
applied when the programming unit provides an outdoor air temperature dependent modification of the
outlet temperature.
4.2.2 Air-to-water appliances
Table 1 — Part load conditions for the seasonal performance calculation in cooling mode of air-
to-water appliances
Outdoor heat
Indoor heat exchanger
exchanger
Fan coil application Floor cooling
application
Inlet/outlet water temperatures
Part load ratio
Air dry bulb
Inlet/outlet
°C
temperature
water
°C
temperatures
Fixed outlet Variable outlet
°C
A 1 35 12 / 7 12 / 7 23 / 18
a a a
B (30–16) / (35–16) 30 / 7 / 8,5 / 18
a a a
C (25–16) / (35–16) 25 / 7 / 10 / 18
a a a
D (20–16) / (35–16) 20 / 7 / 11,5 / 18
a
With the water flow rate as determined during standard rating test with a fixed water flow rate.
4.2.3 Water-to-water and brine-to-water appliances
Table 2 — Part load conditions for the seasonal performance calculation in cooling mode of
water-to-water appliances and brine to water appliances
Outdoor heat exchanger Indoor heat exchanger
Ground Fan coil
coupled application
Cooling tower Dry cooler Floor cooling
application
Inlet/outlet water
application application application
Part load (water or
temperatures
Inlet/outlet Inlet/outlet Inlet/outlet
ratio brine)
°C
water water water
Inlet/outlet
temperatures temperatures
temperatures
water
Fixed Variable
°C °C °C
temperatures
outlet outlet
°C
A 1 30 / 35 10 / 15 50 / 55 12 / 7 12 / 7 23 / 18
(30–
a a a a a a
B 16) / (35 26 / 10 / 45 /  / 7 / 8,5 / 18
–16)
(25–
a a a a a a
C 16) / (35 22 / 10 / 40 /  / 7 / 10 / 18
–16)
(20–
a a a a a a
D 16) / (35 18 / 10 / 35 /  / 7 / 11,5 / 18
–16)
a
With the water flow rate as determined during standard rating test with a fixed water flow rate.
4.3 Calculation of reference SGUEc
The calculation of the reference Seasonal Gas Utilization Efficiency ratio in cooling mode (SGUEc) that
applies to all types of appliances is given by Formula (2):
n
h × PT
( )
∑ j cj
j=1
SGUEc= (2)
PT
n ( )
cj
h ×
j
∑
j=1
GUEc T
( )
j
where
T is the bin temperature;
j
j is the bin number;
n is the number of bins;
P (T ) is the cooling load of the building not exceeding the appliance declared capacity at the
c j
corresponding temperature T ;
j
h is the number of bin hours occurring at the corresponding temperature T ;
j j
GUEc(T ) is the GUEc of the appliance for the corresponding temperature T .
j j
The values to be used for j, T and h are determined in Table 3.
j j
Table 3 — bin number j, outdoor bin temperature T in °C and number of hours per bin h
j j
corresponding to the reference cooling season
j (#) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Tj (°C) 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
hj (h) 205 227 225 225 216 215 218 197 178 158 137 109 88 63 39 31 24 17 13 9 4 3 1 0
The cooling load that is not exceeding the appliance declared capacity is determined by multiplying the
full load value (P ) with the part load ratio PLR (T ) of the corresponding bin:
design,c c j
P T P × PLR T (3)
( ) ( )
cj design,c c j
where PLR (T ) is:
c j
— defined according to Formula (1) for T less than or equal to 35 °C;
j
— always 1 for T greater than 35 °C.
j
The GUEc values at each bin are determined via interpolation of the GUEc values at part load conditions A,
B, C and D as defined in 4.1.
For part load conditions above part load condition A, the same GUEc values as for condition A shall be
used.
For part load conditions below part load condition D, the same GUEc values as for condition D shall be
used.
=
4.4 Calculation of reference SAEFc
The calculation of the reference Seasonal Auxiliary Energy Factor in cooling mode (SAEFc) that applies to
all types of appliances is given by reference annual cooling demand divided by the annual electricity
consumption.
The annual electricity consumption includes the power consumption during active mode, thermostat off
mode, standby mode and off mode.
Q
refc
SAEFc=  (4)
Q
refc
+ H × P + H ×+PH × P
TO TO SB SB OFF OFF
SAEFc
on
where
Q is the reference annual cooling demand, expressed in kWh, as defined in 4.5;
refc
SAEFc is the Seasonal Auxiliary Energy Factor in cooling mode and active mode, as
on
defined in 4.6;
H , H , H are the number of hours the appliance is considered to work in respectively
TO SB OFF
thermostat off mode, standby mode and off mode. The number of hours to be used
for cooling is indicated in Annex C;
P , P , P are the electricity consumption during respectively thermostat off mode, standby
TO SB OFF
mode and off mode, expressed in kW. The measurement of P , P , P shall be
TO SB OFF
made according to EN 12309-3:2024.
4.5 Calculation of reference annual cooling demand (Qrefc)
The reference annual cooling demand is expressed in kWh and can be calculated as the design cooling
load (P ) multiplied by the number of equivalent cooling hours (H ):
design,c ec
Q P × H (5)
refc design,c ec
The number of equivalent cooling hours (H ) can be found in Annex C.
ec
4.6 Calculation of reference SAEFc
on
The reference SAEFc is determined as follows:
on
n
h × PT
( )
∑ jjc
j=1
(6)
SAEFc =
on
P T
n ( )
c j
h ×
j
∑
j=1
AEFc T
( )
j
where
T is the bin temperature;
j
j is the bin number;
n is the number of bin;
P (T ) is the cooling load of the building for the corresponding temperature Tj;
c j
h is the number of bin hours occurring at the corresponding temperature Tj;
j
=
AEFc(T ) is the AEFc values of the appliance for the corresponding temperature Tj.
j
The values to be used for j, T and hj are determined in Table 3.
j
The cooling load P (T ) shall be determined according to Formula (3).
c j
The AEFc values at each bin are determined via interpolation of the AEFc values at part load conditions
A, B, C and D as defined in 4.1.
For part load conditions above part load condition A, the same AEFc values as for condition A shall be
used.
For part load conditions below part load condition D, the same AEFc values as for condition D shall be
used.
4.7 Procedures for the determination of GUEc / AEFc values
In part load condition A (full load), the declared capacity of an appliance is considered equal to the cooling
load (P ). Accordingly, the test methods at full capacity shall be used, as defined in EN 12309-3:2024.
design,c
In part load conditions B, C, D, the test methods at reduced capacity shall be used, as defined in
EN 12309-3:2024.
5 Calculation methods for reference seasonal performance in heating mode
5.1 General
For the purpose of calculating the reference seasonal performance in heating mode, three reference
climatic conditions are defined: average (A), warmer (W) and colder (C).
The relevant reference design outdoor temperature for heating (T ) and bivalent temperature
design,h
(T ) values are set as follows:
bivalent
Table 4 — Design temperature and bivalent temperature upper limit for the different reference
heating seasons
Dry bulb temperature conditions
Reference Heating
Season
T T upper limit
design,h bivalent
Average (A) −10 °C 2 °C
Warmer (W) +2 °C +7 °C
Colder (C) −22 °C −7 °C
For bivalent appliances, T can be any value between T and the T upper limit. Once T
bivalent design,h bivalent bivalent
is defined in dry bulb, the corresponding wet bulb temperature shall be calculated as dry bulb
temperature minus 1 K. For monovalent appliances, T shall be assumed equal to T .
bivalent design,h
For air to water appliances, the declared Operation Limit Temperature (TOL) of the heat pump appliance
shall also be considered. TOL higher than T is an acceptable condition only for bivalent appliances.
design,h
If TOL is lower than T , TOL is not taken into account for the calculation of the seasonal performance
design,h
and it can be assumed equal to T .
design,h
The calculation of the seasonal performance follows from the application of the bin method, where the
part load Gas Utilization Efficiency ratio in heating mode (GUEh) and Auxiliary Energy Factor in heating
mode (AEFh) at each bin temperature is determined via linear interpolation of the respective part load
values at the reference part load conditions A, B, C, D, E, F and G.
The part load conditions A, B, C, D and G provide the part load ratios and the temperature test conditions
at five reference outdoor air dry bulb temperatures: −7 °C, +2 °C, +7 °C, +12 °C and −15 °C.
The part load conditions E and F provide the part load ratios and temperature test conditions at the
appliance operation limit outdoor temperature (TOL) and at the appliance bivalent outdoor temperature
(T ), respectively.
bivalent
Optional test conditions at outdoor air dry bulb temperatures T different from A, B, C, D, E, F and G can
j
be measured; inlet/outlet temperatures shall be determined via linear interpolation between the two
closest reference part load conditions A, B, C, D, E, F and G. Optional testing points, if used for the
calculation of seasonal performance, shall be declared.
The part load ratio corresponding to a given outdoor temperature T is defined according to Formula (7):
j
PLRh T=T− 16 / T − 16 (7)
( ) ( ) ( )
jj design,h
At part load conditions for which the outdoor temperature is lower than or equal to the defined T
bivalent
temperature, the appliance declared capacity is lower than or equal to the requested heating load. In this
condition, the appliance operates at its maximum capacity and the gap between heating load and
appliance declared capacity is covered by a supplementary heater. The GUEh and AEFh at full capacity
are to be used.
At the T part load condition (F), the appliance’s declared capacity is equal to the requested heating
bivalent
load. In this condition, the appliance operates at its maximum capacity and the supplementary heater (if
any) is turned off. The GUEh and AEFh at full capacity are to be used.
At any other part load conditions, the declared capacity of the appliance is larger than the building load.
Accordingly, the supplementary heater (if any) is turned off and the appliance capacity ratio (CR), i.e. the
) over the declared capacity (DC) of the appliance at the same temperature
ratio of the heating load (Ph
conditions, is lower than 1. The GUEh and AEFh are affected by both temperature test conditions and
capacity ratio. The methods for the determination of GUEh and AEFh are defined in EN 12309-3:2024.
When the heat pump appliance is constituted by two or more identical heat pumps, the methods for the
determination of GUEh and AEFh specified in Annex E shall be used.
5.2 Part load conditions
5.2.1 General
The part load conditions for each type of appliance (air-to-water, water-to-water and brine-to water),
reference heating season (average, warmer, colder) and application temperatures (low temperature,
medium temperature, high temperature) are given in the following tables.
Appliances which either allow a variation of the outlet water temperature with the outdoor temperature
or do not are both considered. The variable outlet temperature test point scheme in the following tables
shall only be applied when the programming unit provides an outdoor air temperature dependent
modification of the outlet temperature.
5.2.2 Air-to-water appliances
5.2.2.1 Low temperature application
Table 5 — Part load conditions for reference seasonal performance calculation in heating mode
of air-to-water appliances for low temperature application for the reference heating season
“A” = average, “W” = warmer and “C” = colder
Outdoor heat
Indoor heat exchanger
exchanger
Part load ratio
Inlet dry (wet Fixed Variable outlet
%
bulb) temperature outlet
Inlet / outlet
°C °C temperatures °C
Outdoor Exhaust
Formula A W C All Climates A W C
air air
(T −16) /
design,h
c a a a a
T 100 100 100 T ( ) 20(12) / 35 / 35 / 35 / 35
design,h design,h
(Tdesign,h −16)
(−7–16) /
a a a
A 88 n/a 61 −7(−8) 20(12) / 35 / 34 n/a / 30
(Tdesign,h −16)
(+2–16) /
a a a
B 54 n/a 37 2(1) 20(12) / 35 / 30 n/a / 27
(Tdesign,h −16)
(+7–16) /
a a a a
C 35 64 24 7(6) 20(12) / 35 / 27 / 31 / 25
(Tdesign,h −16)
(+12–16) /
a a a a
D 15 29 11 12(11) 20(12) / 35 / 24 / 26 / 24
(Tdesign,h −16)
c a a b a b a b
E (TOL−16) / (Tdesign,h −16) TOL ( ) 20(12) / 35 / / /
c a a b a b a b
F (T −16) / (T −16) T ( ) 20(12) / 35 / / /
bivalent design,h bivalent
(−15–16) /
c a a
G n/a n/a 82 −15 ( ) 20(12) / 35 n/a n/a / 32
−16)
(Tdesign,h
a
With the water flow rate as determined at standard rating test conditions for low temperature applications given in
EN 12309-3:2024 for appliances with a fixed water flow rate, or with the flow rate defined and set by the appliance
controller for an appliance using a variable water flow rate, provided the condition on ΔTmax set in EN 12309-3:2024, 5.2
is matched.
b
Variable outlet shall be calculated by interpolation between the outlet temperatures of the upper and lower reference
testing points which are closest to the TOL or bivalent temperature.
c
For outdoor air dry bulb temperatures higher or equal to −10 °C the wet bulb temperature equals the dry bulb
temperature minus 1 K. For dry bulb temperatures below −10 °C, the wet bulb temperature is not defined.
Condition
5.2.2.2 Medium temperature application
Table 6 — Part load conditions for reference seasonal performance calculation in heating mode
of air-to-water appliances for medium temperature application for the reference heating season
“A” = average, “W” = warmer and “C” = colder
Outdoor heat
Indoor heat exchanger
exchanger
Part load ratio
Inlet dry (wet Variable outlet
% Fixed outlet
bulb) temperature
Inlet / outlet
°C
°C temperatures °C
Outdoor Exhaust
Formula A W C All Climates A W C
air air
(Tdesign,h −16) /
c a a a a
Tdesign,h 100 100 100 Tdesign,h ( ) 20(12) / 55 / 55 / 55 / 55
(T −16)
design,h
(−7–16) /
a a a
A 88 n/a 61 −7(−8) 20(12) / 55 / 52 n/a / 44
(T −16)
design,h
(+2–16) /
a a a
B 54 n/a 37 2(1) 20(12) / 55 / 42 n/a / 37
(T −16)
design,h
(+7–16) /
a a a a
C 35 64 24 7(6) 20(12) / 55 / 36 / 46 / 32
(T −16)
design,h
(+12–16) /
a a a a
D 15 29 11 12(11) 20(12) / 55 / 30 / 34 / 28
(T −16)
design,h
c a a b a b a b
E (TOL−16) / (T −16) TOL ( ) 20(12) / 55 / / /
design,h
c a a b a b a b
F (Tbivalent − 16) / (Tdesign,h −16) Tbivalent ( ) 20(12) / 55 / / /
(−15–16) /
c a a
G n/a n/a 82 −15 ( ) 20(12) / 55 n/a n/a / 49
(T −16)
design,h
a
With the water flow rate as determined at standard rating test conditions for medium temperature applications given in
EN 12309-3:2024 for appliances with a fixed water flow rate, or with the flow rate defined and set by the appliance
controller for an appliance using a variable water flow rate, provided the condition on ΔT set in EN 12309-3:2024, 5.2
max
is matched.
b
Variable outlet shall be calculated by interpolation between the outlet temperatures of the upper and lower reference
testing points which are closest to the TOL or bivalent temperature.
c
For outdoor air dry bulb temperatures higher or equal to −10 °C the wet bulb temperature equals the dry bulb
temperature minus 1 K. For dry bulb temperatures below −10 °C, the wet bulb temperature is not defined.
Condition
5.2.2.3 High temperature application
Table 7 — Part load conditions for reference seasonal performance calculation in heating mode
of air-to-water appliances for high temperature application for the reference heating season
“A” = average, “W” = warmer and “C” = colder
Outdoor heat
Indoor heat exchanger
exchanger
Part load ratio
Inlet dry (wet
Variable outlet
%
bulb) Fixed outlet
Inlet / outlet
temperature
°C
temperatures °C
°C
Outdoor Exhaust
Formula A W C All Climates A W C
air air
(T −16) /
design,h
Tdesign,h
a a a a
Tdesign,h 100 100 100 20(12) / 65 / 65 /65 / 65
c
)
(
(Tdesign,h −16)
(−7–16) /
a a a
A 88 n/a 61 −7(−8) 20(12) / 65 / 61 n/a / 50
(Tdesign,h −16)
(+2–16) /
a a a
B 54 n/a 37 2(1) 20(12) / 65 / 49 n/a / 41
(Tdesign,h −16)
(+7–16) /
a a a a
C 35 64 24 7(6) 20(12) / 65 / 41 / 53 / 36
(Tdesign,h −16)
(+12–16) /
a a a a
D 15 29 11 12(11) 20(12) / 65 / 32 / 39 / 30
(Tdesign,h −16)
c a a b a b a b
E (TOL−16) / (T −16) TOL ( ) 20(12) / 65 / / /
design,h
Tbivalent
a a b a b a b
F (Tbivalent −16) / (Tdesign,h −16) 20(12) / 65 / / /
c
( )
(−15–16) /
c a a
G n/a n/a 82 −15 ( ) 20(12) / 65 n/a n/a / 57
(Tdesign,h −16)
a
With the water flow rate as determined at standard rating test conditions for high temperature applications given in
EN 12309-3:2024 for appliances with a fixed water flow rate, or with the flow rate defined and set by the appliance
controller for an appliance using a variable water flow rate, provided the condition on ΔTmax set in EN 12309-3:2024, 5.2
is matched.
b
Variable outlet shall be calculated by interpolation between the outlet temperatures of the upper and lower reference
testing points which are closest to the TOL or bivalent temperature.
c
For outdoor air dry bulb temperatures higher or equal to −10 °C the wet bulb temperature equals the dry bulb
temperature minus 1 K. For dry bulb temperatures below −10 °C, the wet bulb temperature is not defined.
Condition
5.2.3 Water-to-water and brine-to-water appliances
5.2.3.1 Low temperature application
Table 8 — Part load conditions for reference seasonal performance calculation in heating mode
of water/brine-to-water appliances for low temperature application for the reference heating
season “A” = average, “W” = warmer and “C” = colder
Outdoor heat
Indoor heat exchanger
exchanger
Part load ratio
Inlet / outlet Fixed Variable outlet
%
temperatures outlet
Inlet / outlet
°C °C temperatures °C
Ground
Formula A W C Brine All Climates A W C
water
(T −16) /
design,h
c c a a a a
T 100 100 100 10 / 0 /  / 35 / 35 / 35 / 35
design,h
(Tdesign,h −16)
(−7–16) /
c c a a a
A 88 n/a 61 10 / 0 /  / 35 / 34 n/a / 30
(Tdesign,h −16)
(+2–16) /
c c a a a
B 54 n/a 37 10 / 0 /  / 35 / 30 n/a / 27
(Tdesign,h −16)
(+7–16) /
c c a a a a
C 35 64 24 10 / 0 /  / 35 / 27 / 31 / 25
(Tdesign,h −16)
(+12–16) /
c c a a a a
D 15 29 11 10 / 0 /  / 35 / 24 / 26 / 24
(Tdesign,h −16)
c c a a b a b a b
F (Tbivalent −16) / (Tdesign,h −16) 10 / 0 /  / 35 / / /
(−15–16) /
c c a a
G n/a n/a 82 10 / 0 /  / 35 n/a n/a / 32
(T −16)
design,h
a
With the water flow rate as determined at standard rating test conditions for low temperature applications given in
EN 12309-3:2024 for appliances with a fixed water flow rate, or with the flow rate defined and set by the appliance controller
for an appliance using a variable water flow rate, provided the condition on ΔT set in EN 12309-3:2024, 5.2 is matched.
max
b
Variable outlet shall be calculated by interpolation between the outlet temperatures of the upper and lower reference testing
points which are closest to the bivalent temperature.
c
With the water/brine flow rate corresponding to the inlet and outlet temperature given in EN 12309-3:2024 at standard
rating test conditions for low temperature applications.
Condition
5.2.3.2 Medium temperature application
Table 9 — Part load conditions for reference seasonal performance calculation in heating mode
of water to water and brine-to-water appliances for medium temperature application for the
reference heating season “A” = average, “W” = warmer and “C” = colder
Outdoor heat
Indoor heat exchanger
exchanger
Part load ratio
Inlet / outlet Fixed Variable outlet
%
temperatures outlet
Inlet / outlet
°C °C temperatures °C
Ground
Formula A W C Brine All Climates A W C
water
(Tdesign,h −16) /
c c a a a a
Tdesign,h 100 100 100 10 / 0 /  / 55 / 55 / 55 / 55
(T −16)
design,h
(−7–16) /
c c a a a
A 88 n/a 61 10 / 0 /  / 55 / 52 n/a / 44
(T −16)
design,h
(+2–16) /
c c a a a
B 54 n/a 37 10 / 0 /  / 55 / 42 n/a / 37
(T −16)
design,h
(+7–16) /
c c a a a a
C 35 64 24 10 / 0 /  / 55 / 36 / 46 / 32
(T −16)
design,h
(+12–16) /
c c a a a a
D 15 29 11 10 / 0 /  / 55 / 30 / 34 / 28
(T −16)
design,h
c c a a b a b a b
F (T −16) / (T −16) 10 / 0 /  / 55 / / /
bivalent design,h
(−15–16) /
c c a a
G n/a n/a 82 10 / 0 /  / 55 n/a n/a / 49
(T −16)
design,h
a
With the water flow rate as determined at standard rating test conditions for medium temperature applications given in
EN 12309-3:2024 for appliances with a fixed water flow rate, or with the flow rate defined and set by the appliance controller
for an appliance using a variable water flow rate, provided the condition on ΔTmax set in EN 12309-3:2024, 5.2 is matched.
b
Variable outlet shall be calculated by interpolation between the outlet temperatures of the upper and lower reference testing
points which are closest to the bivalent temperature.
c
With the water/brine flow rate corresponding to the inlet and outlet temperature given in EN 12309-3:2024 at standard
rating test conditions for medium temperature applications.
Condition
5.2.3.3 High temperature application
Table 10 — Part load conditions for reference seasonal performance calculation in heating
mode of water to water and brine-to-water appliances for high temperature application for the
reference heating season “A” = average, “W” = warmer and “C” = colder
Outdoor heat
Indoor heat exchanger
exchanger
Part load ratio
Inlet / outlet Fixed Variable outlet
%
temperatures outlet
Inlet / outlet
°C °C temperatures °C
Ground
Formula A W C Brine All Climates A W C
water
(Tdesign,h −16) /
c c a a a a
Tdesign,h 100 100 100 10 / 0 /  / 65 / 65 /65 / 65
(T −16)
design,h
(−7–16) /
c c a a a
A 88 n/a 61 10 / 0 /  / 65 / 61 n/a / 50
(T −16)
design,h
(+2–16) /
c c a a a
B 54 n/a 37 10 / 0 /  / 65 / 49 n/a / 41
(T −16)
design,h
(+7–16) /
c c a a a a
C 35 64 24 10 / 0 /  / 65 / 41 / 53 / 36
(T −16)
design,h
(+12–16) /
c c a a a a
D 15 29 11 10 / 0 /  / 65 / 32 / 39 / 30
(T −16)
design,h
c c a a b a b a b
F (T −16) / (T −16) 10 / 0 /  / 65 / / /
bivalent design,h
(−15–16) /
c c a a
G n/a n/a 82 10 / 0 /  / 65 n/a n/a / 57
(Tdesign,h −16)
a
With the water flow rate as determined at standard rating test conditions for high temperature applications given in
EN 12309-3:2024 for appliances with a fixed water flow rate, or with the flow rate defined and set by the appliance controller
for an appliance using a variable water flow rate, provided the condition on ΔTmax set in EN 12309-3:2024, 5.2 is matched.
b
Variable outlet shall be calculated by interpolation between the outlet temperatures of the upper and lower reference testing
points which are closest to the bivalent temperature.
c
With the water/brine flow rate corresponding to the inlet and outlet temperature given in EN 12309-3:2024 at standard
rating test conditions for high temperature applications.
Condition
5.3 Calculation of reference SPERh
The Seasonal Primary Energy Ratio in heating mode (SPERh) is determined according to Formula (8):
SPERh= (8)
Prim
Prim
gas
elec
+
SGUEh SAEFh
where
Prim is the primary energy factor for gas, by default equal to 1 on GCV unless differently declared;
gas
Prim is the primary energy factor for electricity, by default equal to 2,5 unless differently
elec
declared;
SGUEh is the seasonal gas utilization efficiency in heating mode, as defined in 5.4;
SAEFh is the seasonal auxiliary energy factor in heating mode, as defined in 5.5.

The calculation of the seasonal space heating energy efficiency η follows from the calculation of SPERh
s
as specified in Annex F.
5.4 Calculation of reference SGUEh
The reference SGUEh for monovalent appliances is determined as follows:
n
h × P T
( )
jjh
∑
j=1
(9)
SGUEh=

P T
n ( )
h j

h ×
j 
∑
j=1
GUEh T
( )
j

where
T is the bin temperature;
j
j is the bin number;
n is the number of bins;
P (T ) is the heating load of the building for the corresponding temperature T , expressed in kW;
h j j
h is the number of bin hours occurring at the corresponding temperature T ;
j j
GUEh (T ) is the GUEh values of the appliance for the corresponding temperature T .
j j
The values to be used for j, T and h are determined in Table 11.
j j
The reference SGUEh for bivalent appliances shall be determined as specified in Annex D.
Table 11 — bin number j, outdoor temperature T in °C and number of hours per bin h
j j
corresponding to the reference heating seasons “Warmer”, “Average”, “Colder”
Warmer (W) Average (A) Colder (C)
j T h h h
j jW jA jC
# °C h h h
1 to 8 −30 to −23 0 0 0
9 −22 0 0 1
10 −21 0 0 6
11 −20 0 0 13
12 −19 0 0 17
13 −18 0 0 19
14 −17 0 0 26
15 −16 0 0 39
16 −15 0 0 41
17 −14 0 0 35
18 −13 0 0 52
19 −12 0 0 37
20 −11 0 0 41
21 −10 0 1 43
22 −9 0 25 54
23 −8 0 23 90
24 −7 0 24 125
25 −6 0 27 169
26 −5 0 68 195
27 −4 0 91 278
28 −3 0 89 306
29 −2 0 165 454
30 −1 0 173 385
31 0 0 240 490
32 1 0 280 533
33 2 3 320 380
34 3 22 357 228
35 4 63 356 261
36 5 63 303 279
37 6 175 330 229
---------------------- Pa
...