ISO 21927-3:2006

INTERNATIONAL ISO
STANDARD 21927-3
First edition
2006-11-15

Smoke and heat control systems —
Part 3:
Specification for powered smoke and
heat exhaust ventilators
Systèmes de contrôle de fumée et de chaleur —
Partie 3: Spécifications pour les ventilateurs mécaniques d'évacuation
des fumées et de la chaleur




Reference number
ISO 21927-3:2006(E)
©
ISO 2006

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ISO 21927-3:2006(E)
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ISO 21927-3:2006(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 1
4 Design requirements . 4
4.1 Application classes . 4
4.2 Motor rating . 4
4.3 Motor specification. 4
4.4 Hot-gas fan . 4
5 General testing procedures . 4
6 Performance requirements and classification. 5
6.1 Temperature/time classification. 5
6.2 Flow and pressure . 5
6.3 Outer surface temperature and cooling air temperature of insulated ventilators . 5
6.4 Wind load. 6
6.5 Snow load . 6
6.6 Operation at low temperature. 6
6.7 Reliability . 6
6.8 Performance data of ventilators. 7
7 Marking . 7
8 Evaluation of conformity. 7
8.1 General. 7
8.2 Initial type testing . 7
8.3 Factory production control. 8
Annex A (normative) Type approval schedule for a range of ventilators . 9
Annex B (normative) Type approval schedule for a product range of motors. 16
Annex C (normative) Test method for performance of powered ventilators at high temperature . 17
Annex D (normative) Test method for resistance to temperature of electric motors for use in
powered ventilators. 23
Annex E (normative) Test method for operation under load. 27
Annex F (normative) Direct field of application for powered smoke- and heat-exhaust ventilators. 28
Bibliography . 29

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ISO 21927-3:2006(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 2.
The main task of technical committees is to prepare International Standards. 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 document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 21927-3 was prepared by Technical Committee ISO/TC 21, Equipment for fire protection and fire fighting,
Subcommittee SC 11, Smoke and heat control systems and components.
ISO 21927 consists of the following parts, under the general title Smoke and heat control systems:
⎯ Part 1: Specification for smoke barriers
⎯ Part 2: Specification for natural smoke and heat exhaust ventilators
⎯ Part 3: Specification for powered smoke and heat exhaust ventilators
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ISO 21927-3:2006(E)
Introduction
Smoke- and heat-exhaust ventilation systems create a smoke-free layer above the floor by removing smoke
and thus improve the conditions for the safe escape and/or rescue of people and animals and the protection of
property and permit the fire to be fought while still in its early stages. They also exhaust hot gases released by
a fire in the developing stage.
The use of smoke- and heat-exhaust ventilation systems to create smoke-free areas beneath a buoyant
smoke layer has become widespread. Their value in assisting in the evacuation of people from construction
works, reducing fire damage and financial loss by preventing smoke logging, facilitating fire fighting, reducing
roof temperatures and retarding the lateral spread of fire is firmly established. For these benefits to be
obtained, it is essential that smoke- and heat-exhaust ventilators operate fully and reliably whenever called
upon to do so during their installed life. A heat- and smoke-exhaust ventilation system is a scheme of safety
equipment intended to perform a positive role in a fire emergency.
It is important that components for smoke- and heat-exhaust systems be installed as part of a properly
designed smoke and heat system.
Smoke- and heat-exhaust ventilation systems help to
⎯ keep the escape and access routes free from smoke,
⎯ facilitate fire-fighting operations by creating a smoke-free layer,
⎯ delay and/or prevent flashover and thus full development of the fire,
⎯ protect equipment and furnishings,
⎯ reduce thermal effects on structural components during a fire,
⎯ reduce damage caused by thermal decomposition products and hot gases.
Depending on the design of the system and the ventilator, powered or natural smoke and heat ventilators can
be used in a smoke- and heat-control system. Powered smoke- and heat-exhaust ventilators can be installed
in the roof or upper part of walls of buildings or in a ducted system with the ventilator inside or outside the
smoke reservoir or in a plant room.
It is important that powered smoke- and heat-exhaust ventilation systems operate based on powered
ventilators. The performance of a powered smoke- and heat-exhaust system depends on
⎯ the temperature of the smoke,
⎯ size, number and location of the exhaust openings,
⎯ the wind influence,
⎯ size, geometry and location of the inlet air openings,
⎯ the time of actuation,
⎯ the location and conditions of the system (for example arrangements and dimensions of the building).
Smoke- and heat-exhaust ventilation systems are used in buildings or construction works where the particular
(large) dimensions, shape or configuration make smoke control necessary.
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ISO 21927-3:2006(E)
Typical examples are
⎯ single and multi-storey shopping malls,
⎯ single and multi-storey industrial buildings and warehouses,
⎯ atria and complex buildings,
⎯ enclosed car parks,
⎯ stairways,
⎯ tunnels,
⎯ theatres.
Depending on differing circumstances and the situation of the building or construction works that can affect
their performance, powered or natural smoke- and heat-exhaust ventilation systems can be used.
It is important that powered and natural exhaust ventilators not be used to extract smoke and hot gases from
the same smoke reservoir.
Special conditions apply where gas extinguishing systems (e.g. in accordance with ISO 14520-1) are used.
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INTERNATIONAL STANDARD ISO 21927-3:2006(E)

Smoke and heat control systems —
Part 3:
Specification for powered smoke and heat exhaust ventilators
1 Scope
This part of ISO 21927 specifies requirements and gives methods for testing powered smoke- and
heat-exhaust ventilators that are intended to be installed as part of a powered smoke- and heat-exhaust
ventilation system. It also provides a procedure for approving a range of powered smoke- and heat-exhaust
ventilators and their motors, from a limited number of tests.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 834-1, Fire resistance tests — Elements of building construction — Part 1: General requirements
ISO 5167 (all parts), Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full
ISO 5221, Air distribution and air diffusion — Rules to methods of measuring air flow rate in an air handling
duct
ISO 5801, Industrial fans — Performance testing using standardized airways
ISO 10294-1, Fire resistance tests — Fire dampers for air distribution systems — Part 1: Test method
ISO 13943, Fire safety — Vocabulary
ISO 21927-2:2004, Smoke and heat control systems — Part 2: Specification for natural smoke and heat
exhaust ventilators
IEC 60034-1, Rotating electrical machines — Part 1: Rating and performance
IEC 60034-2, Rotating electrical machines — Part 2: Methods for determining losses and efficiency of rotating
electrical machinery from tests (excluding machines for traction vehicles)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13943 and the following apply.
3.1
smoke- and heat-control system
arrangement of components installed in a construction work to limit the effects of smoke and heat from a fire
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ISO 21927-3:2006(E)
3.2
smoke- and heat-exhaust system
smoke-control system that exhausts smoke and heat from a fire in a construction work or part of a
construction work
3.3
smoke- and heat-exhaust ventilation system
SHEVS
components jointly selected to exhaust smoke and heat to establish a buoyant layer of warm gases above
cooler, cleaner air
3.4
natural ventilation
ventilation caused by buoyancy forces due to differences in density of the gases because of temperature
differences
3.5
powered ventilation
ventilation caused by the positive displacement of gases through a ventilator
NOTE Fans are usually used.
3.6
ventilator
device for enabling the movement of gases into or out of a construction work
3.7
exhaust ventilator
device for the movement of gases out of the construction work
3.8
insulated motor
motor thermally insulated from the environment which generally includes a motor casing
3.9
smoke- and heat-exhaust ventilator
SHEV
device specially designed to move smoke and hot gases out of the construction work under conditions of fire
3.10
dual purpose ventilator
smoke- and heat-exhaust ventilator that has provision to allow its use for comfort (i.e. day-to-day) ventilation
3.11
emergency ventilator
smoke- and heat-exhaust ventilator that is not used for comfort (i. e. day-to-day) ventilation
3.12
automatically initiated powered smoke- and heat-exhaust ventilator
powered smoke- and heat-exhaust ventilator that operates automatically after the outbreak of fire if called
upon to do so
3.13
smoke reservoir
region within a building limited or bordered by smoke curtains or structural elements and which, in the event of
a fire, retains a thermally buoyant smoke layer
3.14
hot-gas fan
fan that is suitable for handling hot gases for a specified time/temperature profile
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ISO 21927-3:2006(E)
3.15
powered smoke- and heat-exhaust ventilator
hot-gas fan that is suitable for handling hot gases for a limited period only
3.16
powered roof ventilator
partition fan designed for mounting on a roof and having exterior weather protection
3.17
insulated ventilator
ventilator insulated to limit the external surface temperature to reduce the danger of injury to persons or
damage to materials
3.18
smoke-reservoir ventilator
ventilator suitable for operation fully immersed in a smoke reservoir
3.19
non-smoke-reservoir ventilator
ventilator not suitable for operation fully immersed in a smoke reservoir
3.20
powered ventilator product range
physically similar ventilators using the same form of construction and materials throughout, with the same
methods of impeller construction and motor mounting and construction, and electrical connection in which the
following can vary across the range:
⎯ overall dimensions of the units;
⎯ impeller diameter and width, hub size, blade length and number of blades of the impeller;
⎯ size of the motor
3.21
powered ventilator motor range
motors that are physically similar, using the same form of construction, i.e. same materials and manufacturing
method for carcase, cooling impeller, when fitted, and end covers; same insulation specification that includes
sheet insulation used for coil separation and slot insulation, winding-impregnation material (varnish or resin,
etc.), lead insulation, terminal blocks and any other materials that can affect the integrity of the insulation;
same bearing type, class of fit, lubricant and arrangement, with motor windings based on the same maximum
winding temperature and class of insulation, in which the following can vary across the range:
⎯ frame size;
⎯ rotational speed;
⎯ electrical windings, including multi-speed;
⎯ form of mounting, e.g. foot, flange, pad, clamp, etc.
3.22
motor rating
maximum power that the motor delivers continuously without exceeding the allowable temperature rise
3.23
fire position
position of a component to be reached and maintained while venting smoke and heat
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ISO 21927-3:2006(E)
4 Design requirements
4.1 Application classes
A powered ventilator shall be classified into one or more of the following application classes:
⎯ insulated or uninsulated;
⎯ smoke reservoir or non-smoke reservoir;
⎯ dual purpose or emergency only use;
⎯ ducted cooling air required.
4.2 Motor rating
4.2.1 The motors shall be selected for continuous operation at the power required for normal ambient
temperature, not just for operation at high temperature.
4.2.2 Motor ratings shall be limited either by the temperature rise for one class lower than the insulation
class of the motor, as defined in IEC 60034-1 and as given in Table 1 of this part of ISO 21927, or for motors
with class B or class F insulation to the motor rated output power being 15 % above the absorbed power at a
3
density of 1,2 kg/m .
Table 1 — Motor temperature ratings
Motor insulation Temperature rise at ambient
Class H or C Class F
Class F Class B
Class B Class E
4.3 Motor specification
Motors shall comply with the requirements of IEC 60034-1.
4.4 Hot-gas fan
The time/temperature profile that a hot-gas fan is required to operate under, can be “continuous” or more
specific to the application. Special materials may be incorporated in the fan that can have a direct or indirect
drive. The motor may be in the air-stream on a direct-drive fan or separated from it by a bifurcation tunnel.
Indirect drive fans may incorporate a means of cooling belts, bearings or other drive components.
5 General testing procedures
For type approval, tests shall be carried out in accordance with Annexes A, B, C, D and E. For each test, a
test report shall be prepared in accordance with Annexes C and/or D.
For different directions of the motor axis, a separate test shall be done for either direction (horizontal and/or
vertical).
NOTE A direct field of application for the direction of the motor axis (horizontal and/or vertical) is under consideration
as of the date of publication of this part of ISO 21927.
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ISO 21927-3:2006(E)
6 Performance requirements and classification
6.1 Temperature/time classification
6.1.1 A ventilator shall be classified (see Table 2) as
a) F200;
b) F300;
c) F400;
d) F600;
e) F842;
f) Not classified.
6.1.2 For products intended to be installed within a building, there shall be no significant leakage of smoke
from the furnace coming from the housing of the ventilator during the entire test period.
6.1.3 At the appropriate temperature given in Table 2, a ventilator shall function for not less than the
appropriate minimum time and shall re-start when tested in accordance with Annex C.
Table 2 — Test temperature and functioning time according to classification
Class Temperature Minimum functioning period
°C minutes
F200 200 120
F300 300 60
F400 400 120
F600 600 60
F842 842 30
Not classified as specified as specified
by sponsor by sponsor
6.2 Flow and pressure
When tested in accordance with Annex C, at the appropriate temperature and for the appropriate time given in
Table 2, the volume flow shall not change by more than 10 % or the static pressure shall not change by more
than 20 % of that measured at the end of the warm-up period of the test.
6.3 Outer surface temperature and cooling air temperature of insulated ventilators
When the ventilator is tested in accordance with Annex C, at the temperature and for the time appropriate to
the product temperature/time category:
⎯ the outer surface temperature of an insulated ventilator shall not increase by more than 180 °C in
accordance with ISO 834-1 for any individual value;
⎯ the cooling air expelled from the unit shall not exhibit an increase of temperature of more than 180 °C
from the initial room temperature.
NOTE Increases above the specified temperature can increase the fire risk.
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ISO 21927-3:2006(E)
6.4 Wind load
If the ventilator is designed to be installed at the atmospheric termination of a system and is fitted with flaps or
louvres and these project above the wind deflectors (cowl or wind shield), the flaps or louvres shall open in
less than 30 s against of a load of 200 Pa, when the ventilator is tested in accordance with Annex E.
6.5 Snow load
6.5.1 If the ventilator is designed to be installed at the atmospheric termination of a system, the ventilator
shall be classified as one of the following:
⎯ SL 0;
⎯ SL 125;
⎯ SL 250;
⎯ SL 500;
⎯ SL 1 000;
⎯ SL A.
The designations 0, 125, 250, 500, 1 000 and “A” represent the test snow load, expressed in pascal, applied
when the ventilator is tested in accordance with Annex E. The “A” in “SL A” will be replaced by the test snow
load when this exceeds 1 000, or by the test load if one of the four defined values is not used.
Where the minimum angle of installation (combining roof pitch and ventilator pitch) recommended by the
supplier exceeds 45°, the ventilator takes the classification SL 1 000 without a test; except where the snow is
prevented from slipping from the ventilator, e.g. by wind deflectors.
If the ventilator is fitted with deflectors, the snow-load classification, SL, shall not be less than 2 000d, where d
is the depth of snow, in metres, that can be contained with the confines of the deflectors.
6.5.2 The ventilator shall open to its fire-open position in not more than 30 s after actuation when tested
under the snow load appropriate to its classification in accordance with Annex E.
The following types of ventilators can be suitable for use on heated buildings without a snow-load
classification test:
a) vertical discharge units without flaps or dampers;
b) vertical discharge units with uninsulated metal flaps or dampers.
6.6 Operation at low temperature
A powered ventilator with a separate device for the operation of the dampers, flaps or louvres that does not
use the air pressure from the fan shall conform to ISO 21927-2:2004, 8.3, when tested in accordance with
ISO 21927-2:2004, Annex E.
6.7 Reliability
A powered ventilator with dampers, flaps or louvres or a separate device for the operation of the dampers,
flaps or louvres that does not use the air pressure from the fan shall conform to ISO 21927-2:2004, 8.1, when
tested in accordance with ISO 21927-2:2004, Annex C.
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ISO 21927-3:2006(E)
6.8 Performance data of ventilators
6.8.1 The supplier shall provide a data sheet giving the aerodynamic and acoustic performance data of the
ventilator assessed at ambient temperature in accordance with ISO 5801, taking into account the reduction in
performance caused by the increased clearances required for high temperature.
It is permissible to convert these figures to determine the performance with hot gases and at other speeds of
rotation using the scaling equations from ISO 5801, with due allowance for tip clearance effects.
6.8.2 If a ventilator is designed to be fitted with a duct for cooling air, the data sheet shall include the
volume pressure characteristic of the auxiliary system and the minimum cooling air flow required.
7 Marking
The ventilator shall be marked with the following:
a) name or trade mark of the supplier;
b) type and model;
c) application classes;
d) temperature/time category;
e) maximum exhaust temperature in °C;
f) functioning period in minutes;
g) year of manufacture;
h) technical data such as power, current, voltage, pressure, volume flow;
i) motor insulation class;
j) snow load class;
k) number and the year of this part of ISO 21927.
8 Evaluation of conformity
8.1 General
The compliance of powered smoke- and heat-exhaust ventilators with the requirements of this part of
ISO 21927 shall be demonstrated by
⎯ initial type testing,
⎯ factory production control by the manufacturer.
8.2 Initial type testing
Initial type testing shall be performed on first application of this part of ISO 21927. Tests previously performed
in accordance with the provisions of this part of ISO 21927 (e.g. same product, same characteristic(s), test
method, sampling procedure, system of evaluation of conformity) may be taken into account. In addition, initial
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ISO 21927-3:2006(E)
type testing shall be performed at the beginning of the production of a new product type or at the beginning of
a new method of production (where these can affect the stated properties).
All characteristics given in Clause 5 and 6.1 to 6.7 shall be subject to initial type testing.
Annex F gives rules of possible changes to the originally classified product without the need of re-testing.
8.3 Factory production control
The manufacturer shall establish, document and maintain a factory production control (FPC) system to ensure
that the products placed on the market conform with the stated performance characteristics. The FPC system
shall consist of procedures, regular inspections and tests and/or assessments and the use of the results to
control raw and other incoming materials or components, equipment, the production process and the product,
and shall be sufficiently detailed to ensure that the conformity of the product is apparent.
An FPC system conforming with the requirements of the relevant part(s) of ISO 9001, and made specific to
the requirements of this part of ISO 21927, shall be considered to satisfy the above requirements.
The results of inspections, tests or assessments requiring action shall be recorded, as shall any action taken.
The action to be taken when control values or criteria are not met shall be recorded.
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ISO 21927-3:2006(E)
Annex A
(normative)

Type approval schedule for a range of ventilators
A.1 Reduction of numbers of tests for ventilators forming a product range
For the purpose of type approval, it is not usually considered necessary to test every size of ventilator in a
product range, provided that the following are tested and the range complies with the rules given in
Clauses A.3 and A.4 and Annex B:
a) ventilator with the most highly stressed impeller or the ventilators with impellers in which the individual
stress in any material weld or fastening is the highest as appropriate (see Clause A.4);
b) for ventilators with motors mounted in an enclosure that restricts the cooling, the worst case shall be
tested, for example the ventilator with the highest ratio of motor cross-sectional area to cross-sectional
area through which the cooling air flows;
c) at least two sizes are tested at their highest rotational speed;
d) ventilator with the smallest motor-frame size to be used;
e) if the highest impeller stress levels are determined by geometric similarity conditions from A.4.1, a
sufficient number of sizes of ventilators to ensure that the impeller diameters of the range are from 0,8 to
1,26 of those tested;
f) if the highest impeller stress levels are determined by the calculation methods in A.4.2
...