EN 1751:2024

SLOVENSKI STANDARD
01-julij-2024
Nadomešča:
SIST EN 1751:2014
Prezračevanje stavb - Naprave za vtok in odtok zraka - Aerodinamično
preskušanje dušilnikov in loput
Ventilation for buildings - Air terminal devices - Aerodynamic testing of damper and
valves
Lüftung von Gebäuden - Geräte des Luftverteilungssystems - Aerodynamische
Prüfungen von Drossel- und Absperrelementen
Ventilation des bâtiments - Bouches d'air - Essais aérodynamiques des registres et
clapets
Ta slovenski standard je istoveten z: EN 1751:2024
ICS:
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 1751
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2024
EUROPÄISCHE NORM
ICS 91.140.30 Supersedes EN 1751:2014
English Version
Ventilation for buildings - Air terminal devices -
Aerodynamic testing of damper and valves
Ventilation des bâtiments - Bouches d'air - Essais Lüftung von Gebäuden - Geräte des
aérodynamiques des registres et clapets Luftverteilungssystems - Aerodynamische Prüfungen
von Drossel- und Absperrelementen
This European Standard was approved by CEN on 15 April 2024.

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

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

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1751:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms, definitions, symbols and suffixes . 5
3.1 Terms and definitions . 5
3.2 Symbols . 5
3.3 Suffixes . 6
4 Instrumentation . 6
4.1 Air flow rate measurement . 6
4.2 Pressure measurement. 7
4.3 Temperature measurement . 7
5 Leakage tests . 8
5.1 General. 8
5.2 Damper and valve leakage. 8
5.3 Casing leakage . 8
6 Flow rate and pressure tests. 9
6.1 Ducted method . 9
6.2 Chamber method . 10
6.2.1 General. 10
6.2.2 Size relationship . 10
6.2.3 Tests . 10
6.3 Calculations and report . 11
Annex A (informative) Mechanical testing of dampers and valves . 18
A.1 General. 18
A.2 Instrumentation: Torque measurement . 18
A.3 Pressure test to determine limiting value for structural stability . 18
A.4 Torque tests to determine the torque required to operate the damper or valve and
the limiting value to avoid structural damage . 19
Annex B (informative) Thermal transmittance through dampers and valves . 21
B.1 General. 21
B.2 Thermal loss test using a substitution method . 21
Annex C (normative) Classification of a damper or valve leakage . 24
C.1 General. 24
C.2 Leakage through closed blade(s) . 24
C.3 Casing leakage . 26
Annex D (informative) Effect of duct configuration on pressure loss coefficient . 28
D.1 General. 28
D.2 Application of correction factor . 29
Bibliography . 30
European foreword
This document (EN 1751:2024) has been prepared by Technical Committee CEN/TC 156 “Air terminal
devices”, the secretariat of which is held by BSI.
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 November 2024, and conflicting national standards shall
be withdrawn at the latest by November 2024.
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 1751:2014.
In comparison with the previous edition, EN 1751:2014, the following technical modifications have been
made:
— Annex C Classification of a damper or valve leakage;
• Closed blade leakage now has the addition of formulae for the calculation of classification levels
and an improved graph;
• Case leakage now has formulae for classification which are based on ductwork leakage classes
in EN 16798-3:2017, Table19 taking a reference case length of 1 m and also an improved graph.
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
This document specifies methods for the testing and rating of dampers and valves used in air distribution
systems with pressure differences up to 2 000 Pa.
The tests incorporated in this document will address:
— leakage past a closed damper or valve (for classification, see Annex C);
— casing leakage (for classification, see Annex C);
— flow rate/pressure requirement characteristics;
— torque: (see Annex A);
— thermal transmittance: (see Annex B).
The tests specified above are applicable to the following:
— measurement of leakage past a closed damper or valve;
— measurement of casing leakage;
— determination of flow rate and pressure requirements;
— measurement of torque characteristics (see Annex A);
— measurement of thermal transfer characteristics to determine insulation properties (see Annex B).
This document does not apply to the acoustic testing of dampers and valves.
NOTE Certain aspects of the dynamic performance of dampers and/or valves are dependent upon the air
distribution system to which they are connected and are, therefore, difficult to measure in isolation. Such
considerations have led to the omission of these aspects of the dynamic performance measurements from this
document. Also, in common with other air distribution components, the results from tests carried out in accordance
with this document might not be directly applicable if the damper or valve is situated in an area of non-uniform
flow.
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 12792, Ventilation for buildings — Symbols, terminology and graphical symbols
EN 16798-3:2017, Energy performance of buildings — Ventilation for buildings — Part 3: For non-
residential buildings — Performance requirements for ventilation and room-conditioning systems (Modules
M5-1, M5-4)
CEN/TS 17153, Ventilation for buildings — Correction of air flow rate according to ambient conditions
EN ISO 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full — Part 1: General principles and requirements (ISO 5167-1)
EN ISO 5167-2, Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full — Part 2: Orifice plates (ISO 5167-2)
EN ISO 5167-3, Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full — Part 3: Nozzles and Venturi nozzles (ISO 5167-3)
EN ISO 5167-4, Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full — Part 4: Venturi tubes (ISO 5167-4)
3 Terms, definitions, symbols and suffixes
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12792 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/
3.2 Symbols
The symbols used in this document are given in Table 1.
Table 1 — Symbols
Symbol Quantity Unit
A Internal cross-sectional area of duct m
C Coefficient of discharge -
D
D Equivalent diameter m
e
4 A
Circular ducts:
π
2ab
Square/Rectangular ducts:
ab+
p Absolute pressure Pa
p Atmospheric pressure Pa
a
p Velocity pressure 1/2 ρ v Pa
d
p Stagnation or absolute total pressure Pa
t
p Static gauge pressure (p - p ) Pa
s a
Δp Pressure difference across the damper or valve under test Pa
s
Δp Flow meter differential pressure Pa
Δp Conventional total pressure difference for an air density of Pa
t
−3
1,2 kg⋅m at the inlet to the damper or valve under test
−1
q Volume rate of air flow at the flow meter l⋅s
v
−1
q Leakage volume rate of air flow l⋅s
vL
−1 −2
q Closed blade air leakage factor, volume rate of air flow per unit l⋅s ⋅m
vLBA
duct cross
...