SIST EN 13141-7:2021
(Main)Ventilation for buildings - Performance testing of components/products for residential ventilation - Part 7: Performance testing of ducted mechanical supply and exhaust ventilation units (including heat recovery)
Ventilation for buildings - Performance testing of components/products for residential ventilation - Part 7: Performance testing of ducted mechanical supply and exhaust ventilation units (including heat recovery)
This document specifies the laboratory test methods and test requirements for the testing of aerodynamic, thermal, acoustic and electrical performance characteristics of ducted mechanical supply and exhaust ventilation units intended for single family houses.
This document is applicable to unit that contain at least, within one or more casing:
- fans for mechanical supply and exhaust;
- air filters;
- air-to-air heat exchanger and/or air-to-air heat pump for air heat recovery;
- control system.
Such unit can be provided in more than one assembly, the separate assemblies of which are designed to be used together.
The different possible arrangements of heat recovery, heat exchangers and/or heat pumps are described in Annex A.
This document does not deal with non-ducted units.
This document does not cover ventilation systems that may also provide water space heating and hot water.
This document does not cover units including combustion engine, driven compression heat pumps and absorption heat pumps.
Electrical safety requirements are given in EN 60335 2 40 and EN 60335 2 80.
Lüftung von Gebäuden - Leistungsprüfungen von Bauteilen/Produkten für die Lüftung von Wohnungen - Teil 7: Leistungsprüfung von mechanischen Zuluft‐ und Ablufteinheiten (einschließlich Wärmerückgewinnung)
Dieses Dokument legt die Laborprüfverfahren und die Anforderungen an die Prüfung der aerodynamischen, thermischen und akustischen sowie der elektrischen Leistungskenngrößen von mechanischen Zuluft- und Fortluftgeräten mit Kanalanschluss für Wohnungen fest.
ANMERKUNG Derartige Geräte werden in EN 13142:2021 als bidirektionale Lüftungsgeräte bezeichnet.
Dieses Dokument ist auf Geräte anwendbar, die in einem oder mehreren Gehäuse(n) mindestens Folgendes umfassen:
— Ventilatoren für mechanische Zuluft- und Fortlufteinheiten;
— Luftfilter;
— Luft-Luft-Wärmeübertrager und/oder Luft/Luft-Wärmepumpen für die Wärmerückgewinnung;
— Steuer und Regeleinrichtungen.
Ein derartiges Gerät kann in mehr als einer Baugruppe geliefert werden, wobei die einzelnen Bau-gruppen dafür ausgelegt sind, zusammen verwendet zu werden.
Beispiele für die verschiedenen möglichen Anordnungen von Wärmerückgewinnung, Wärmeübertrager und/oder Wärmepumpen sind in Anhang A beschrieben.
Dieses Dokument deckt Lüftungsgeräte mit kontinuierlichen Masseströmen für jeden Betriebspunkt ab.
Dieses Dokument behandelt keine Geräte ohne Kanalanschluss; diese werden in prEN 13141 8:2021 behandelt.
Dieses Dokument behandelt keine Lüftungsanlagen, die auch für die Warmwasser-Raumheizung und die Warmwasserbereitung eingesetzt werden dürfen; diese werden in EN 16573 behandelt.
Dieses Dokument behandelt keine Geräte, die Kompressionswärmepumpen mit Antrieb durch Ver-brennungsmotor und Absorptionswärmepumpen umfassen.
Die Anforderungen an die elektrische Sicherheit sind in EN 60335 2 40 und EN 60335 2 80 angegeben.
Ventilation des bâtiments - Essais de performance des composants/produits pour la ventilation des logements - Partie 7 : Essais de performance des centrales double flux (y compris la récupération de chaleur)
LLe présent document spécifie les méthodes d’essai de laboratoire et les exigences d’essai pour les essais des caractéristiques de performances aérauliques, thermiques, acoustiques et électriques des centrales double flux pour les logements.
NOTE Ces centrales sont appelées centrales de ventilation bidirectionnelles dans l’EN 13142:2021.
Le présent document est applicable aux centrales contenant au moins, dans une ou plusieurs enveloppes :
- des ventilateurs pour l’alimentation et l'extraction mécaniques ;
- des filtres à air ;
- un échangeur de chaleur air-air et/ou une pompe à chaleur air-air pour la récupération de chaleur de l’air ;
- un système de régulation.
Une telle centrale peut être fournie en plusieurs assemblages, ces assemblages individuels étant conçus pour être utilisés conjointement.
Des exemples de différentes configurations possibles de la récupération de chaleur, des échangeurs de chaleur et/ou des pompes à chaleur sont décrits à l’Annexe A.
Le présent document couvre les centrales de ventilation à débit massique continu pour chaque point de réglage.
Le présent document ne traite pas des unités décentralisées qui sont traitées dans le prEN 13141-8:2021.
Le présent document ne couvre pas les systèmes de ventilation qui peuvent également fournir de l'eau de chauffage et de l’eau chaude qui sont traités dans l'EN 16573.
Le présent document ne couvre pas les centrales comprenant des pompes à chaleur à compression entraînées par un moteur à combustion et des pompes à chaleur à absorption.
Les exigences de sécurité électrique sont données dans l’EN 60335-2-40 et l'EN 60335-2-80.
Prezračevanje stavb - Preskušanje lastnosti sestavnih delov/izdelkov za prezračevanje stanovanjskih stavb - 7. del: Preskušanje lastnosti mehanskih kanalnih dovodnih in odvodnih prezračevalnih enot (vključno z enotami za vračanje toplote)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 13141-7:2021
01-junij-2021
Nadomešča:
SIST EN 13141-7:2011
Prezračevanje stavb - Preskušanje lastnosti sestavnih delov/izdelkov za
prezračevanje stanovanjskih stavb - 7. del: Preskušanje lastnosti mehanskih
kanalnih dovodnih in odvodnih prezračevalnih enot (vključno z enotami za
vračanje toplote)
Ventilation for buildings - Performance testing of components/products for residential
ventilation - Part 7: Performance testing of ducted mechanical supply and exhaust
ventilation units (including heat recovery)
Lüftung von Gebäuden - Leistungsprüfungen von Bauteilen/Produkten für die Lüftung
von Wohnungen - Teil 7: Leistungsprüfung von mechanischen Zuluft‐ und
Ablufteinheiten (einschließlich Wärmerückgewinnung)
Ventilation des bâtiments - Essais de performance des composants/produits pour la
ventilation des logements - Partie 7 : Essais de performance des centrales double flux (y
compris la récupération de chaleur)
Ta slovenski standard je istoveten z: EN 13141-7:2021
ICS:
91.140.30 Prezračevalni in klimatski Ventilation and air-
sistemi conditioning systems
SIST EN 13141-7:2021 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN 13141-7:2021
---------------------- Page: 2 ----------------------
SIST EN 13141-7:2021
EN 13141-7
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2021
EUROPÄISCHE NORM
ICS 91.140.30 Supersedes EN 13141-7:2010
English Version
Ventilation for buildings - Performance testing of
components/products for residential ventilation - Part 7:
Performance testing of ducted mechanical supply and
exhaust ventilation units (including heat recovery)
Ventilation des bâtiments - Essais de performance des Lüftung von Gebäuden - Leistungsprüfungen von
composants/produits pour la ventilation des Bauteilen/Produkten für die Lüftung von Wohnungen -
logements - Partie 7 : Essais de performance des Teil 7: Leistungsprüfung von mechanischen Zuluft- und
centrales double flux (y compris la récupération de Ablufteinheiten (einschließlich Wärmerückgewinnung)
chaleur)
This European Standard was approved by CEN on 25 January 2021.
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, Turkey 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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13141-7:2021 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
Contents Page
European foreword . 4
Introduction . 6
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Symbols and abbreviations . 13
5 Categories of heat exchangers . 16
6 Requirements . 16
7 Test methods . 18
7.1 General . 18
7.2 Performance testing of aerodynamic characteristics . 18
7.2.1 Leakages . 18
7.2.2 Air flow/pressure curve . 20
7.2.3 Electrical power input . 25
7.2.4 Filter bypass . 25
7.3 Performance testing of thermal characteristics . 26
7.3.1 General . 26
7.3.2 Test operating conditions . 26
7.3.3 Temperature conditions . 27
7.3.4 Test procedure . 29
7.3.5 Evaluation on supply air side (mandatory measurement) . 30
7.3.6 Evaluation on exhaust air side (optional measurement) . 31
7.3.7 Heat pump performance . 31
7.3.8 Combined heat pump and air-to-air heat exchanger performance . 32
7.4 Performance testing of acoustic characteristics . 32
7.4.1 General . 32
7.4.2 Noise radiated through the casing of the unit . 32
7.4.3 Sound power level in duct connections of the unit . 34
8 Test results . 37
8.1 Test report . 37
8.2 Product specifications . 37
8.3 Leakages . 37
8.4 Air flow/pressure curve . 38
8.5 Heat pump exhaust air/outdoor air performances . 38
8.6 Temperature ratios . 38
8.7 Acoustic characteristics . 39
8.8 Electrical power input . 39
Annex A (informative) Example of some possible arrangements of heat recovery heat
exchanger and/or heat pumps for category I . 40
Annex B (normative) Pressure leakage test method . 42
B.1 External leakage . 42
B.2 Internal leakage test . 42
2
---------------------- Page: 4 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
Annex C (normative) Tracer gas test method . 44
C.1 General method for rating purposes . 44
C.2 Augmented method for measuring instantaneous recirculation of ducted units
under different operating conditions (optional) . 45
C.3 Testing orders for tracer gas tests . 46
Annex D (normative) Evaluation of maximum air volume flow and pressure . 49
Annex E (normative) Evaluation of reference pressure . 51
Annex F (normative) Connection boxes . 52
Bibliography . 54
3
---------------------- Page: 5 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
European foreword
This document (EN 13141-7:2021) has been prepared by Technical Committee CEN/TC 156 “Ventilation
for buildings”, 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 October 2021, and conflicting national standards shall
be withdrawn at the latest by October 2021.
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 13141-7:2010.
In addition to a number of editorial revisions, the following main changes have been made with respect
to EN 13141-7:2010:
— terms and definitions as well as the symbols and abbreviations have been updated in accordance
with the parameters used in the document;
— new categories of heat exchanger have been added;
— general requirements of the static pressure distribution have been added in 7.1;
— the reference of the internal and external leakage rates has been changed to the reference air volume
flow;
— requirements to convert the measured values to standard conditions have been added in 7.2.2.1 and
7.3.2;
— determination of the external static pressure difference, maximum air flow and reference air flow
has been added;
— 7.3.3 has been divided into two separate subclauses, 7.3.3.1 for standard tests and 7.3.3.2 for cold
climate tests;
— the formulas to calculate the temperature ratios have been changed;
— the wet bulb temperature for the cold climate test has been changed;
— Annex D, giving examples for the evaluation of maximum air volume flow and pressure, has been
added;
— Annex E giving examples for the evaluation of reference pressure has been added;
— the description of the connection box has been moved to Annex F.
A list of all parts in the EN 13141 series, published under the general title Ventilation for buildings —
Performance testing of components/products for residential ventilation can be found on the CEN website.
4
---------------------- Page: 6 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
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, Turkey and the United
Kingdom.
5
---------------------- Page: 7 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
Introduction
This document specifies methods for the performance testing of components used in residential
ventilation systems to establish the performance characteristics as identified in EN 13142:2021.
This document does not contain any information on ductwork and fittings, which are covered by other
European Standards.
This document can be used for the following applications:
— laboratory testing;
— attestation purposes.
The position of this document in the field of standards for the mechanical building services is shown in
Figure 1.
6
---------------------- Page: 8 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
Mechanical Building Services
Control systems Ventilation and air conditioning systems Heating systems
Air terminal Air handling Mechanical and natural Design criteria for the System
Ductwork Installation
devices units residential ventilation indoor environment performance
Components/products for
Performance testing and
residential ventilation Performance testing of Simplified calculation Design and dimensioning for
installation checks for
Required and optional components/products for methods for residential residential ventilation
residential ventilation
performance residential ventilation ventilation systems systems
systems
characteristics
Part 1: Externally and internally mounted air transfer devices
Part 2: Exhaust and supply air terminal devices
Part 3: Range hoods for residential use without fan
Part 4: Aerodynamic, electrical power and acoustic performance of unidirectional
ventilation units
Part 5: Cowls, assisted cowls and roof outlet terminal devices
Part 6: Exhaust ventilation system packages used in a single dwelling
Part 7: Performance testing of ducted mechanical supply and exhaust ventilation units
(including heat recovery)
Part 8: Performance testing of non-ducted mechanical supply and exhaust ventilation
units (including heat recovery)
Part 9: Externally mounted humidity controlled air transfer device
Part 10: Humidity controlled extract air terminal device
Part 11: Supply ventilation units
Figure 1 — Position of EN 13141-7 in the field of the mechanical building services
7
---------------------- Page: 9 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
1 Scope
This document specifies the laboratory test methods and test requirements for the testing of
aerodynamic, thermal, acoustic and electrical performance characteristics of ducted mechanical supply
and exhaust residential ventilation units.
NOTE Such units are referred to as bidirectional ventilation units in EN 13142:2021.
This document is applicable to unit that contain at least, within one or more casing:
— fans for mechanical supply and exhaust;
— air filters;
— air-to-air heat exchanger and/or air-to-air heat pump for air heat recovery;
— control system.
Such unit can be provided in more than one assembly, the separate assemblies of which are designed to
be used together.
Examples of different possible arrangements of heat recovery, heat exchangers and/or heat pumps are
described in Annex A.
This document covers ventilation units with continuous mass flows for each setting point.
This document does not deal with non-ducted units that are treated in prEN 13141-8:2021.
This document does not cover ventilation systems that may also provide water space heating and hot
water that are treated in EN 16573.
This document does not cover units including combustion engine driven compression heat pumps and
absorption heat pumps.
Electrical safety requirements are given in EN 60335-2-40 and EN 60335-2-80.
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 14511 (all parts), Air conditioners, liquid chilling packages and heat pumps with electrically driven
compressors for space heating and cooling and process chillers, with electrically driven compressors
EN 14511-3, 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 14511-4, Air conditioners, liquid chilling packages and heat pumps for space heating and cooling and
process chillers, with electrically driven compressors — Part 4: Requirements
EN ISO 5135, Acoustics — Determination of sound power levels of noise from air-terminal devices, air-
terminal units, dampers and valves by measurement in a reverberation test room (ISO 5135)
EN ISO 5136, Acoustics — Determination of sound power radiated into a duct by fans and other air-moving
devices — In-duct method (ISO 5136)
8
---------------------- Page: 10 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
EN ISO 5801, Fans — Performance testing using standardized airways (ISO 5801)
EN ISO 16890 (all parts), Air filters for general ventilation (ISO 16890 (all parts))
ISO 13347-2, Industrial fans — Determination of fan sound power levels under standardized laboratory
conditions — Part 2: Reverberant room method
ISO 13347-3, Industrial fans — Determination of fan sound power levels under standardized laboratory
conditions — Part 3: Enveloping surface methods
ISO 13347-4, Industrial fans — Determination of fan sound power levels under standardized laboratory
conditions — Part 4: Sound intensity method
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12792 and the following apply.
ISO and IEC maintain terminological databases for the use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
external leakage
q
ve
leakage to or from the air flowing inside the casing of the ventilation unit to or from the surrounding air
[SOURCE: EN 13141-4:2021, 3.11]
3.2
internal leakage
q
vi
leakage inside the unit between the exhaust and the supply air flows
3.3
transfer ratio
R
s
mass transfer of the discharged air to a zone that is actually recirculated air from the same zone, due to
internal leakage and external casing leakage
Note 1 to entry: If the transfer ratio is determined with the induct method then it is called R and if it is
s,int
determined with the chamber method then it is called R .
s,tot
Note 2 to entry: In Figure 2 that represents a test installation for single inlet/outlet unit, the mass transfer of the
discharged air to a zone goes from key 4 (extract air) to key 5 (supply air).
3.4
filter bypass leakage
air bypass around filter cells
9
---------------------- Page: 11 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
3.5
maximum air volume flow at zero pressure
q
vmax,0
measured air volume flow corresponding to the maximum achievable fan curve setting of the unit, at 0 Pa
unit static pressure, p
us
[SOURCE: EN 13141-4:2021, 3.4]
3.6
declared maximum air volume flow
q
vmax,d
declared maximum air volume flow of the unit
[SOURCE: EN 13141-4:2021, 3.6]
3.7
maximum air volume flow
q
vmax
air volume flow corresponding to the maximum achievable fan curve setting of the unit at the pressure
p , either declared or measured
qvmax
Note 1 to entry: To determine maximum air volume flow, see 7.2.2.2, Table 9.
Note 2 to entry: If the supply and exhaust air volume flows are different, then the maximum air volume flow is
equal to the smaller of the two air volume flows.
[SOURCE: EN 13141-4:2021, 3.7, modified – Note 2 to entry has been added]
3.8
declared minimum air volume flow
q
vmin,d
minimum air volume flow of the unit declared at the reference pressure declared
Note 1 to entry: If the supply and exhaust air volume flows are different, then the minimum air volume flow is
equal to the higher of the two air volume flows.
3.9
reference air volume flow
q
vref
air volume flow corresponding to the reference pressure
Note 1 to entry: To determine reference air volume flow, see 7.2.2.3, Table 10.
[SOURCE: EN 13141-4:2021, 3.8]
10
---------------------- Page: 12 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
3.10
unit pressure
p
u
pressure increase induced by the ventilation unit given as difference between the total pressures at the
unit outlet and the unit inlet
Note 1 to entry: In case of equal cross-section areas of the inlet and outlet, the total pressure difference is equal
to the external static pressure difference.
Note 2 to entry: The parameter p for a ventilation unit is defined as the parameter p described in EN ISO 5801
u f
for a stand alone fan.
[SOURCE: EN 13141-4:2021, 3.1]
3.11
unit static pressure
p
us
pressure increase induced by the ventilation unit given as difference between the static pressure at the
unit outlet and the total pressure at the unit inlet
Note 1 to entry: The parameter p for a ventilation unit is defined as the parameter p described in EN ISO 5801
us fs
for a stand alone fan.
[SOURCE: EN 13141-4:2021, 3.2]
3.12
external static pressure difference
p
s,ext
pressure increase induced by the ventilation unit given as difference between the static pressures at the
unit outlet and the unit inlet
Note 1 to entry: The external static pressure difference is used to determine the maximum air volume flow, the
reference air volume flow and the minimum air volume flow.
[SOURCE: EN 13141-4:2021, 3.3, modified – “and the minimum air volume flow” has been added in
Note 1]
3.13
pressure at maximum air volume flow
p
qvmax
external static pressure difference, p , corresponding to the maximum air volume flow
s,ext
[SOURCE: EN 13141-4:2021, 3.5]
3.14
reference pressure
p
ref
external static pressure difference, p , corresponding to the reference air volume flow
s,ext
[SOURCE: EN 13141-4:2021, 3.9]
11
---------------------- Page: 13 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
3.15
temperature ratio
η
θ
temperature difference between inlet and outlet of one of the air flows divided by the temperature
difference between the inlets of both air flows
3.16
humidity ratio
η
x
difference of vapour mixing ratio between inlet and outlet of one of the air flows divided by the difference
of vapour mixing ratio between the inlets of both air flows
3.17
electrical power input
P
E
average overall electrical power input to the equipment within a defined interval of time for standard air
conditions obtained from:
— the power input of the fans;
— controller(s), compressor(s), safety devices of the equipment(s) excluding additional electrical
heating devices not used for defrosting
Note 1 to entry: Electrical power consumption includes the consumption of the heating device for defrosting
during the cold climate test.
[SOURCE: EN 13141-4:2021, 3.15, modified – Note 1 to entry has been added]
3.18
maximum electrical power input
P
E,max
electrical power input at maximum air volume flow, q , and its corresponding pressure, p
vmax qvmax
[SOURCE: EN 13141-4:2021, 3.17]
3.19
electrical power input at the reference air volume flow
P
E,ref
electrical power input at reference air volume flow, q , and reference pressure, p
vref ref
[SOURCE: EN 13141-4:2021, 3.16]
3.20
ventilation unit
casing incorporating at least a fan, and that may include duct connections, filters, coils, electrical heating,
or any other air treatment component
[SOURCE: EN 13141-4:2021, 3.10]
12
---------------------- Page: 14 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
4 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in EN 12792 and in Table 1
apply.
Table 1 — Symbols
Symbol Designation Unit
c concentration of tracer gas ppm
D diameter of the measurement duct (see Figure 3) m
D hydraulic diameter of the connecting duct (see Figure 3) m
h2
D instantaneous deviation from net transfer ratio —
i
L instantaneous apparent net transfer ratio —
i
L sound power level dB
W
L A-weighted sound power level dB
WA
global sound power level dB
L
w,global
sound power level of a single duct connection dB
L
w,single
m mass kg
N number of identical duct connections —
P
electrical power input W
E
P
maximum electrical power input W
E,max
P
electrical power input at the reference air volume flow W
E,ref
P electrical power input under test conditions measured at the W
E,Te
density of the ambient air at the test enclosure, ρ
Te
p pressure Pa
p pressure at maximum air volume flow Pa
qvmax
p reference pressure Pa
ref
p external static pressure difference Pa
s,ext
p
to be set external static pressure difference Pa
s,ext,set
p
unit static pressure difference under test conditions measured at Pa
s,ext,T
e
the density ρ
Te
p unit pressure Pa
u
p unit static pressure Pa
us
unit static pressure under test conditions measured at the density Pa
p
us,T
e
ρ
Te
p static pressure at inlet side Pa
3
13
---------------------- Page: 15 ----------------------
SIST EN 13141-7:2021
EN 13141-7:2021 (E)
Symbol Designation Unit
p usable static pressure at outlet side Pa
4
-1 b
q mass flow rate
kg.s
m
-1 b
dry mass flow rate
q kg.s
m
dry
-1 b
moisture mass flow rate
q kg.s
m
moist
-1 b
q
to be set mass flow
kg.s
m,set
3 -1 a
q air volume flow
m .s
v
3 -1 a
q external leakage air volume flow rate
m .s
ve
3 -1 a
q to be set air volume flow
m .s
ve,set
3 -1 a
q internal leakage air volume flow
m .s
vi
3 -1 a
q maximum air volume flow
m .s
vmax
3 -1 a
q declared maximum air volume flow
m .s
vmax,d
3 -1 a
q maximum air volume flow at zero pressure
m .s
vmax,0
3 -1 a
q declared minimum air volume flow
m .s
vmin,d
3 -1 a
q reference air volume flow
m .s
vref
R %
transfer ratio of recirculated air in the exhaust air stream
e
R instantaneous estimated true transfer ratio of recirculated air in %
e,i
the exhaust air stream (ducted units)
R maximum transfer ratio of recirculated air in the exhaust air %
e,max
stream
R
%
transfer ratio of recirculated air in the supply air stream
s
R
instantaneous estimated true transfer ratio of recirculated air in %
s,i
the supply air stream (ducted units)
R %
internal transfer ratio from extract to supply air
s,
...
SLOVENSKI STANDARD
oSIST prEN 13141-7:2018
01-oktober-2018
3UH]UDþHYDQMHVWDYE3UHVNXãDQMHODVWQRVWLVHVWDYQLKGHORYL]GHONRY]D
SUH]UDþHYDQMHVWDQRYDQMVNLKVWDYEGHO3UHVNXãDQMHODVWQRVWLPHKDQVNLK
NDQDOQLKGRYRGQLKLQRGYRGQLKHQRWYNOMXþQR]HQRWDPL]DYUDþDQMHWRSORWH
Ventilation for buildings - Performance testing of components/products for residential
ventilation - Part 7: Performance testing of ducted mechanical supply and exhaust
ventilation units (including heat recovery)
/IWXQJYRQ*HElXGHQ/HLVWXQJVSUIXQJHQYRQ%DXWHLOHQ3URGXNWHQIUGLH/IWXQJ
YRQ:RKQXQJHQ7HLO/HLVWXQJVSUIXQJYRQPHFKDQLVFKHQ=XOXIW"XQG
$EOXIWHLQKHLWHQHLQVFKOLH‰OLFK:lUPHUFNJHZLQQXQJ
Ventilation des bâtiments - Essais de performance des composants/produits pour la
ventilation des logements - Partie 7 : Essais de performance des centrales double flux (y
compris la récupération de chaleur)
Ta slovenski standard je istoveten z: prEN 13141-7
ICS:
91.140.30 3UH]UDþHYDOQLLQNOLPDWVNL Ventilation and air-
VLVWHPL conditioning systems
oSIST prEN 13141-7:2018 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST prEN 13141-7:2018
---------------------- Page: 2 ----------------------
oSIST prEN 13141-7:2018
DRAFT
EUROPEAN STANDARD
prEN 13141-7
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2018
ICS 91.140.30 Will supersede EN 13141-7:2010
English Version
Ventilation for buildings - Performance testing of
components/products for residential ventilation - Part 7:
Performance testing of ducted mechanical supply and
exhaust ventilation units (including heat recovery)
Ventilation des bâtiments - Essais de performance des Lüftung von Gebäuden - Leistungsprüfungen von
composants/produits pour la ventilation des Bauteilen/Produkten für die Lüftung von Wohnungen -
logements - Partie 7 : Essais de performance des Teil 7: Leistungsprüfung von mechanischen Zuluft- und
centrales double flux (y compris la récupération de Ablufteinheiten (einschließlich Wärmerückgewinnung)
chaleur)
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 156.
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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 13141-7:2018 E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Symbols and abbreviations . 11
5 Categories of heat exchangers . 12
6 Requirements . 13
7 Test methods . 14
7.1 General . 14
7.2 Performance testing of aerodynamic characteristics . 14
7.2.1 Leakages . 14
7.2.2 Air flow/pressure curve . 16
7.2.3 Electrical power input . 20
7.2.4 Filter bypass . 20
7.3 Performance testing of thermal characteristics . 21
7.3.1 General . 21
7.3.2 Test operating conditions . 21
7.3.3 Temperature conditions . 21
7.3.4 Test procedure . 22
7.3.5 Evaluation on supply air side (mandatory measurement) . 23
7.3.6 Evaluation on exhaust air side (optional measurement) . 24
7.3.7 Heat pump performance . 24
7.3.8 Combined heat pump and air-to-air heat exchanger performance . 25
7.4 Performance testing of acoustic characteristics . 25
7.4.1 Noise radiated through the casing of the unit . 25
7.4.2 Sound power level in duct connections of the unit . 26
8 Test results . 28
8.1 Test report . 28
8.2 Product specifications . 29
8.3 Leakages . 29
8.4 Air flow/pressure curve . 30
8.5 Heat pump exhaust air/outdoor air performances . 30
8.6 Temperature ratios . 30
8.7 Acoustic characteristics . 31
8.8 Electrical power input . 31
Annex A (informative) Example of some possible arrangements of heat recovery heat
exchanger and/or heat pumps for category I . 32
Annex B (normative) Pressure leakage test method . 34
B.1 External leakage . 34
B.2 Internal leakage test . 34
2
---------------------- Page: 4 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
Annex C (normative) Tracer gas test method . 36
C.1 General method for rating purposes . 36
C.2 Augmented method for measuring instantaneous recirculation of ducted units
under different operating conditions (optional) . 37
C.3 Testing orders for tracer gas tests . 38
Annex D (normative) Examples for the evaluation of maximum air volume flow and
pressure . 42
Annex E (normative) Examples for the evaluation of reference pressure . 43
Annex F (normative) Connection boxes . 44
Bibliography . 46
3
---------------------- Page: 5 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
European foreword
This document (prEN 13141-7:2018) has been prepared by Technical Committee CEN/TC 156
“Ventilation for buildings”, the secretariat of which is held by BSI.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 13141-7:2010.
In addition to a number of editorial revisions, the following main changes have been made with respect
to EN 13141-7:2010:
— terms and definitions as well as the symbols and abbreviations have been updated in accordance
with the parameters used in the document;
— new categories of heat exchanger have been added;
— general requirements of the static pressure distribution have been added in 7.1;
— the reference of the internal and external leakage rates has been changed to the reference air
volume flow;
— requirements to convert the measured values to standard conditions have been added in 7.2.2.1;
— determination of the static pressure difference, maximum air flow and reference air flow has been
added;
— the formulas to calculate the temperature ratios have been changed;
— the wet bulb temperature for the cold climate test has been changed;
— Annex D, giving examples for the evaluation of maximum air volume flow and pressure, has been
added;
— Annex E giving examples for the evaluation of reference pressure has been added;
— the description of the connection box has been moved to Annex F.
A list of all parts in the EN 13141 series, published under the general title Ventilation for buildings —
Performance testing of components/products for residential ventilation can be found on the CEN website.
4
---------------------- Page: 6 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
Introduction
This document specifies methods for the performance testing of components used in residential
ventilation systems to establish the performance characteristics as identified in prEN 13142.
This document does not contain any information on ductwork and fittings, which are covered by other
European Standards.
This document can be used for the following applications:
— laboratory testing;
— attestation purposes.
The position of this document in the field of standards for the mechanical building services is
shown in Figure 1.
5
---------------------- Page: 7 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
Figure 1 — Position of EN 13141-7 in the field of the mechanical building services
6
---------------------- Page: 8 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
1 Scope
This document specifies the laboratory test methods and test requirements for the testing of
aerodynamic, thermal, acoustic and electrical performance characteristics of ducted mechanical supply
and exhaust ventilation units intended for single family houses.
This document is applicable to unit that contain at least, within one or more casing:
— fans for mechanical supply and exhaust;
— air filters;
— air-to-air heat exchanger and/or air-to-air heat pump for air heat recovery;
— control system.
Such unit can be provided in more than one assembly, the separate assemblies of which are designed to
be used together.
The different possible arrangements of heat recovery, heat exchangers and/or heat pumps are
described in Annex A.
This document does not deal with non-ducted units.
This document does not cover ventilation systems that may also provide water space heating and hot
water.
This document does not cover units including combustion engine, driven compression heat pumps and
absorption heat pumps.
Electrical safety requirements are given in EN 60335-2-40 and EN 60335-2-80.
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 306, Heat exchangers - Methods of measuring the parameters necessary for establishing the
performance
EN 12792, Ventilation for buildings - Symbols, terminology and graphical symbols
EN 14511 (all parts), Air conditioners, liquid chilling packages and heat pumps with electrically driven
compressors for space heating and cooling
EN 14511-3, 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 14511-4, Air conditioners, liquid chilling packages and heat pumps for space heating and cooling and
process chillers, with electrically driven compressors - Part 4: Requirements
EN ISO 3741, Acoustics - Determination of sound power levels and sound energy levels of noise sources
using sound pressure - Precision methods for reverberation test rooms (ISO 3741)
EN ISO 3743-1, Acoustics - Determination of sound power levels and sound energy levels of noise sources
using sound pressure - Engineering methods for small movable sources in reverberant fields - Part 1:
Comparison method for a hard-walled test room (ISO 3743-1)
7
---------------------- Page: 9 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
EN ISO 3743-2, Acoustics - Determination of sound power levels of noise sources using sound pressure -
Engineering methods for small, movable sources in reverberant fields - Part 2: Methods for special
reverberation test rooms (ISO 3743-2)
EN ISO 3744, Acoustics - Determination of sound power levels and sound energy levels of noise sources
using sound pressure - Engineering methods for an essentially free field over a reflecting plane (ISO 3744)
EN ISO 3745, Acoustics - Determination of sound power levels and sound energy levels of noise sources
using sound pressure - Precision methods for anechoic rooms and hemi-anechoic rooms (ISO 3745)
EN ISO 5135, Acoustics - Determination of sound power levels of noise from air-terminal devices, air-
terminal units, dampers and valves by measurement in a reverberation room (ISO 5135)
EN ISO 5136, Acoustics - Determination of sound power radiated into a duct by fans and other air-moving
devices - In-duct method (ISO 5136)
EN ISO 5801, Fans - Performance testing using standardized airways (ISO 5801)
EN ISO 9614-1, Acoustics - Determination of sound power levels of noise sources using sound intensity -
Part 1: Measurement at discrete points (ISO 9614-1)
EN ISO 9614-2, Acoustics - Determination of sound power levels of noise sources using sound intensity -
Part 2: Measurement by scanning (ISO 9614-2)
EN ISO 9614-3, Acoustics - Determination of sound power levels of noise sources using sound intensity -
Part 3: Precision method for measurement by scanning (ISO 9614-3)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN ISO 5801 and EN 12792 and
the following apply.
ISO and IEC maintain terminological databases for the use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO online browsing platform: available at http://www.iso.org/obp
3.1
external leakage
qve
leakage to or from the air flowing inside the casing of the unit to or from the surrounding air
3.2
internal leakage
q
vi
leakage inside the unit between the exhaust and the supply air flows
3.3
transfer ratio
R
s
mass transfer of the discharged air to a zone (in Figure 2: from key 4 (extract) to key 5 (supply)) that is
actually recirculated air from the same zone, due to internal leakage and external casing leakage
8
---------------------- Page: 10 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
3.4
filter bypass leakage
air bypass around filter cells
3.5
maximum air volume flow at zero pressure
q
vmax,0
measured air volume flow corresponding to the maximum achievable fan curve setting of the unit, at
minimum static pressure difference p , which corresponds to 0 Pa static fan pressure p
s,ext fs
3.6
declared maximum air volume flow
q
vmax,d
maximum air volume flow of the unit declared by the manufacturer
3.7
maximum air volume flow
q
vmax
air volume flow corresponding to the maximum achievable fan curve setting of the unit at the pressure
p , either declared or measured
qvmax
Note 1 to entry: If the supply and exhaust air volume flows are different, then the maximum air volume flow is
equal to the smaller of the two air volume flows.
3.8
declared minimum air volume flow
q
vmin,d
minimum air volume flow of the unit at the reference pressure declared by the manufacturer
Note 1 to entry: If the supply and exhaust air volume flows are different, then the minimum air volume flow is
equal to the higher of the two air volume flows.
3.9
reference air volume flow
q
vref
air volume flow corresponding to the reference pressure
Note 1 to entry: To determine reference air volume flow, see 7.2.2.3, Table 10.
3.10
fan pressure
p
f
pressure increase induced by the ventilation unit given as difference between the total pressures at the
unit outlet and the unit inlet
[SOURCE: EN ISO 5801:2008, 3.38]
Note 1 to entry: In case of similar cross-section areas of the inlet and outlet, the total pressure difference is
equal to the static pressure difference.
9
---------------------- Page: 11 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
3.11
static fan pressure
p
fs
pressure increase induced by the ventilation unit given as difference between the static pressure at the
unit outlet and the total pressure at the unit inlet
[SOURCE: EN ISO 5801:2008, 3.40]
3.12
static pressure difference
p
s,ext
pressure increase induced by the ventilation unit given as difference between the static pressures at the
unit outlet and the unit inlet
Note 1 to entry: Static pressure difference is used to determine the maximum air volume flow, the reference air
volume flow and the minimum air volume flow.
3.13
pressure at maximum air volume flow
p
qvmax
static pressure difference corresponding to the maximum air volume flow
3.14
reference pressure
p
ref
static pressure difference corresponding to the reference air volume flow
3.15
temperature ratio
η
θ
temperature difference between inlet and outlet of one of the air flows divided by the temperature
difference between the inlets of both air flows
3.16
humidity ratio
η
x
difference of water content between inlet and outlet of one of the air flows divided by the difference of
water content between the inlets of both air flows
3.17
electrical power input
P
E
average over all electrical power input to the equipment within a defined interval of time for standard
air conditions obtained from the power input of the fans; controller(s), compressor(s), safety devices of
the equipment(s) excluding additional electrical heating devices not used for defrosting
Note 1 to entry: P is expressed in watts.
E
3.18
maximum electrical power input
PE,max
electrical power input at maximum air volume flow q and its corresponding pressure p
vmax qvmax
10
---------------------- Page: 12 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
3.19
electrical power input at the reference volume flow
P
E,ref
electrical power input at reference air volume flow q and reference pressure p
vref ref
4 Symbols and abbreviations
For the purposes of this document, the symbols and abbreviations given in EN 12792 and in Table 1
apply.
Table 1 — Symbols
Symbol Designation Unit
c concentration of tracer gas ppm
D diameter of the measurement duct (see Figure 3) m
D , D Hydraulic diameters of the connecting duct (see Figure 3) m
h1 h2
L sound power level dB
W
L A-weighted sound power level dB
WA
P electrical power input W
E
P electrical power input at the reference volume W
E,ref
P maximum electrical power input W
E,max
pE static pressure difference Pa
p fan pressure Pa
f
p static fan pressure Pa
fs
p pressure at maximum air volume flow Pa
qvmax
p reference pressure Pa
ref
p static pressure difference Pa
s,ext
-1 -1 -1
q mass air flow rate kg.s or kg h or g.s
m
3 -1 3 -1 -1
q air volume flow m .s or m h or l.s
v
3 -1 3 -1 -1
q maximum air volume flow m .s or m h or l.s
vmax
3 -1 3 -1 -1
q declared maximum air volume flow m .s or m h or l.s
vmax,d
3 -1 3 -1 -1
q maximum air volume flow at 0 pressure m .s or m h or l.s
vmax,0
3 -1 3 -1 -1
q reference air volume flow m .s or m h or l.s
vref
3 -1 3 -1 -1
q declared maximum air volume flow rate m .s or m h or l.s
vd
3 -1 3 -1 -1
q external leakage air volume flow rate m .s or m h or l.s
ve
3 -1 3 -1 -1
q internal leakage air volume flow rate m .s or m h or l.s
vi
R transfer ratio %
R transfer ratio —
s
-1
v air velocity in the measurement duct (see Figure 3) m.s
θ air temperature °C
11
---------------------- Page: 13 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
Symbol Designation Unit
θ wet bulb temperature °C
w
x water content kg water/kg dry air
21 outdoor air (ODA) (see Figure 2) —
22 supply air (SUP)(see Figure 2) —
11 extract air (ETA) (see Figure 2) —
12 exhaust air (EHA) (see Figure 2) —
ηθ, ex temperature ratio of the unit on exhaust air side —
η temperature ratio of the unit on supply air side —
θ, su
η humidity ratio of the unit on exhaust air side —
x, ex
η humidity ratio of the unit on supply air side —
x, su
3
ρ density of the air kg/m
5 Categories of heat exchangers
Categories of heat exchangers are given in Table 2.
Table 2 — Categories of heat exchangers
Category Definition
I Recuperative heat exchangers (e.g. air-to-air plate or tube heat exchanger)
Ia Recuperative heat exchangers of the category Ia are designed to transfer sensible
thermal energy from one air stream to another without moving parts. Heat transfer
surfaces are in form of plates or tubes. This heat exchanger can have parallel flow,
cross flow or counter flow construction or a combination of these.
Ib
Recuperative heat exchangers of the category Ib are designed to transfer total
thermal energy including vapour diffusion from one air stream to another without
moving parts. Heat transfer surfaces are in form of plates or tubes. This heat
exchanger can have parallel flow, cross flow or counter flow construction or a
combination of these.
b a
II Regenerative heat exchangers (e.g. rotary heat exchanger ).
a
A rotary heat exchanger is a device incorporating a rotating wheel for the purpose of transferring
thermal energy (sensible or total) from one air stream to the other. It incorporates material allowing
latent heat transfer, a drive mechanism, a casing or frame, and includes any seals which are provided to
retard bypassing and leakage or air from one air stream to the other.
b
Regenerative heat exchangers have varying degrees of moisture recovery, depending on the material
used (e.g. "condensation rotor/non hygroscopic rotor", "hygroscopic rotor" and 'sorption rotor" heat
exchangers).
12
---------------------- Page: 14 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
6 Requirements
In addition, to assess correctly the thermal performance, aerodynamic characteristics, including all
leakages, shall be tested before or together with any thermal characteristics testing (see 7.3).
Aerodynamic characteristics (see 7.2) shall include three characteristics listed below:
— external leakage or/and total transfer ratio in supply air;
— internal leakage or transfer ratio (R ) from extract to supply air or total transfer ratio (R ) in supply
s s
air;
— air flow/pressure curve.
Other characteristics such as filter bypass leakage are optional.
The tests for thermal performances shall not be made because of measurement uncertainty when
leakages according to 7.2.1 are too high. The unit shall have the leakage class specified in Table 3.
Table 3 — Classification requirements for thermal performance
Fan position required leakage class to
allow measurements
Exhaust fan upstream and supply fan downstream of the heat A1, B1
a
exchanger
Supply fan upstream and exhaust fan downstream of the heat A1, A2, B1, B2
exchanger
Other fan positions A1, A2, A3, B1, B2, B3
a
This configuration is not recommended for good indoor air quality.
The manufacturer shall declare:
— mandatory points:
— maximum air volume flow;
— minimum air volume flow;
— minimum outdoor operation temperature;
— filter classes supply and exhaust air;
— possibility of balancing the air volume flows;
— presence, type of by-pass and its control;
— frost protection function(s) and control (for cold climate test);
— category of heat exchanger;
13
---------------------- Page: 15 ----------------------
oSIST prEN 13141-7:2018
prEN 13141-7:2018 (E)
— adjustment of the purge sector and or the pressure settings on the wheel over the entire
operating range;
— nominal revolutions of the wheel;
— informal points:
— control parameter and sensors;
— type of fan and speed control;
— indented use;
— possible mounting positions.
7 Test methods
7.1 General
Tests shall be conducted with a unit containing all components as supplied for intended use, and
installed according to the manufacturer's instructions.
The mass flows q and q shall be measured in steady-state conditions at the same time.
m11 m22
The pressure difference shall be distributed 1/3 on the exhaust and outdoor side, and 2/3 on the supply
and extract side.
If internal and external leakage class A2 or better is reached, it can be assumed that q = q and
m11 m12
q = q and the pressure distribution between the inlet and outlet has no effect on the aerodynamic
m21 m22
measurements and the pressure distribution shall not be regarded.
Where a single value is assigned by the manufacturer as rated voltage, this shall be the test voltage.
Where a voltage range is assigned to the product by the
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.