oSIST prEN 304:2023

SLOVENSKI STANDARD
01-marec-2023
Kotli za ogrevanje - Preskušanje kotlov za ogrevanje z razprševalnimi oljnimi
gorilniki
Heating boilers - Test code for heating boilers for atomizing oil burners
Heizkessel - Prüfregeln für Heizkessel mit Ölzerstäubungsbrennern
Chaudières de chauffage - Règles d'essai pour les chaudières avec brûleurs fioul à
pulvérisation
Ta slovenski standard je istoveten z: prEN 304
ICS:
27.060.10 Gorilniki na tekoče in trdo Liquid and solid fuel burners
gorivo
91.140.10 Sistemi centralnega Central heating systems
ogrevanja
97.100.40 Grelniki na tekoče gorivo Liquid fuel heaters
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2023
ICS 91.140.10 Will supersede EN 304:2017
English Version
Heating boilers - Test code for heating boilers for
atomizing oil burners
Chaudières de chauffage - Règles d'essai pour les Heizkessel - Prüfregeln für Heizkessel mit
chaudières avec brûleurs fioul à pulvérisation Ölzerstäubungsbrennern
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 57.
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, Türkiye 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 304:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General conditions for testing . 6
5 Measurement accuracies and uncertainties . 6
6 Measurements for the heating mode . 7
6.1 General . 7
6.2 Determination of the nominal heat output . 7
6.3 Determination of the boiler efficiency at nominal heat output. 8
6.4 Performance of testing . 8
6.4.1 General test conditions . 8
6.4.2 Draught adjustment . 8
6.4.3 Establishment of steady-state conditions . 8
6.4.4 Test period . 8
6.5 Calculation . 8
6.5.1 General . 8
6.5.2 Nominal heat output . 9
6.5.3 Boiler heat input . 9
6.5.4 Boiler efficiency . 9
6.6 Determination of the waterside resistance . 9
6.7 Determination of the standby heat loss . 10
6.7.1 General . 10
6.7.2 Standby heat loss . 10
6.8 Efficiency at 30 % of the nominal heat output . 13
6.8.1 General . 13
6.8.2 Efficiency at 30 % - Method 1 (time dependent method) . 13
6.8.3 Efficiency at 30 % - Method 2 (load dependent method) . 13
6.9 Auxiliary electricity consumption . 15
6.10 Seasonal space heating efficiency . 15
6.11 Verification of nominal condensing output . 15
6.12 Formation of condensation . 15
6.13 Functional test for the temperature sensing control type TR and temperature
sensing control type STB on the boiler . 15
6.14 Surface temperature . 19
6.15 Floor temperatures . 19
6.16 Limiting temperature of the test panels . 19
6.17 Emission values of NO and CO . 20
x
6.17.1 General . 20
6.17.2 Units . 20
6.17.3 Assemblies of a boiler with various burners . 20
7 Measurement of the sanitary water production mode . 21
8 Test report and other documents . 21
Annex A (normative) Calculations for the heating mode . 22
A.1 Volume measurement . 22
A.2 Calculation of combustion parameters . 22
A.3 Determination of air factor (𝜆𝜆) and excess air (e) . 26
A.4 Test rigs . 28
A.5 Calculation of the nominal heat output P . 29
N
A.6 Calculation of the heat input . 30
A.7 Calculation of efficiency . 30
A.8 Calculation of the heat losses q , q , q . 32
A U S
A.9 Standby heat loss (P ) . 35
Stby
A.10 Calculation of the seasonal space heating energy efficiency . 36
A.11 Fuel characteristics . 39
Annex B (informative) Applicable symbols and units . 41
Annex C (informative) Criteria for the adaptation of forced draught burners using liquid
fuels to heating boilers . 44
Annex D (informative) Information for setting up and evaluation of the test rig . 46
Annex E (informative) Determination of the heat losses of the test rig . 47
Annex F (informative) Alternative method for heat output as enthalpy difference. 48
⁠⁠F.1 General . 48
⁠⁠F2 Heat output calculation . 48
⁠⁠F.3 Water enthalpy (Hw) calculation . 49
⁠⁠F.4 Introduction. 49
⁠⁠F.5 Introduction. 50
Annex ZA (informative) Relationship between this European Standard and the ecodesign
requirements of Commission Regulation (EU) No [813/2013] aimed to be covered . 51
Annex ZB (informative) Relationship between this European Standard and the ecodesign
requirements of Commission Delegated Regulation (EU) No [811/2013] aimed to be
covered . 52
Bibliography . 53
European foreword
This document (prEN 304:2023) has been prepared by Technical Committee CEN/TC 57 “Central
heating boilers”, the secretariat of which is held by DIN.
This document will supersede EN 304:2017.
For relationship with EU Directive(s), see informative Annexes ZA and ZB, which are an integral part of
this document.
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 Annexes ZA and ZB, which is an
integral part of this document.
The main technical changes compared to EN 303-2:2017 are the following:
a) new Annex F for calculation clarification was added;
b) new clause marking and instructions was added;
c) updated Normati
...