ISO 21927-7:2017

INTERNATIONAL ISO
STANDARD 21927-7
First edition
2017-04
Smoke and heat control systems —
Part 7:
Smoke ducts sections
Systèmes pour le contrôle des fumées et de la chaleur —
Partie 7: Sections des conduits de désenfumage
Reference number
©
ISO 2017
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Smoke control duct section requirements . 3
4.1 General . 3
4.1.1 Fire resistance — multi-compartment smoke control duct section . 3
4.1.2 Fire resistance — single compartment smoke control duct section . 4
4.2 Construction and components: Characteristics . 4
4.2.1 Construction and operation . 4
4.2.2 Structural supports used for smoke control duct sections . 4
4.2.3 Duct sealant materials used in or between smoke control duct sections . 4
4.2.4 Penetration seals between fire compartments . 4
4.2.5 Other components . 5
4.3 Fire resistance performance criteria: Multi-compartment fire resisting smoke
control duct sections . 5
4.3.1 Integrity, insulation, leakage . 5
4.3.2 Fire resistance classification and designation. 6
4.4 Fire resistance performance criteria: Single compartment smoke control duct sections . 6
4.4.1 Integrity, leakage . 6
4.4.2 Fire resistance classification and designation. 6
5 Test methods . 7
5.1 Ambient leakage tests . 7
5.2 Fire resistance tests . 7
5.2.1 General. 7
5.2.2 Smoke control duct section: integrity and insulation . 7
5.2.3 Leakage rated smoke control duct section . 8
6 Marking and documentation . 8
7 Product, installation and maintenance information (documentation) .8
7.1 Product specification . 8
7.2 Installation information . 8
7.3 Maintenance information . 9
Annex A (informative) Example of inspection and maintenance procedure .10
Bibliography .11
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.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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on the ISO list of patent declarations received (see www .iso .org/ patents).
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URL: w w w . i s o .org/ iso/ foreword .html.
This document 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.
A list of all parts in the ISO 21927 series can be found on the ISO website.
iv © ISO 2017 – All rights reserved

Introduction
This document contains the basic performance and requirements for smoke control duct sections,
which are to be used in conjunction with pressure differential systems and smoke and heat control
systems. They may also be used to pressurize when gas extinguishing systems are used.
Particular reference is made to EN 1366-8 and EN 1366-9, which define the fire resistance testing
associated with these products and EN 13501-4, which provides details on their fire resistance
classification.
In addition to the prevention of transmission of smoke and combustion products from a fire zone,
smoke control duct sections are utilized to contain the spillage of otherwise harmful and toxic
extinguishing gases from the affected area, and for the control of pressurizing and excess air relief
within pressurization systems.
Smoke control systems are designed to fulfil three basic functions.
a) The extraction of smoke from a single fire compartment to the outside of the building.
b) The extraction of smoke from fire compartments of a building, using a SHEVS connected to one or
more fire compartments. The smoke control duct may or may not pass through other compartments
of the building to reach the outside of the building.
c) The use of pressurization to maintain smoke free clear areas.
Smoke control ducts are commonly used in smoke and heat control systems. They may serve single
compartments or a number of different fire compartments. The systems may be dedicated smoke
extraction or possibly a combined environmental ventilation/smoke extraction.
The smoke and heat control system may remove smoke using either high temperature fans (in
accordance with ISO 21927-3) or natural ventilators (in accordance with ISO 21927-2).
Key
1 fire compartment
2 smoke reservoir
3 air inlet
4 smoke barrier
5 powered smoke and heat exhaust ventilator (fan)
6 smoke control dampers for single compartments
7 smoke control duct sections for single compartments
8 smoke control duct sections for multi compartments
9 smoke control dampers for multi compartments mounted inside or outside of wall or floor
10 smoke control dampers for multi compartments mounted on the surface of the duct
11 electrical equipment
Figure 1 — Example of powered smoke and heat exhaust ventilation
Further guidance on the application of smoke control ducts may be found within the rest of the
EN 12101 series and technical reports.
The areas for which products supplied to this document are considered applicable include, for example,
a) commercial premises,
b) shopping and retail centres,
c) hospitals, and
d) multi-residential buildings.
Smoke control duct sections are intended for use in the following types of systems, including
1) pressurization,
2) pressure relief,
3) extraction systems,
4) ductwork systems, and
vi © ISO 2017 – All rights reserved

5) inerting fire suppression systems.
It is realized that all the above systems do not address smoke directly, but similar properties are
required of such smoke control ducts to limit leakage in a fire and smoke control situation.
INTERNATIONAL STANDARD ISO 21927-7:2017(E)
Smoke and heat control systems —
Part 7:
Smoke ducts sections
1 Scope
This document applies to smoke control duct sections placed on the market and intended to operate
as part of a pressure differential system or smoke and heat exhaust system. This document specifies
requirements and gives reference to the test methods defined for smoke control duct sections and their
associated components (for example, hangers and other items proven at the time of testing), which
are intended to be installed in such systems in buildings. Furthermore, marking and information on
installation and maintenance of these products are also given in this document.
NOTE To avoid duplication, reference is made to a variety of other standards. To this end, this document can
be read in conjunction with EN 1366-8, EN 1366-9 and ISO 6944-1, for details of the fire resistance testing and
EN 13501-4 for corresponding classification.
This document has not considered in detail the detrimental and/or corrosive effects that may be caused
by process chemicals present in the atmosphere, which are drawn through the system intentionally or
inadvertently.
This document also governs associated components used together with smoke control duct sections
such as turning vanes and silencers, with the exception of natural and powered smoke ventilators and
smoke control dampers, which are covered by separate standards.
Ducts for use other than in smoke and heat exhaust/control systems are not covered by this document.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 13943, Fire safety — Vocabulary
EN 1366-8, Fire resistance tests for service installations — Part 8: Smoke extraction ducts
EN 1366-9, Fire resistance tests for service installations — Part 9: Single compartment smoke
extraction ducts
EN 13501-4, Fire classification of construction products and building elements — Part 4: Classification
using data from fire resistance tests on components of smoke control systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13943 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
air inlet
device connected to outside air to allow the entry of air from outside the construction works
3.2
elevated temperature
temperatures in excess of normal ambient air, below those necessary for fire resistance testing, to
which smoke and heat exhaust ducts for single compartments are tested
3.3
fire compartment
enclosed space comprising one or more separate spaces, bounded by elements of construction having
a specified fire resistance and intended to prevent the spread of fire (in either direction) for a given
period of time
3.4
natural smoke and heat control system
smoke and heat ventilation system which uses natural ventilation
Note 1 to entry: Natural ventilation is caused by buoyancy forces due to differences in density of the gases
because of temperature differences.
3.5
penetration seal
product used between the smoke control duct and the fire compartment boundary structure to maintain
the fire resistance, when tested and having met the requirements of EN 1366-8, at the position where a
smoke control duct passes through the element
3.6
powered smoke and heat exhaust system
smoke and heat ventilation system which utilizes a number of hot gas fans that are suitable for handling
hot gases for a limited period of time which causes the positive displacement of gases
3.7
pressure differential systems
system of fans, ducts, vents and other features provided for the purposes of creating a lower pressure
in the fire zone than in the protected space
3.8
smoke and heat exhaust ventilation system
SHEVS
system consisting of products and/or components jointly selected to exhaust smoke and heat
Note 1 to entry: The products and/or components form a system in order to establish a buoyant layer of warm
gases above cooler cleaner air.
3.9
smoke and heat exhaust ventilator
SHEV
device specially designed to move smoke and hot gases out of a construction works under conditions of
fire
3.10
smoke barrier
obstruction to restrict the spread of smoke and hot gases from a fire, forming part of the boundary of a
smoke reservoir or used as a channelling screen, or used as a void edge boundary
3.11
smoke control damper
device automatically or manually activated, which may be open or closed in its operational position, to
control the flow of smoke and hot gases into, from or within a duct
2 © ISO 2017 – All rights reserved

3.12
smoke control duct
smoke control duct which passes horizontally through vertical walls
3.13
smoke control duct
fire resisting smoke control ducts built from more than one smoke
control duct section for use in multi-compartment applications designed to transport smoke and/or hot
gases away from the source of a fire
Note 1 to entry: May also have a dual function as a normal air conditioning duct.
3.14
smoke control duct
smoke control ducts built from more than one smoke control duct section for
use within single fire compartment application designed to transport smoke and/or hot gases away
from the source of a fire
Note 1 to entry: May also have a dual function as a normal air conditio
...