SIST EN ISO 5802:2009

SLOVENSKI STANDARD
01-april-2009
Industrijski ventilatorji - Preskušanje lastnosti na mestu (ISO 5802:2001)
Industrial fans - Performance testing in situ (ISO 5802:2001)
Ventilateurs industriels - Essai de performance in situ (ISO 5802:2001)
Ta slovenski standard je istoveten z: EN ISO 5802:2008
ICS:
23.120 =UDþQLNL9HWUQLNL.OLPDWVNH Ventilators. Fans. Air-
QDSUDYH conditioners
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 5802
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2008
ICS 23.120
English Version
Industrial fans - Performance testing in situ (ISO 5802:2001)
Ventilateurs industriels - Essai de performance in situ (ISO
5802:2001)
This European Standard was approved by CEN on 2 October 2008.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5802:2008: E
worldwide for CEN national Members.

Contents Page
Foreword.3

Foreword
The text of ISO 5802:2001 has been prepared by Technical Committee ISO/TC 117 “Industrial fans” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 5802:2008 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 April 2009, and conflicting national standards shall be withdrawn at the
latest by April 2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 5802:2001 has been approved by CEN as a EN ISO 5802:2008 without any modification.

INTERNATIONAL ISO
STANDARD 5802
First edition
2001-07-15
Industrial fans — Performance testing
in situ
Ventilateurs industriels — Essai de fonctionnement in situ
Reference number
ISO 5802:2001(E)
©
ISO 2001
ISO 5802:2001(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not
be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this
file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this
area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters
were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event
that a problem relating to it is found, please inform the Central Secretariat at the address given below.
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body
in the country of the requester.
ISO copyright office
Case postale 56 � CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.ch
Web www.iso.ch
Printed in Switzerland
ii © ISO 2001 – All rights reserved

ISO 5802:2001(E)
Contents Page
Foreword.v
Introduction.vi
1 Scope .1
2 Normative references .1
3 Terms, definitions and symbols.1
3.1 Terms and definitions .1
3.2 Symbols .14
4 Quantities to be measured.18
5 General conditions and procedures concerning in situ tests .18
5.1 General recommendations .18
5.2 Selection of test point when only the system resistance can be varied.18
5.3 Fans fitted with adjustment devices.19
5.4 System throttling devices allowing the system resistance to be altered .19
5.5 Selection of the test point when the system resistance cannot be varied.19
5.6 When correction of the coefficient deduced from the test is not necessary .20
6 Instrumentation.20
6.1 Instrumentation for measurement of pressure.20
6.2 Measurement of air velocity .21
6.3 Measurement of temperature .23
6.4 Determination of density.24
6.5 Measurement of rotational speed .25
7 Determination of fan pressure.25
7.1 Location of pressure measurement plane .25
7.2 Measurement of fan pressure.27
8 Determination of flow rate .36
8.1 Choice of measuring method .36
8.2 Choice of measuring section.36
8.3 Determination of flowrate using differential pressure devices.38
8.4 Determination of flowrate by velocity area methods .38
9 Determination of power.54
9.1 Definition of performance characteristics relating to the power of a fan.54
9.2 Losses during transmission of power from the motor to the impeller .56
9.3 Methods for determination of power .56
9.4 Measuring instruments .59
9.5 Precautions to be taken during in situ tests.59
10 Uncertainty associated with the determination of fan performance.59
10.1 General.59
10.2 Performance errors .60
10.3 Uncertainty of measurement .60
10.4 Specified uncertainties .60
10.5 Analysis of uncertainty .60
Annex A (normative) Position of exploration lines for a marginal wall profile compatible with a general
power law.67
Annex B (normative) Determination of the position of the marginal exploration lines in cases not
covered by annex A.71
ISO 5802:2001(E)
Annex C (normative) Minimum straight lengths required upstream and downstream of the differential
pressure devices (DP device) used for flow measurement.74
Annex D (normative) Loss allowance for straight, smooth ducts and standardized airways .82
Annex E (normative) Rotating vane anemometer calibration.84
Bibliography .86
iv © ISO 2001 – All rights reserved

ISO 5802:2001(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 5802 was prepared by Technical Committee ISO/TC 117, Industrial fans.
Annexes A to E form a normative part of this International Standard.
ISO 5802:2001(E)
Introduction
The need to revise existing methods of site testing has been apparent for some time. Bearing in mind the extent of
these revisions, it was felt appropriate to expand the method of site testing into a "stand-alone" document. This
would enable the velocity area methods to be fully detailed for all commonly encountered airway cross-sections. It
would also allow the addition of descriptive annexes covering the selection of suitable measuring stations and
instrument calibration.
In accordance with recent International agreements, it will be noted that fan pressure is now defined as the
difference between stagnation pressure at the fan inlet and outlet. Stagnation pressure is the absolute pressure
which would be measured at a point in a flowing gas if it were brought to rest isentropically. For Mach numbers less
than 0,2 the gauge stagnation pressure is within 0,6 % of the total pressure.
Less emphasis is placed on the use of "fan static pressure" as this is a conventional quantity only. It is to be
anticipated that its use will cease with time. All fluid losses are essentially losses in stagnation pressure and this
has been reflected in the definitions now specified.
It should be recognized that the performance of a fan measured under site conditions will not necessarily be the
same as that determined from tests using standardized airways. The reasons for such differences are not only due
to the inherently lower accuracy of a site test, but also due to the so-called "system effect factor" or "installation
effect", where the ducting connections at fan inlet and/or outlet modify its performance. The need for good
connections cannot be understated. This International Standard specifies the use of "common parts" immediately
adjoining the fans for the consistent determination of pressure and also to ensure that air/gas is presented to the
fan as a symmetrical velocity profile free from swirl and undue distortion. Only if these conditions are met, will the
performance under site conditions equate with those measured in standardized airways.
It should also be noted that this International Standard specifies the positioning of velocity-area measuring points
according to log-Tchebycheff or log-linear rules. Arithmetic spacing can lead to considerable error unless a very
high number of point readings are taken. (These would then have to be plotted graphically and the area under the
curve obtained using planimetry. The true average velocity would be this area divided by the dimensional
ordinates).
It is outside the scope of this International Standard to assess the additional uncertainty where the lengths of
straight duct either side of the measuring station are less than those specified in annex C. Guidance is, however,
given in ISO/TR 5168 and ISO 7194, from which it will be seen that where a significant radial component exists,
uncertainties can considerably exceed the normally anticipated 4 % at 95 % confidence levels.
vi © ISO 2001 – All rights reserved

INTERNATIONAL STANDARD ISO 5802:2001(E)
Industrial fans — Performance testing in situ
1 Scope
This International Standard specifies tests for determining one or more performance characteristics of fans installed
in an operational circuit when handling a monophase fluid.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO 5167-1:1991, Measurement of fluid flow by means of pressure differential devices — Part 1: Orifice plates,
nozzles and Venturi tubes inserted in circular cross-section conduits running full.
ISO 5801:1997, Industrial fans — Performance testing using standardized airways.
IEC 60034-1, Rotating electrical machine — Part 1: Rating and performance.
IEC 60051-8, Direct acting indicating analogue electrical measuring instruments and their accessories — Part 8:
Special requirements for accessories.
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
The quantities referred to are time-averaged mean values. Fluctuations which affect the quantities being measured
may be accounted for by repeating measurements at appropriate time intervals. Mean values may then be
calculated which are taken as the steady-state value.
3.1.1
air
air or other gas, except when specifically referred to as atmospheric air
3.1.2
standard air
–3
atmospheric air having a density of exactly 1,2 kg�m
NOTE Atmospheric air at a temperature of 16 °C, a pressure of 100 000 Pa and a relative humidity of 65 %, has a density
–3
of 1,2 kg�m , but these conditions are not part of the definition.
ISO 5802:2001(E)
3.1.3
fan
rotary machine which maintains a continuous flow of air at a pressure ratio not normally exceeding 1,3
3.1.4
impeller
rotating part of a fan which, by means of its blades, transfers energy to the air
3.1.5
casing
those stationary parts of a fan which direct the flow of air from the fan inlet opening(s) to the fan outlet opening(s)
3.1.6
duct
airway in which the air velocity is comparable with that at the fan inlet or outlet
3.1.7
chamber
airway in which the air velocity is small compared with that at the fan inlet or outlet
3.1.8
transition piece
section
airway along which there is a gradual change of cross-sectional area and/or shape
3.1.9
test enclosure
room, or other space protected from draught, in which the fan and test airways are situated
3.1.10
area of the conduit section
A
x
area of the conduit at section x
3.1.11
fan inlet area
A
by convention, the gross area in the inlet plane inside the casing
NOTE The fan inlet plane should be taken as that surface bounded by the upstream extremity of the air moving device. In
this International Standard the fan inlet plane is indicated by plane 1 (see Figure 1).
3.1.12
fan outlet area
A
by convention, the gross area in the outlet plane inside the casing without deduction for motors, fairings or other
obstructions
NOTE The fan outlet plane should be taken as that surface bounded by the downstream extremity of the air moving
device. In this International Standard the outlet is indicated by plane 2 (see Figure 1).
3.1.13
temperature
t
air or fluid temperature measured by a temperature sensor
2 © ISO 2001 – All rights reserved

ISO 5802:2001(E)
a) Axial fan
b) Centrifugal fan
Key
1 Plane 1 5 Transition
2 Plane 2 6 Diffuser
3 Inlet box 7 Transition
4 Inlet duct 8 Outlet duct
Figure 1 — Location of pressure measurement planes for site testing
ISO 5802:2001(E)
3.1.14
absolute temperature
�
thermodynamic temperature measured above absolute zero
� = t+273,15
3.1.15
stagnation temperature at a point
�
sg
absolute temperature which results if an ideal gas flow is brought to rest isentropically without addition of energy or
heat
NOTE The stagnation temperature is constant along an airway, and for an inlet duct is equal to the absolute ambient
temperature in the test enclosure.
3.1.16
static or fluid temperature
�
absolute temperature of a thermal sensor moving at the fluid velocity
v
��� �
sg
2c
p
where � is the fluid velocity (m/s)
3.1.17
dry bulb temperature
t
d
air temperature measured by a dry temperature sensor in the test enclosure, near the fan inlet or airway inlet
3.1.18
wet bulb temperature
t
w
air temperature measured by a temperature sensor covered by a water-moistened wick and exposed to air in
motion
NOTE When properly measured, it is a close approximation of the temperature of adiabatic saturation.
3.1.19
stagnation temperature at a section
�
sgx
mean value in time of the stagnation temperature averaged over the area of the specified airway cross section
3.1.20
static or fluid temperature at a section
�
x
mean value in time of the static or fluid temperature averaged over the area of the specified airway cross section
3.1.21
specific gas constant
R
for an ideal gas, the equation of state is written
p
� R�
�
4 © ISO 2001 – All rights reserved

ISO 5802:2001(E)
3.1.22
inlet stagnation temperature
�
sg1
temperature in the test enclosure near the fan inlet or the inlet duct at a section where the fluid velocity is less than
25 m/s
NOTE In this case the stagnation temperature may be considered equal to the ambient temperature
���� t� 273,15
sg1 a a
3.1.23
isentropic exponent
�
for an ideal gas and an isentropic process
p
� constant
�
�
3.1.24
specific heat at constant pressure
c
p
for an ideal gas:
�
cR�
p
� � 1
3.1.25
specific heat at constant volume
c
V
for an ideal gas
R
c �
V
� � 1
3.1.26
compressibility factor
Z
p
Z �
�R�
p �
and Z is a function of the ratios and
p �
cc
where
p is the critical pressure of the gas
c
� is the critical temperature of the gas
c
NOTE For an ideal gas Z =1.
3.1.27
absolute pressure at a point
p
pressure measured from absolute zero, which is exerted at a point at rest relative to the air around it
ISO 5802:2001(E)
3.1.28
atmospheric pressure
p
a
absolute pressure of the free atmosphere at the mean altitude of the fan
3.1.29
gauge pressure
p
e
value of a pressure when the datum pressure is the atmospheric pressure at the point of measurement
NOTE It may be negative or positive:
p = p – p
e a
3.1.30
absolute stagnation pressure at a point
p
sg
absolute pressure which would be measured at a point in a flowing gas if it were brought to rest via an isentropic
process
�
��� � 1 ��1
pp��1 Ma
sg��
��2
where Ma is the Mach number at this point
3.1.31
dynamic pressure at a point
p
d
pressure calculated from the velocity� and the density� of the air at the point
�v
p �
d
3.1.32
total pressure at a point
p
t
absolute stagnation pressure minus the atmospheric pressure
p = p – p = p + p
t sg a e d
NOTE When the Mach number is less than 0,2, the Mach factor is less than 1,01 and the absolute stagnation pressure p
sg
is very close to the sum of the gauge pressure, the atmospheric pressure and the dynamic pressure:
p � p + p + p
sg e a d
3.1.33
average gauge pressure at a section x
p
ex
mean value in time of the gauge pressure averaged over the area of the specified airway cross section
3.1.34
average absolute pressure at a section x
p
x
mean value in time of the absolute pressure averaged over the area of the specified airway cross section
p = p + p
x ex a
6 © ISO 2001 – All rights reserved

ISO 5802:2001(E)
3.1.35
conventional dynamic pressure at a section x
p
dx
dynamic pressure calculated from the average velocity and the average density at the specified airway cross
section
��
vq1
mx m
p���
dx x
��
22� ��A
xx
3.1.36
fan dynamic pressure
p
dF
conventional dynamic pressure at the fan outlet calculated from the mass flow, the average air density at the outlet
and the fan outlet area
vq1��
m2 m
p���
dF 2
��
22���A
3.1.37
absolute stagnation pressure at a section x
p
sgx
sum of the conventional dynamic pressure p corrected by the Mach factor coefficient F at the section and the
dx Mx
average absolute pressure p
x
p = p + p F
sgx x dx Mx
NOTE The absolute stagnation pressure may be calculated by the expression:
�
��� � 1 ��1
pp��1 Ma
sgx x��x
��2
3.1.38
average total pressure at a section x
p
tx
when the Mach number is less than 0,122, the Mach factor F may be neglected so
M
p = p + p = p – p
tx ex dx sgx a
3.1.39
fan pressure
p
F
difference between the stagnation pressure at the fan outlet and the stagnation pressure at the fan inlet
p = p – p
F sg2 sg1
3.1.40
fan static pressure
p
sF
conventional quantity defined as the fan pressure minus the fan dynamic pressure corrected by the Mach factor at
the fan outlet area
p = p – p F – p = p – p
sF sg2 dF M2 sg1 2 sg1
ISO 5802:2001(E)
3.1.41
Mach number at a point
Ma
ratio of the fluid velocity at a point and the velocity of sound in the fluid
NOTE For an ideal gas:
v
Ma �
��R
w
3.1.42
Mach number at a section x
Ma
x
ratio of the fluid average velocity by the velocity of sound at the specified airway cross section
v
mx
Ma �
x
��R
wx
3.1.43
Mach factor
F
M
correction factor which is applied to the dynamic pressure at a point given by the expression
pp�
sg
F �
M
p
d
NOTE The Mach factor may be calculated by:
24 6
Ma Ma Ma
F ��1.� � �. for � =1,4
M
4 40 1600
3.1.44
stagnation inlet density
�
sg1
density calculated from the stagnation inlet pressure p and the stagnation inlet temperature �
sg1 sg1
p
sg1
� �
sg1
R �
wsg1
3.1.45
average density at a section x
�
x
fluid density calculated from the absolute pressure p and the static temperature �
x x
p
x
� �
x
R �
wx
3.1.46
mean density
�
m
arithmetic mean value of inlet and outlet densities
� � �
� �
m
8 © ISO 2001 – All rights reserved

ISO 5802:2001(E)
3.1.47
mean mass flowrate at a section
q
m
mean value over time of the mass of fluid which passes through the specified airway cross section per unit of time
NOTE The mass flow will be the same at all cross sections within the fan airway system, apart from leakage. When the fan
is not gastight, the mass flow is taken as either that at the fan inlet or outlet, as appropriate.
3.1.48
inlet stagnation volume flow
q
Vsg1
mass flowrate divided by the stagnation inlet density
q
m
q �
Vsg1
�
sg1
3.1.49
outlet stagnation volume flow
q
Vsg2
mass flowrate divided by the stagnation outlet density
q
m
q �
Vsg2
�
sg2
3.1.50
volume flow at a section x
q
Vx
mass flow at the specified airway cross section divided by the corresponding mean value in time of the average
density at that section
q
m
q �
V x
�
x
3.1.51
average velocity at a section x
�
mx
volume flow at the specified airway cross section divided by the cross-sectional area A
q
V x
v �
mx
A
x
NOTE This is the mean value over time of the average component of the fluid velocity normal to that section.
3.1.52
fan work per unit mass
y
mechanical energy increment per unit mass of the fluid passing through the fan
pp� v v
21 m2 m1
y�� �
� 22
m
NOTE y may be calculated as in 3.1.57.
ISO 5802:2001(E)
3.1.53
fan static work per unit mass
y
s
pp� v
21 m1
y��
s
� 2
m
3.1.54
fan pressure ratio
r
Fp
ratio of the average absolute stagnation pressure at the outlet section of a fan to that at its inlet section
p
sg2
r �
Fp
p
sg1
3.1.55
density ratio of inlet density to mean density
k
�
fluid density at the fan inlet divided by the mean density in the fan
2�
k �
�
� � �
3.1.56
compressibility coefficient
k
ratio of the mechanical work done by the fan on the air to the work that would be done on an incompressible fluid
with the same mass flow, inlet density and pressure ratio
NOTE 1 The work done is derived from the impeller power on the assumption of isentropic expansion with no heat transfer
through the fan casing.
NOTE 2 k is given by the expression:
(1���) Prlog
sg1 r 10 Fp
k �
(1����) Pr( 1)
��
sg1 r
�qp log 1�
��
m F10
�qp
��m F
3.1.57
fan air power
P
u
conventional output power which is the product of the mass flow by the fan work per unit mass or the product of the
inlet volume flow, the compressibility coefficient k andthefanpressure
P = q y � q p k
u m Vsg1 F
3.1.58
fan static air power
P
us
conventional output power which is the product of the mass flow q by the fan static work per unit mass or the
m
product of the inlet volume flow, the compressibility coefficient k and the fan static pressure p
sF
P = q y � q kp
us m s Vsg1 sF
10 © ISO 2001 – All rights reserved

ISO 5802:2001(E)
3.1.59
impeller power
P
r
mechanical power supplied to the fan impeller
3.1.60
fan shaft power
P
a
mechanical power supplied to fan shaft
3.1.61
motor output power
P
o
shaft power output of the motor or other prime mover
3.1.62
motor input power
P
e
electrical power supplied at the terminals of an electric motor drive
NOTE With other drive forms it is not usual to express the input to the prime mover in terms of power.
3.1.63
rotational speed
N
number of revolutions of the fan impeller per minute
3.1.64
rotational frequency
n
number of revolutions of the fan impeller per second
3.1.65
tip speed
u
peripheral velocity of the impeller blade tips
3.1.66
peripheral Mach number
Ma
u
non-dimensional parameter equal to the ratio of the tip speed to the velocity of sound in the gas at the stagnation
conditions of fan inlet
u
Ma �
u
��R
wsg1
3.1.67
fan Mach number
Ma
F
conventional quantity used as a scaling parameter
NOTE It is the fan tip speed divided by the speed of sound in standard air:
�Dn
r
Ma �
F
c
–1
where c = 340 m�s for ambient temperature.
ISO 5802:2001(E)
3.1.68
fan impeller efficiency
�
r
fan air power P divided by the impeller power P
u r
3.1.69
fan impeller static efficiency
�
sr
fan static power P divided by the impeller power P
us r
3.1.70
fan shaft efficiency
�
a
fan air power P divided by the shaft power P
u a
NOTE The fan shaft power P includes bearing losses whilst the impeller power does not.
a
3.1.71
fan motor efficiency
�
M
fan air power P divided by the motor output power P
u o
3.1.72
overall efficiency
�
e
fan air power P divided by the input power for the fan and motor combination
u
3.1.73
kinetic energy factor at a section x of area A
x
�
Ax
non-dimensional coefficient equal to the time-averaged flux of kinetic energy per unit mass through the considered
area A divided by the kinetic energy per unit mass corresponding to the mean air velocity through this area
x
()�vvdA
nx
��
A
x
� �
Ax
qv
m mx
where
� is the local absolute velocity
� is the local velocity component normal to the cross section
n
NOTE It has been agreed for this International Standard that by convention in fan technology� equals one.
Ax
3.1.74
kinetic index at a section x
i
kx
non-dimensional coefficient equal to the ratio of the kinetic energy per unit mass at the section x and the fan work
per unit mass
v
mx
i �
kx
2 y
12 © ISO 2001 – All rights reserved

ISO 5802:2001(E)
3.1.75
Reynolds number at a section x
Re
x
product of the local velocity, the local density and a relevant scale length (duct diameter, blade chord) divided by
the dynamic viscosity
� vD
xmx x
Re �
x
�
x
NOTE It is a non-dimensional parameter which defines the state of development of a flow and is used as a scaling
parameter.
3.1.76
fan Reynolds number
Re
F
product of the fan tip speed, the inlet density and the impeller diameter divided by the dynamic viscosity of the fluid
at the fan inlet
� �nD
1r
Re �
F
�
NOTE It is a conventional quantity used as a scaling parameter.
3.1.77
friction loss coefficient
(� )
x-y y
non-dimensional coefficient for friction losses between sections x and y of a duct, calculated for the velocity and
density at section y
NOTE For incompressible flow:
�pv���()
xy��y my x y y
3.1.78
fan flow coefficient
�
non-dimensional quantity equal to the mass flowrate divided by the product of the mean density, the peripheral
speed of the impeller and the square of the diameter of the impeller
q
m
� �
� uD
mr
3.1.79
fan work per unit mass coefficient
�
non-dimensional quantity equal to the fan work per unit mass divided by the square of the peripheral speed of the
impeller
y
� �
u
ISO 5802:2001(E)
3.1.80
fan power coefficient
�
P
non-dimensional quantity equal to the impeller power divided by the product of the mean density with the cube of
the peripheral speed of the impeller and the square of the diameter of the impeller
P
r
� �
P
� uD
mr
3.2 Symbols
A
Area of the conduit section m
A Area of the conduit of section x m
x
A Correcting coefficient for partial pressure of water vapour at a given temperature
w
A Fan inlet area m
A Fan outlet area
m
b Distance from the wall to the nearest measuring point m
–1
c Speed of sound in air
m�s
–1 –1
c Specific heat at constant pressure
J�kg �K
p
–1 –1
c Specific heat at constant volume
J�kg �K
V
d Diameter of the head of the velocity probe mm
D
Internal diameter of a circular cross-section duct m
D Minimum inner diameter of an annular duct m
a
D Equivalent diameter of a non-circular cross-section duct m
e
D Hydraulic diameter of the duct m
h
D Diameter of the impeller m
r
e Thickness of the ring in an annular duct m
e
Fan pressure uncertainty
pF
e
Flowrate uncertainty
q
e Characteristic uncertainty
�
f Additional uncertainty
f Weighting coefficient
i
F Proximity coefficient
F Mach factor
M
–2
g
Gravitational acceleration m�s
h
Horizontal distance of the probe from the reference wall when the orthogonal
coordinates are used m
��
p
v
h Relative humidity h �
u
u
��
p
��
sat
H
Height of the rectangular section of a duct m
i Discharge kinetic index
k
14 © ISO 2001 – All rights reserved

ISO 5802:2001(E)
i Kinetic index at section x
kx
I Line current A
k Compressibility coefficient
k Density ratio
�
l Length of traverse line m
l Length of traverse line at distance a from reference wall
m
a
l
Length of traverse line at distance 0 from reference wall m
l
Length of traverse line at distance x from reference wall m
x
L Length of the rectangular section of a duct, or greatest possible length of a section
having any one form m
L Length of a duct m
D
L Inner dimension of the duct in a direction perpendicular to the nearest wall to the
p
probe m
Ma Mach number at a point
Ma Fan Mach number
F
Ma Mach number at section x
x
–1
n Rotational frequency of impeller
r�s
–1
N Rotational speed of impeller
r�min
N Number of traverse lines
r
p Mean pressure in space and time of the fluid, i.e. absolute static pressure Pa
p Atmospheric pressure (absolute) Pa
a
p Dynamic pressure at a point Pa
d
p Dynamic pressure at section x Pa
dx
p Fan dynamic pressure Pa
dF
p Gauge pressure Pa
e
p Gauge stagnation pressure at section x Pa
esgx
p Average gauge pressure at section x Pa
eX
p Fan (stagnation) pressure Pa
F
p Inverse of the exponent of the characteristic law of the evolution of velocities at the
l
wall (taking into account the measurement results of the surface roughness of the
walls and the value of the Reynolds numbers)
p Saturation vapour pressure Pa
sat
p Fan static pressure Pa
sF
p Absolute stagnation pressure at a point Pa
sg
p Absolute stagnation pressure at section x Pa
sgx
p Total pressure at a point Pa
t
p Total pressure at section x Pa
tx
p Partial pressure of water vapour Pa
v
p Average absolute pressure at section x Pa
x
p Absolute static pressure in the inlet section Pa
p Absolute static pressure in the outlet section Pa
P Mechanical power output to the fan shaft W
a
ISO 5802:2001(E)
P Motor input power W
e
P Friction losses power W
f
P Power available at the output shaft of the drive W
o
P Mechanical power supplied to the impeller of the fan W
r
P Fan air power W
u
P Fan static power W
us
–1
q
mass flowrate kg�s
m
3 –1
q
Volume flowrate m �s
V
3 –1
q
Actual volume flowrate m �s
Vr
3 –1
q Volume flowrate corresponding to standardized conditions of use of the DP device
m �s
Vs
3 –1
q Volume flowrate at the inlet at stagnation conditions
m �s
Vsg1
3 –1
q Volume flowrate at the outlet at stagnation conditions
m �s
Vsg2
3 –1
q Volume flowrate at section x
m �s
Vx
r Radius of the duct m
r
Fan pressure ratio
Fp
r
Area ratio of an orifice plate
A
–1 –1
R
Specific gas constant J�kg �K
R Extreme value of a duct radius m
D
Re Reynolds number at section x
x
–1 –1
R Specific gas constant of humid air
J�kg �K
w
S Characteristic proportional slope of equivalent orifice
t Air or fluid temperature measured by a temperature sensor °C
t Dry bulb temperature °C
d
t Static temperature at section x °C
x
t Wet bulb temperature °C
w
–1
u Peripheral speed of the impeller
m�s
U Voltage of electrical current
–1
Local absolute velocity
� m�s
–1
Axial velocity at test section
� m�s
a
–1
� Mean value of � over time m�s
m
–1
� Mean value of � in the inlet section over time m�s
m1
–1
�
Mean value of � in the outlet section over time m�s
m2
–1
� Mean value of � in section x over time m�s
mx
–1
Local velocity normal to the cross-section
� m�s
n
–1
Profile of velocities along the segment of the exploration line of the abscissa x
� (y) m�s
x
V Volume of fluid m
y
Vertical distance of the probe from the reference wall when orthogonal coordinates
are used m
–1
y
Fan work per unit mass J�kg
F
–1
y
Fan static work per unit mass J�kg
Fs
z Mean altitude of the fan from reference plane m
16 © ISO 2001 – All rights reserved

ISO 5802:2001(E)
z Mean altitude of fan inlet from reference plane m
z Mean altitude of fan outlet from reference plane m
Z Compressibility factor
Kinetic energy coefficient of the flow
�
A
�
Value of the coefficient � in the inlet section of area A
A1
� Value of the coefficient � in the outlet section of area A
A2
3 –1
Absolute uncertainty in the volume flowrate q
�q
V m �s
V
Differential pressure Pa
�p
3 –1
Absolute limit error on the determination of the volume flowrate q
�q m �s
V
V
Altitude at barometer minus altitude of fan m
�z
Expansion factor
�
Fan shaft efficiency
�
a
� Overall efficiency (or unit efficiency)
e
� Motor shaft efficiency
Ms
� Motor efficiency
M
Fan impeller efficiency
�
r
Fan impeller static efficiency
�
sr
Drive efficiency
�
tr
Ratio of specific heats (at constant pressure and volume)
�
� Darcy friction factor
� Fan power coefficient
P
�1
� Friction loss coefficient (� =��L�D )
h
Dynamic viscosity of the fluid at section x Pa·s
�
x
Dynamic viscosity of the fluid at the fan inlet Pa·s
�
–3
Density of fluid
� kg�m
–3
Mean density
� kg�m
m
–3
� Arithmetic mean value over time of inlet and outlet densities
kg�m
–3
� Average density at section x kg�m
x
–3
Mean density in the inlet section
� kg�m
–3
Mean density in the outlet section
� kg�m
–3
Stagnation inlet density
� kg�m
sg1
Absolute temperature K
�
� Stagnation temperature at a point K
sg
� Stagnation temperature at section x K
sgx
Static or fluid temperature at section x K
�
x
Fan flow coefficient
�
Azimuth radians
�
Fan work per unit mass coefficient
�
ISO 5802:2001(E)
4 Quantities to be measured
The flow of fluid in a fan and in the installation it serves is never completely steady. However, the quantities relating
to the state and displacement which characterize this flow do have steady mean values over time, at least in the
normal operating zone of the fan, when the system resistance is kept constant and the rotational speed of the fan is
maintained to within 0,5 %.
The fluctuations which affect the characteristics investigated may be taken into account by repeating the
measurements at appropriate intervals of time so that mean values may be calculated truly representing the
desired mean values over time, which then become virtually steady values.
For a permanent flow of fluid of this nature generated by an industrial fan operating in an airtight section of an
airway without a branch pipe (inlet section 1; outlet section 2 of Figure 1), the following expression serves as a
basis for defining the effect of the fan on the flow under consideration:
P pp� ��v v
u 21AA2m2 1m1
yg�� � � �()z�z
q � 22
m m
By convention, for this International Standard� =� =1
A2 A1
5 General conditions and procedures concerning in situ tests
5.1 General recommendations
Tests on site shall be carried out after an initial check that the fan is functioning properly.
There shall be no significant leakage of gas into or out of the airway between the fan and any flow or pressure
measuring plane. There shall be no unintended recirculation of gas between the inlet and outlet of the fan.
The measures necessary for the safety of the test operators and for the prevention of damage to the fan shall not
have any appreciable effect on the performance characteristics of the machine under test.
Before beginning the acceptance tests, the supplier shall have the right to check that the fan is in good working
order and to make any necessary adjustments.
5.2 Selection of test point when only the system resistance can be varied
If, fo
...