SIST EN 12589:2001

SLOVENSKI STANDARD
SIST EN 12589:2001
01-december-2001
3UH]UDþHYDQMHVWDYE1DSUDYH]DUD]YRG]UDND$HURGLQDPLþQRSUHVNXãDQMHLQ
RFHQLWHYHQRW]DNRQVWDQWQRLQVSUHPHQOMLYRNROLþLQR]UDND
Ventilation for buildings - Air terminal units - Aerodynamic testing and rating of constant
and variable rate terminal units
Lüftung von Gebäuden - Luftdurchlasseinheiten - Aerodynamische Prüfung und
Bewertung von Luftdurchlasseinheiten mit konstantem und variablem Luftvolumenstrom
Ventilation des bâtiments - Unités terminales - Essais aérodynamiques et évaluation des
unités terminales a débit constant et variable
Ta slovenski standard je istoveten z: EN 12589:2001
ICS:
91.140.30 3UH]UDþHYDOQLLQNOLPDWVNL Ventilation and air-
VLVWHPL conditioning
SIST EN 12589:2001 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 12589:2001

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SIST EN 12589:2001
EUROPEAN STANDARD
EN 12589
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2001
ICS 91.140.30
English version
Ventilation for buildings - Air terminal units - Aerodynamic testing
and rating of constant and variable rate terminal units
Ventilation des bâtiments - Unités terminales - Essais Lüftung von Gebäuden - Luftdurchlasseinheiten -
aérodynamiques et évaluation des unités terminales à débit Aerodynamische Prüfung und Bewertung von
constant et variable Luftdurchlasseinheiten mit konstantem und variablem
Luftvolumenstrom
This European Standard was approved by CEN on 18 August 2001.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, 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
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12589:2001 E
worldwide for CEN national Members.

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SIST EN 12589:2001
EN 12589:2001 (E)
Contents
PAGE
FOREWORD. 3
1 SCOPE. 4
2 NORMATIVE REFERENCES . 4
3 TERMS, DEFINITIONS AND SYMBOLS. 6
4 INSTRUMENTATION. 7
5 TESTS FOR FLOW RATE CONTROL CHARACTERISTICS . 8
6 TESTS TO DETERMINE INDUCED AIR FLOW RATE . 20
7 TEST TO DETERMINE TEMPERATURE MIXING . 22
8 TESTS TO DETERMINE LEAKAGE RATES . 27
ANNEX A (NORMATIVE) DETERMINATION OF STATIC PRESSURE . 32
2

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SIST EN 12589:2001
EN 12589:2001 (E)
Foreword
This European Standard 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 March 2002, and conflicting national standards shall
be withdrawn at the latest by March 2002.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
3

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SIST EN 12589:2001
EN 12589:2001 (E)
1 Scope
This European Standard specifies methods for the aerodynamic testing and rating of constant and
variable flow rate terminal units suitable for use with air distribution systems.
The terminal units considered are:
- Single and dual duct.
- Induction.
- Fan assisted induction (parallel and series).
- Single duct with integral diffuser.
The tests for each type of unit are summarized in Figure 1.
The tests in this standard are designed to determine fully the aerodynamic performance of terminal units
and provide a basis for the comparison of the suitability of such assemblies when correctly installed in an
air distribution system.
2 Normative references
This European Standard incorporated by dated or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references the subsequent amendments to or revisions of any of these publications
apply to this European Standard only when incorporated in it by amendment or revision. For undated
references the latest edition of the publication referred to applies (including amendments).
CR 12792 Ventilation for buildings - Symbols, units and terminology
ISO 5167-1 Measurement of fluid flow by means of pressure differential devices -
Part 1 : Orifice plates, nozzles and venturic tubes inserted in circular cross-section
conduits running full
ISO 3966 Measurement of fluid flow in closed conduits – Velocity area method using Pitot static
tubes
ISO 5221 Air distribution and air diffusion - Rules to methods of measuring air flow rate in an air
handling duct
4

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SIST EN 12589:2001
EN 12589:2001 (E)
Single duct Dual duct Induction Fan assisted Fan assisted Terminal with
Induction Induction integral diffuser
Terminal Terminal
Series type Parallel type
SD DD IU IFS IFP TD
5
6
Flow rate control characteristic INDUCED FLOW RATE
All units
Press. Compensation
5.3 5.4
Influence inlet cond.
min. Operat. Press
All units
Unit SD, DD
Unit IU, IFS, IFP
Unit TD
78Temperature mixing Leakage rates
All units
8.3 8.5
Damper Casing
All units All units
Figure 1 - Test units and test requirements
5

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SIST EN 12589:2001
EN 12589:2001 (E)
3 Terms, definitions and symbols
3.1 For the purposes of this standard, the terms and definitions given in CR 12792 apply.
3.2 The symbols and the suffixes used in this standard are shown in Tables 1 and 2
respectively.
Table 1 - Symbols used for testing air terminal units
Symbol Quantity Units
2
A Internal cross-sectional area of duct m
c
d m
e
Equivalent diameter 4A /

c
p Absolute static pressure Pa
p Atmospheric pressure Pa
a
p Velocity pressure Pa
d
p Stagnation (or absolute total pressure) Pa
r
p Static gauge pressure (p - p)Pa
s a
p Total pressure (p - p)Pa
t r a

 Flow meter pressure difference Pa

 Total pressure difference Pa
t
3 -1 -1
q Volume rate of air flow at the flow meter m .s or l.s
v
3 -1 -1
q Leakage volume rate of air flow m .s or l.s
vL
3 -1 -2
Q Leakage volume rate of air flow across a m .s .m
vLBA
valve per unit cross-sectional area
-1 -2
or l.s .m
3 -1 -2
Q Leakage volume rate of air flow through m .s .m
vLCA
casing per unit cross-sectional area
-1 -2
or l.s .m
-1
v Velocity m.s
-3
 Air density kg.m
 Celsius temperature
C
S Position of valve or induction damper setting

n Fan speed control setting V or position
Table 2 - Suffixes used with the symbols in Table 1
0 recommended value (usually by the manufacturer)
1 inlet of the unit under test
2 outlet of the unit under test
3 induction port(s) of the unit under test
i outlet air temperature
c cold side of the unit under test
w warm side of the unit under test
u measuring point upstream of the flow meter
D measuring point upstream of the discharge flow meter
sn nett surface area of the unit under test
ca casing of the unit under test
va valve of the unit under test
6

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SIST EN 12589:2001
EN 12589:2001 (E)
4 Instrumentation
4.1 Air flow rate measurement
4.1.1 The air flow rate shall be measured using instruments in accordance with ISO 5167-1.
4.1.2 Air flow meters shall have the ranges and accuracies shown in Table 3.
Table 3 Ranges and accuracies of air flow meters

Range Measurement error
3 -1
m s %
± 5
> 0,007  0,07
± 2,5
> 0,07  7,00
NOTE Flow meters may be calibrated in situ by means of pitot static tube traverse techniques described in
ISO 3966.
4.1.3 Leakage air flow meters shall have the ranges and accuracies shown in Table 4.
Table 4  Ranges and accuracies of leakage air flow meters
Range Measurement error
3 -1
%
m s
-3 3 -1
0,9 x 10 m .s
 0,018
± 5 %
> 0.018
NOTE Alternatively, other devices such as variable-area, flow-rate meters or integrating air flow meters of the
positive displacement type may be used if calibrated in accordance with 4.1.3.
4.1.4 Flow meters shall be checked at intervals, as appropriate, but not exceeding 12 months. This
check may take the form of one of the following:
a) a dimensional check for all flow meters not requiring calibration;
b) a check calibration over their full range using the original method employed for initial calibration
or meters calibrated in situ;
c) a check against a flow meter which meets the flow meter specification in accordance with
ISO 5221.
7

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SIST EN 12589:2001
EN 12589:2001 (E)
4.2 Pressure measurement
4.2.1 Pressure in the duct shall be measured by means of a liquid-filled calibrated manometer, or
any other device conforming to 4.2.2.
4.2.2 The maximum scale or display interval shall not be greater than the characteristics listed for
the accompanying range of manometers, shown in Table 5.
Table 5  Maximum scale or display interval
Range Maximum scale interval
Pa Pa
1,0
 25
2,5
> 25 to 250
5,0
> 250 to 500
25,0
> 500
4.2.3 For air flow rate measurements, the minimum pressure differential shall be:
a) 25 Pa with an inclined tube manometer or micro-manometer;
b) 500 Pa with a vertical tube manometer.
4.2.4 The calibration standards shall be:
a) for instruments with the range up to 25 Pa, a micro-manometer accurate to ± 0,5 Pa;
b) for instruments with the range of 25 Pa to 500 Pa, a manometer accurate to ± 2,6 Pa (hook
gauge or micro-manometer);
c) for instruments with the range of 500 Pa and upwards, a manometer accurate to ± 25 Pa
(vertical manometer).
4.3 Temperature measurement
Measurement of temperature shall be by means of mercury-in-glass thermometers, resistance
thermometers or thermo-couples. Instruments shall be graduated to give readings in intervals not greater
than 0,5 K and calibrated to an accuracy of ± 0,25 K.
5 Tests for flow rate control characteristics
5.1 Principle
To determine the changes in primary air flow rate resulting either from variations in the pressure
differential between the inlet duct(s) and the outlet duct(s) or chamber or upstream pressure whichever is
appropriate.
Also, to determine the pressure differential between upstream and downstream of the terminal unit, and
additionally the minimum pressure difference which is necessary to reach the performance of the terminal
unit within the specified operating tolerances (minimum operating pressure difference).
8

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SIST EN 12589:2001
EN 12589:2001 (E)
5.2 Test measurements
The following parameters shall be measured during the tests:
a) p inlet duct static gauge pressure.
s1
b) p static gauge pressure in the chamber into which the outlet duct discharges
s2
(p = 0 if free outlet conditions are used).
s2
c)  air temperature at the inlet to the unit under test.
1
d)  p the flow meter pressure difference (or the appropriate parameter that relates
to the air flow q ).
v1
e) p the static gauge pressure immediately upstream of the flow meter.
su
f)  the air temperature immediately upstream of the flow meter.
u
g) p the atmospheric pressure at the beginning and end of the tests.
a
5.3


   


p )
tmin
5.3.1 Units without induction SD, DD
NOTE This test is required for pressure independent units only.
5.3.1.1 Test installation
A typical test installation for type SD units is shown in Figure 2.
Performance of static pressure measurement device is described in annex A.
A typical test installation for type DD units is shown in Figure 3. All the test equipment described in clause
4 should be installed for both supply ducts. Discharge temperature measurement equipment should be
installed if mixing efficiency is to be determined.
5.3.1.2 Test procedure
5.3.1.2.1 With the supply fan running, set the flow rate controller to its maximum setting. Increase the
pressure differential between the inlet(s) and the outlet(s) to the manufacturers recommended maximum
operating pressure differential and record the test measurements in accordance with 5.2.
5.3.1.2.2 Decrease the pressure differential in stages, approximately to the values given in Table 6
until the flow rate has reached a value equal to or less than 50 % of the value obtained in the
pressure differential range where the flow rate is seen to be approximately constant. At each stage
record the test measurements in accordance with 5.2.
When making the adjustments to pressure, if the pressure falls below the next prescribed value,
increase it to the value at the start of the test, and then slowly decrease it to the specified value before
a further measurement is taken.
9

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SIST EN 12589:2001
Q
D
Q
EN 12589:2001 (E)
4
3
5
3 d
d
e1
e2
2
1,5 d
e1
7
1 t t
6
u
1
8
Key
1 Air flow 5 Total length of unit
2 Flow rate measuring device which conforms to ISO 5167-1 6 Unit under test
3 Flow straughtener which conforms to ISO 5167-1 7 Chamber such as reverberation room
4 This length to be straight and its cross section uniform and equal to that of the inlet spigot 8 Peizometric ring
NOTE Dual duct unit: Each duct to be measured seperately
Figure 2
Typical test installation to determine flow rate control characteristics for units SD; DD and damper leakage characteristics for all units
10
p
d
e1
P
s1
P
s2
d
e2

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SIST EN 12589:2001
Q Q
Q
D D
Q
EN 12589:2001 (E)
3
2
4
3 d
e1
> 1d
- e2
u
w
1,5 d
1w
e1
> 0,5 d
1 - e2
5
8
7
X
u
c
9
6
1c
< 100
-
> 25
-
a/4 a/4
12
11
11
r
a
R 0,7
13
X
Key
1 Heat exchanger 8 Piezometric ring
2 Flow straughtener which conforms to ISO 5167-1
9 Flow rate measuring device which conforms to ISO
5167-1
3 This length to be straight and its cross section uniform and equal to that of the inlet spigot
10 Points of measurement in outlet duct
4 Total length of unit 11 Temperature stations in rectangular duct
5 Total length of unit 12 Temperature stations in circular duc
6 Outlet duct internal dimensions equal to those of unit outlet 13 Points of measurement in inlet duct(s) or outlet
duct(s) extension of multiple outlet unit
7 Unit under test
Figure 3
Typical installation to determine temperature mixing efficiency DD; IU; IFS; IFP
11
>25
-
<100
-
p p
c
w
p
s1w
p
s1c
d d
e1w
e1c
b
b/4 b/4
d
e2
R 0,7

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SIST EN 12589:2001
EN 12589:2001 (E)
5.3.1.2.3 Reduce the pressure differential to zero, and then restore it the level at which the last
measurement was made. Increase the pressure differential in stages approximately to the values given in
Table 6 until the maximum pressure differential is reached. At each stage record the test measurements
in accordance with 5.2.
When making the adjustments to pressure, if the pressure rises above the next specified value, reduce it
to zero and then slowly increase it to the specified value before a further measurement is taken.
Table 6
Pressure differentials (Values in R10 series)
2 000; 1 600; 1 250; 1 000; 800; 630; 500; 400; 315; 250; 200; 125; 63; in Pa
5.3.1.2.4 Repeat procedures 5.3.1.2.2 and 5.3.1.2.3 for flow rates at mid-range and minimum settings
as typically shown in Figure 4.
5.3.1.2.5 Dual duct units with mixing dampers and separate air flow rate controller: repeat procedures
5.3.1.2.2 and 5.3.1.2.3 for mixing valve settings at approximately 100 %; 75 %; 25 % and 0 %. In the
case of a VAV-dual duct unit, repeat this procedure for the maximum and minimum flow rate setting.
For dual ducts, with air flow rate controllers for each supply duct, see 5.3.1.2.4.
5.3.2 Units with induction IU, IFS, IFP
NOTE This test is required for pressure independent units only.
5.3.2.1 Test installation
A typical test installation is shown in Figure 5. Performance of static pressure measurement device is
described in annex A.
Test procedure
5.3.2.2
5.3.2.2.1 The parameters applicable for each type of unit to be tested are shown in Table 7.
12

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SIST EN 12589:2001
EN 12589:2001 (E)
13


Figure 4b) Example of determination of mean air flow rate and flow rate deviation as function of various
minimum operating pressures

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SIST EN 12589:2001
D
Q
Q
q
Q
Q
D
EN 12589:2001 (E)
3
2
> 3 d
-
e2
4
3 d
> 2,5 d
e1 -
e2
5
1
2
1,5 d
D
e1
t 8 t
t t
67
u
9
1
1
t
10
10
3
11
Key
1 Flow rate measuring device which conforms to ISO 5167-1 7 Unit under test
8 Total air flow 8 Total air flow
3 This length to be straight and its cross section uniform and equal to that of the inlet spigot 9 Heat exchanger
4 Total length of unit 10 Piezometric ring
5 Auxiliary fan 11 Induced air flow
6 Air flow
NOTE See Figure 3 for positions of temperature measurement stations
Figure 5
Typical installation with induced air flow, using an auxiliary fan. Types IU; IFS; IFP
14
p
1
d
e1
p
s1
p d
s2
e2
p
2

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SIST EN 12589:2001
EN 12589:2001 (E)
Table 7
Conditions for testing induction IU, IFS and IFP units
Unit Induction Auxiliary fan Unit Measurement
a
type inlet Status fan
IU sealed on or off - q = f (p - p )
v s2 s1
IFP sealed on or off off q = f (p - p )
v s2 s1
on, and adjust together with unit fan
to provide maximum prim. air flow
IFS open on q = f (p )
v s1
rate in discharge duct with Ps2 -
50 Pa
a
See Figure 5.
With the supply fan running, set the flow controller to its maximum setting. Increase the pressure
differential between the inlet and the outlet or the upstream pressure to the manufacturer's recommended
maximum operating pressure differential, and record the test measurements in accordance with 5.2.
5.3.2.2.2 Decrease the pressure differential in stages, approximately to the values given in Table 6,
until the flow rate has reached a value equal to or less than 50 % of the value obtained in the
pressure differential range where the flow rate is seen to be approximately constant. At each stage
record the test measurements in accordance with 5.2.
When making the adjustments to pressure, if the pressure falls below the next specified value, increase it
to the value at the start of the test, and then slowly reduce it to the specified value before a further
measurement is taken.
5.3.2.2.3 Calculate the flow rate at unit under test according to formula (1).
5.3.2.2.4 Repeat procedures 5.3.2.2.2 and 5.3.2.2.3 for flow rates at mid-range and minimum
settings as typically shown in Figure 4.
5.3.3 Units with integral diffuser and outlet damper, TD
NOTE This test is required for pressure independent units only.
5.3.3.1 Test installation
A typical test installation is shown in Figure 6.
Performance of static pressure measurement device is described in annex A.
5.3.3.2 Test procedure
5.3.3.2.1 Calculate q = v  A , where v is the manufacturer's maximum recommended velocity.
v0 0 0 0
With the supply fan running, set the auxiliary constant flow rate controller q = q - q , where q is the
v2 v0 v1 v1
maximum recommended flow rate of unit under test.
Set the flow rate controller of unit under test to its maximum setting. Increase the pressure differential
between the inlet and the outlet to the manufacturer's recommended maximum operating pressure
differential, and record the test measurements in accordance with 5.2.
5.3.3.2.2 Decrease the pressure differential in stages, approximately to the values given in
Table 6, until the flow rate has reached a value equal to or less than 50 % of the value obtained in the
pressure differential range, where the flow rate is seen to be approximately constant. At each stage
record the test measurements in accordance with 5.2.
Calculate the flow rate of unit under test as
15

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SIST EN 12589:2001
EN 12589:2001 (E)
q = q - q (1)
v1 v0 v2
When making the adjustments to pressure, if the pressure falls below the next specified value, increase it
to the value at the start of the test and then slowly reduce it to the specified value before a further
measurement is taken.
5.3.3.2.3 Reduce the pressure differential to zero, and then restore it to the level at which the last
measurement was made. Increase the pressure differential in stages, approximately to the values
given in Table 6, until the maximum pressure differential is reached. At each stage record the test
measurements in accordance with 5.2.
Calculate the flow rate at unit under test according to formula (1).
When making the adjustments to pressure, if the pressure rises above the next specified value, reduce it
to zero, and then slowly increase it to the specified value before a further measurement is taken.
5.3.3.2.4 Repeat procedures 5.3.3.2.2 and 5.3.3.2.3 for flow rates of unit under test at mid-range
and minimum settings as typically shown in Figure 4.
5.3.3.2.5 Repeat the test procedure as specified in 5.3.3.2 with the auxiliary constant flow rate
controller setting of half of the manufacturer's recommended maximum velocity.
q = q - q (2)
v0 v2 v1
5.3.3.2.6 Repeat the test procedure as specified in 5.3.3.2 with the auxiliary flow rate controller
discharge sealed (q = 0).
v2
5.4 Influence of 90 radiused bend
5.4.1 Principle
Non uniform flow conditions in the inlet duct to the unit can influence the flow rate control characteristics.
This section deals with the evaluation of an upstream 90 bend. If appropriate other non-straight duct
configurations can be dealt with in a similar way.
5.4.2 Test measurements
5.4.2.1 General
Test measurements shall be made in accordance with 5.2.
5.4.2.2 All units
5.4.2.2.1 Test installation
A typical test installation is shown in Figure 7.
The test shall be conducted with the supply duct in both the horizontal and vertical axis.
5.4.2.2.2 Test procedure
Repeat the tests as specified in 5.3.
16

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SIST EN 12589:2001
D
Q
D
Q
EN 12589:2001 (E)
4
3
7
3d
e1
2
A
o
5
6
v
o
1,5 d
> 2,5 d
e1
- e2
q
vo
1
q
v2
tt
1
8
u
2
6
Key
1Air flow 5 Total length of unit
2 Flow rate measuring device which conforms to ISO 5167-1 6 Piezometric ring
3 Flow straughtener which conforms to ISO 5167-1 7 Auxiliary constant flow rate controller
4 This length to be straight and its cross section uniform and equal to that of the inlet spigot 8 Unit under test as illustrated in Figure 1
Figure 6
Typical installation to determine flow rate control characteristics for units with integral diffuser and outlet damper TD
17
p
0
D
eO
p
s1
q
v1
p
s2
p
2

---------------------- Page: 19 ----------------------

d
e1
SIST EN 12589:2001
EN 12589:2001 (E)
3
2
d
e2
A
A
1
t
Q
1
4
9
5
d
e1
8
7
t
D
Q
u
6
Key
1 Sheet metal pressed bend 6 Air flow
2 This length to be specified by the 7 Flow rate measuring device which conforms to
manufacturer ISO 5167-1
3 Total length of unit 8 Flow straughtener which conforms to
ISO 5167-1
4 Unit under test 9 This length to be straight and its cross section
uniform and equal to that of the inlet spigot
5 Piezometric ring
NOTE 1 Dual duct unit: Each duct to be measured seperately
NOTE 2 Repeat procedure with test unit turned through 90
on axis A-A
Figure 7  90
radiused bend upstream condition for units SD; DD; IU; IFS; IFP
18
3 d
e1
1,5 d
e1
p
p s1
d
e2

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SIST EN 12589:2001
EN 12589:2001 (E)
5.5 Calculation of test results
5.5.1 Correction to volume flow rate density variation
Determine the volume air flow rate at the flow meter (q ). If there are significant differences in the
v
air temperature and atmospheric pressure between the flow meter and the unit under test, such
that the air density ratio
/
is less than 0,98 or greater than 1,02, apply the following correction:
u 1
q = q 
/
1(3)
v v1 u
where
 Psu + Pa
3
-

= 3,48   (4)
10
u

+ 273
u


and
 Ps1 + Pa
3
-

= 3,48   (5)
10
1

+ 273
1


Otherwise, q may be taken as equal to q



For standard reference conditions
 
 1 1
2
1

= ( - ) + q - (6)
 p p p
t
1
s s
1 2 2 2
2
A A
1 2


5.5.2


   



), mean air flow
t min
rate ( ) and deviation of air flow rate ( %).
q 

Draw a graph of  , against q as shown in Figure 4 for each test carried out.
t

Determine, at each air flow rate setting for several selected pressure difference ranges, the mean
air flow rate and  % (See example in Figure 4).
q q


where q is the maximum flow rate within the selected pressure difference range of  to
max min

max.
and q is the minimum flow rate within the selected pressure difference range of  to 
min min max.
 
q
min

q = 1 - 100 in % (7)


q

 
Draw a graph as shown in Figure 4 b).
19

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SIST EN 12589:2001
EN 12589:2001 (E)
NOTE Figure 4 also includes an example of how the results in Figure 4 a) are calculated.
5.6 Presentation of results
The results of the tests can conveniently be presented as shown in Figure 4 b). Alternatively, the
same parameters can be presented in tabular form.
6 Tests to determine induced air flow rate
6.1 Principle
To determine the variation of induced air flow rate with primary air flow rate and static pressures
upstream and downstream of the terminal unit. Also, where appropriate, to determine the effect
of change of induction nozzle configuration and, in the case of fan powered terminal units,
change in fan speed. The basis of the test method is to measure primary and total air flow rates
and derive the induced flow rate by differencing the two values.
6.2 Test measurements
The following measurements shall be made during the tests:
a) p inlet duct static gauge pressure in Pa.
s1
b) p outlet duct static gauge pressure in Pa.
s2
c)  air temperature at the primary air inlet to the unit under test in
C.
1

d) air temperature at the discharge of the unit under test in
C.
2
e)  air temperature at the induction port of the unit under test in
C.
3
f)  flow meter pressure difference or the appropriate parameter that relates to
1
primary flow rate q in Pa.


g)  air temperature immediately upstream of the primary air flow meter in
C.
u
h)  flow meter pressure difference or appropriate parameter that relates to total
2
discharge flow rate q in Pa.


i)  air temperature immediately upstream of the total discharge air flow meter in
D

C.
j) n Fan speed control setting for IFS and IFP units.
k) S Induction damper and/or valve setting (for IU units).
6.3 Test installation
A typical test installation for all units is shown in Figure 5; it is based on using an auxiliary fan to
control the outlet duct static pressure p .
s2
The flow rate measuring stations shall conform to ISO 5167-1.
The measurement plane of the outlet duct static pressure measurement shall conform to the
following:
a) The outlet duct shall be of the same cross-section as the unit outlet spigot and a
minimum of 3 equivalent diameters (3d ) in length.
e2
b) The plane of measurement of p shall be located at a minimum distance of 2,5 d
s2 e2
downstream of the unit outlet, or a location where a uniform static pressure distribution exists
20

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SIST EN 12589:2001
EN 12589:2001 (E)
within ± 10 % of the value at the measurement tapping. The criteria which gives the greatest
length downstream of the unit discharge shall be used for p measurement.
s2
c) The transformation shall be at a minimum of 0,5 d downstream of the p
e2 s2
measurement plane.
Performance of static pressure measurement device is described in annex A.
6.4 Test procedure
The parameters applicable for each type of unit to be tested are shown in Table 8.
Table 8  Parameters affecting induced flow rate
Unit type Parameters affecting induced
flow rate
IU  p  p  q   S
s1 s2 v1
IFS      p   q    n
s2 v1
IFP      p   q    n
s2 v1
Set the supply fan running and use the auxiliary fan to control the selected fixed values of outlet
duct static pressure p . Table 9 shows the combinations of parameters at w
...