ISO 24365:2022

INTERNATIONAL ISO
STANDARD 24365
First edition
2022-08
Radiators and convectors — Methods
and rating for determining the heat
output
Reference number
© ISO 2022
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ii
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and units . 1
3.1 Terms and definitions . 1
3.2 Symbols and units of measurement. 4
4 Selection of heating appliances to be tested . 5
4.1 Classification . 5
4.2 Selection of models to be tested for determining the thermal outputs of a type . 6
4.2.1 Selection of models to be tested when the variable characteristic dimension
is the overall height and the cross-section of the variable part is constant . 6
4.2.2 Selection of models to be tested when the variable characteristic dimension
for the type is other than the overall height . 7
4.3 Testing samples submission and identification . 8
4.4 Supplementary test . 11
5 Laboratory equipment and test methods .11
5.1 Principle . 11
5.2 Apparatus . 11
5.2.1 Test system . 11
5.2.2 Reference test installation . 11
5.2.3 Master radiators . 14
5.2.4 Verification of test installation repeatability and reproducibility . 18
5.2.5 Accuracy of measuring instruments and devices .23
5.2.6 Calibration of measuring instruments . 24
5.3 Preparation for thermal output test. 24
5.4 Test methods . 24
5.4.1 General . 24
5.4.2 Weighing method . 24
5.4.3 Electric method . 25
5.4.4 Measurements and calculations . 25
5.4.5 Determination of the characteristic equation .28
5.5 Presentation of results .29
5.5.1 Standard thermal output of a model.29
5.5.2 Determination of the catalogue outputs of a type made at variable water
flow rate . 30
6 Test report .30
Annex A (normative) Master radiators dimensional verification .33
Annex B (informative) Determination of pressure drop .38
Annex C (normative) Least squares regression for a model .43
Annex D (normative) Analysis of test results by the method of least squares multiple
regression . 44
Annex E (normative) Specimen of the test report .46
Annex F (informative) Apparatus and method for checking the bulk temperature
measuring devices .49
Annex G (informative) Examples of typical appliances according to Table 4 .51
Annex H (normative) Determination of the Φ values of the master radiators primary set .61
M
Annex I (normative) Calculation method for determining the energy calculation parameters .62
iii
Bibliography .64
iv
Foreword
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v
Introduction
This document results from the recognition that the heating appliances falling into the field of
application hereinafter stated are traded on the basis of their thermal output.
To evaluate and compare different appliances it is therefore necessary to refer to a single stipulated
value, hereinafter called the standard rated thermal output.
In addition, for low temperature systems, a standard low temperature thermal output is given.
The standard thermal outputs (standard rated thermal output and standard low temperature thermal
output) are a defined value taken from the characteristic equation.
The pre-requisites of the standard thermal outputs, as defined by this document, are the following:
— to be representative of the actual output of the appliance in different operating conditions;
— to be reproducible within the tolerances defined by this document, taking into account the state of
measuring techniques;
— to be representative of the thermal outputs, obtainable under the same test conditions, of any
identical sample taken out of the current production (within the tolerances defined by this document,
taking into account the state of measuring techniques and methods of manufacture).
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INTERNATIONAL STANDARD ISO 24365:2022(E)
Radiators and convectors — Methods and rating for
determining the heat output
1 Scope
This document defines procedures for determining the standard thermal outputs and other
characteristics of radiators and convectors installed in a permanent manner in construction works, fed
with water or steam at temperatures below 120 °C, supplied by a remote energy source.
This document specifies the laboratory arrangements and testing methods to be adopted, the admissible
tolerances, the criteria for selecting the samples to be tested and for verifying the conformity of the
current production with the samples tested at the initial test.
This document also defines the additional common data that the manufacturer shall provide with the
product in order to ensure the correct application of the products.
This document does not apply to fan-assisted radiators, fan-assisted convectors and trench convectors
or to independent heating 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.
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
3 Terms, definitions, symbols and units
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions 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/
3.1.1
heating appliance
device having the purpose of transferring heat in order to provide specific temperature conditions
inside buildings
3.1.2
independent heating appliance
self-contained heat
...