ISO/TR 5925-2:2006

TECHNICAL ISO/TR
REPORT 5925-2
Second edition
2006-07-15
Fire tests — Smoke-control door
and shutter assemblies —
Part 2:
Commentary on test method and the
applicability of test conditions and the
use of test data in a smoke containment
strategy
Essais au feu — Assemblages porte et volet pare-fumée —
Partie 2: Commentaires sur la méthode d'essai et applicabilité des
conditions d'essai et emploi des données d'essai dans une stratégie de
confinement de la fumée
Reference number
©
ISO 2006
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ii © ISO 2006 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Terms and definitions. 1
3 General principles. 2
4 Smoke control. 3
5 Appropriateness of the test conditions and the selection of sealing system. 10
6 Use of test outputs . 11
Bibliography . 12

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
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In exceptional circumstances, when a technical committee has collected data of a different kind from that
which is normally published as an International Standard (“state of the art”, for example), it may decide by a
simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely
informative in nature and does not have to be reviewed until the data it provides are considered to be no
longer valid or useful.
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/TR 5925-2 was prepared by Technical Committee ISO/TC 92, Fire safety, Subcommittee SC 2, Fire
containment.
This second edition cancels and replaces the first edition (ISO/TR 5925-2:1997), which has been technically
revised.
ISO/TR 5925 consists of the following parts, under the general title Fire tests — Smoke-control door and
shutter assemblies:
1)
⎯ Part 1 : Ambient and medium temperature leakage test procedure
⎯ Part 2: Commentary on test method and the applicability of test conditions and the use of test data in a
smoke containment strategy
1) To be published. (Revision of ISO 5925-1:1981)
iv © ISO 2006 – All rights reserved

Introduction
Technical Committee ISO/TC92, Fire Safety, has prepared ISO 5925-1, a test specification for smoke control
doors.
In a fire, the decomposition of materials results in the production of heat and fire gases containing smoke
particles. The associated expansion of gases can lead to the creation of a pressure differential across door
faces often influenced by wind pressures, mechanical or natural smoke extract systems, stack effect or a
combination of these. This pressure differential induces the movement of smoke or air past any openings or
gaps, including those in a door assembly. Schemes to keep areas within buildings free of smoke use various
techniques, including barriers to its movement, exhausting, dilution, pressurization, either singly or in some
suitable combination of all of these. Where the pressure differential across the door is positive, i.e. gases are
being driven through any gap; standard tests have been developed to measure the leakage of smoke when
such conditions exist. The test method does not deal generally with doors installed in conjunction with active
smoke control methods, such as pressurization or exhaust, and this part of ISO/TR 5925 has been prepared
to assist designers to specify doors that have the appropriate smoke control characteristics for the situation in
which they are being used.
In addition to identifying when the door is likely to have a passive smoke control function, this part of
ISO/TR 5925 tries to make it clear as to when ambient or medium temperature smoke control is appropriate,
and when the threshold gap is significant.
TECHNICAL REPORT ISO/TR 5925-2:2006(E)

Fire tests — Smoke-control door and shutter assemblies —
Part 2:
Commentary on test method and the applicability of test
conditions and the use of test data in a smoke containment
strategy
1 Scope
This Technical Report provides a commentary that explains the general philosophy and factors on which the
test specified in Part 1 of ISO 5925 has been designed, to describe the limitations of its application and to
provide some general guidance for those who use the result of the test. Smoke control-door and shutter
assemblies can be used as part of a smoke containment strategy for the purposes of life safety or property
protection.
2 Terms and definitions
For the purposes of this document, the terms and definitions given in Part 1 of ISO 5925 and the following
apply.
2.1
door assembly
assembly comprising a fixed part (the door frame), one or more movable parts (the door leaves) and its
hardware
NOTE The purpose of the door assembly is to allow or prevent access of persons and/or goods. The term hardware
includes such items as hinges, latches, door handles, locks, keyholes (excluding keys), letter plates, sliding gear, closing
devices, electrical wiring and any other items that can influence the performance of the assembly being tested.
2.2
shutter assembly
assembly comprising fixed parts, e.g. a barrel housing and vertical guides and one or more moveable parts,
normally in the form of a curtain constructed from linked metal laths, or other flexible material and a barrel on
which the curtain is wound together with any powered mechanism, e.g. an electric motor and its associate
power supply
NOTE The shutter assembly is to allow the passage of goods, vehicles or persons, albeit where the shutter is
normally closed in use, a personnel door should be provided for the passage of persons.
2.3
fire door
door or shutter assembly capable of maintaining for a specified period some, or all of the fire resistance
criteria defined in ISO 3008, as appropriate for the door in use
2.4
smoke control door
door or shutter assembly whose primary function is to restrict the passage of smoke as determined by a test in
accordance with Part 1 of ISO 5925
2.5
fire and smoke control door
door or shutter assembly meeting some, or all of the criteria for fire and smoke control as appropriate for the
door in use
2.6
ambient temperature
for the purpose of this Technical Report, ambient temperature is an air temperature of (20 ± 10) °C
2.7
medium temperature
for the purpose of this Technical Report, medium temperature is an air temperature of (200 ± 20) °C
2.8
high temperature
temperature representative of a standardized fully developed fire which is as specified in ISO 834-1
NOTE For ease of use, doors are identified by a code letter/number and these are shown in Figure 1.
2.9
make-up air
air that is made available to dilute the fire gases in order to reduce their temperature
3 General principles
3.1 Smoke and its influence
Smoke is the term used to describe the airborne products of combustion generated by the fire, together with
large volumes of air that become entrained into them due to their motion. These combustion products can
contain solid and liquid particulates within a gaseous mass.
Almost all fires produce smoke, which, when enclosed by a building, has the potential to become extremely
hazardous to its occupants and damaging to property. Most deaths in fires are due to smoke inhalation, rather
than to the victim having been burned.
The gaseous combustion products, chiefly carbon dioxide and water vapour, usually include toxic gases, the
most common being carbon monoxide, although hydrogen cyanide and other minor species can be present to
some extent. Amongst these, irritant gases such as acrolein can have a significant effect on people attempting
to escape fire.
The solid and liquid fractions of the products of combustion are also responsible for the poor visibility through
smoke. This adds to the problems presented by the smoke. Not only is it physiologically hazardous in its own
right, but escape through it is made more difficult by it obscuring escape routes. These fractions can
themselves be irritants and can be particularly dangerous to people who are subject to asthma or other
respiratory problems.
Smoke can also cause damage to property. Most fires produce soot and many generate corrosive gases such
as hydrogen chloride. The effect of these on sensitive equipment can be responsible for large monetary
losses due to equipment damage, the need for system clean-up and subsequent business interruption.
3.2 Smoke dynamics
All fires start from an ignition and grow at a rate generally determined by the environment in which the fire
starts and the nature of the materials involved in the event. Sometimes the fire can smoulder for a
considerable period, especially if the materials that have been ignited have a low rate of heat release or the
environment does not readily sustain combustion. Smoke produced during such a fire has very little buoyancy
and whatever buoyancy it has due to gas density differentials as a result of increased temperature is soon lost.
2 © ISO 2006 – All rights reserved

Smoke produced under these low temperature conditions is, therefore, subject to the movement dominated by
the ambient air current, particularly any that is induced by mechanical means, such as ventilation and air
conditioning. In the absence of ambient currents, these cool gases generally mix with the environment and do
not stratify as is expected from hot buoyant gases.
Once the heat release increases, the smoke’s buoyancy increases and it soon begins to dominate air currents
in the enclosure. When the fire reaches a sufficient size, the smoke rises in a plume towards the ceiling. As it
does so, it entrains large volumes of air, greatly increasing smoke volume but reducing its temperature and
the concentration of chemical constituents.
The total entrained volume of air increases substantially with increasing height of the plume. With sufficient
buoyancy, the smoke impinges the ceiling, spreading out radially to reach any side walls and then forms a
layer that deepens as more smoke is produced.
Smoke flows out of the enclosure of origin through any upper openings that exist or develop. This outflow is
balanced by an inflow of air usually at a lower level. The openings can exist by design or occur as a result of
failure of one of the boundary elements.
An opening can be part of a smoke ventilation or extract system, where either vents open to allow smoke out
or a fan-assisted ducting system exhausts the hot gases and smoke. In such cases, make-up air is required to
come into the enclosure at a lower level, normally from designated sources, but also, possibly, from ar
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