ISO 6944-1:2024

Fire containment — Elements of building construction — Part 1: Ventilation ducts

This document specifies a method for determining the fire resistance of vertical and horizontal ventilation ducts under standardized fire conditions. The test examines the behaviour of ducts exposed to fire from the outside (duct A) and fire inside the duct (duct B). This document is intended to be used in conjunction with ISO 834-1. This document is not applicable to: a) ducts whose fire resistance depends on the fire resistance performance of a ceiling; b) ducts containing fire dampers at points where they pass through fire separations; c) doors of inspection openings, unless included in the duct to be tested; d) two-sided or three-sided ducts; e) the fixing of suspension devices to floors or walls; f) kitchen extract ducts (see ISO 6944-2). NOTE Annex A provides general guidance and gives background information.

Endiguement du feu — Éléments de construction — Partie 1: Conduits de ventilation

General Information

• Status: Published
• Publication Date: 25-Jun-2024
• ICS: 13.220.50 - Fire-resistance of building materials and elements
• ICS: 91.140.30 - Ventilation and air-conditioning systems
• Technical Committee: ISO/TC 92/SC 2 - Fire containment
• Drafting Committee: ISO/TC 92/SC 2/WG 4 - Ventilation ducts and fire dampers
• Current Stage: 6060 - International Standard published
• Start Date: 26-Jun-2024
• Due Date: 02-May-2025
• Completion Date: 26-Jun-2024

Relations

• Revises: ISO 6944-1:2008 - Fire containment — Elements of building construction — Part 1: Ventilation ducts
• Effective Date: 04-Nov-2023
• Revises: ISO 6944-1:2008/Amd 1:2015 - Fire containment — Elements of building construction — Part 1: Ventilation ducts — Amendment 1
• Effective Date: 04-Nov-2023

Standards Content (Sample)

International
Standard
ISO 6944-1
Second edition
Fire containment — Elements of
2024-06
building construction —
Part 1:
Ventilation ducts
Endiguement du feu — Éléments de construction —
Partie 1: Conduits de ventilation
Reference number
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Apparatus . 2
5 Test conditions .10
6 Test specimen .11
6.1 Size .11
6.1.1 General .11
6.1.2 Length .11
6.1.3 Cross-section .11
6.2 Number .11
6.3 Design .11
6.3.1 General .11
6.3.2 Minimum separation .11
6.3.3 Configuration of duct A (horizontal only) . 12
6.3.4 Openings in duct B . 12
6.3.5 Joints in horizontal ducts . 12
6.3.6 Joints in vertical ducts . 13
6.3.7 Support for vertical ducts. 13
6.3.8 Compensators .14
7 Installation of test specimen . . 14
7.1 General .14
7.2 Standard supporting construction . 15
7.3 Non-standard supporting constructions . 15
7.4 Restraint of ducts .16
7.4.1 Inside the furnace .16
7.4.2 At the penetration point .16
7.4.3 Outside the furnace . .16
7.4.4 Closure . .16
7.4.5 Fire stopping .16
7.4.6 Unsupported vertical ducts .16
8 Conditioning .16
8.1 General .16
8.2 Hygroscopic sealing materials .16
9 Application of instrumentation . 17
9.1 Thermocouples .17
9.1.1 Furnace thermocouples (plate thermometers) .17
9.1.2 Unexposed surface thermocouples .19
9.2 Pressure . 22
10 Test procedure .23
10.1 General . 23
10.2 Control of conditions to permit assessment of integrity . 23
10.2.1 Duct A . 23
10.2.2 Duct B . 23
10.3 Test measurements and observations . 23
10.3.1 Integrity . 23
10.3.2 Insulation .24
10.3.3 Restraint forces and thermal elongation or shortening .24
10.3.4 Additional observations.24

iii
10.4 Termination of the test .24
11 Performance criteria .24
11.1 Integrity .24
11.2 Insulation .24
11.2.1 General .24
11.2.2 Ducts with internal combustible linings only .24
11.3 Smoke leakage . 25
11.4 Determination of fire resistance . 25
12 Test report .25
13 Field of direct application of test results .25
13.1 General . 25
13.2 Vertical and horizontal ducts . 25
13.3 Sizes of ducts . 26
13.4 Pressure difference . 26
13.5 Height of vertical ducts . 26
13.5.1 Ducts supported at each storey .
...

FINAL DRAFT
International
Standard
ISO/FDIS 6944-1
ISO/TC 92/SC 2
Fire containment — Elements of
Secretariat: ANSI
building construction —
Voting begins on:
2024-03-28
Part 1:
Ventilation ducts
Voting terminates on:
2024-05-23
Endiguement du feu — Éléments de construction —
Partie 1: Conduits de ventilation
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 6944-1:2024(en) © ISO 2024

FINAL DRAFT
ISO/FDIS 6944-1:2024(en)
International
Standard
ISO/FDIS 6944-1
ISO/TC 92/SC 2
Fire containment — Elements of
Secretariat: ANSI
building construction —
Voting begins on:
Part 1:
Ventilation ducts
Voting terminates on:
Endiguement du feu — Éléments de construction —
Partie 1: Conduits de ventilation
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2024
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 6944-1:2024(en) © ISO 2024

ii
ISO/FDIS 6944-1:2024(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Apparatus . 2
5 Test conditions .10
6 Test specimen .11
6.1 Size .11
6.1.1 General .11
6.1.2 Length .11
6.1.3 Cross-section .11
6.2 Number .11
6.3 Design .11
6.3.1 General .11
6.3.2 Minimum separation .11
6.3.3 Configuration of duct A (horizontal only) . 12
6.3.4 Openings in duct B . 12
6.3.5 Joints in horizontal ducts . 12
6.3.6 Joints in vertical ducts . 13
6.3.7 Support for vertical ducts. 13
6.3.8 Compensators .14
7 Installation of test specimen . . 14
7.1 General .14
7.2 Standard supporting construction . 15
7.3 Non-standard supporting constructions . 15
7.4 Restraint of ducts .16
7.4.1 Inside the furnace .16
7.4.2 At the penetration point .16
7.4.3 Outside the furnace . .16
7.4.4 Closure . .16
7.4.5 Fire stopping .16
7.4.6 Unsupported vertical ducts .16
8 Conditioning .16
8.1 General .16
8.2 Hygroscopic sealing materials .16
9 Application of instrumentation . 17
9.1 Thermocouples .17
9.1.1 Furnace thermocouples (plate thermometers) .17
9.1.2 Unexposed surface thermocouples .19
9.2 Pressure . 22
10 Test procedure .23
10.1 General . 23
10.2 Control of conditions to permit assessment of integrity . 23
10.2.1 Duct A . 23
10.2.2 Duct B . 23
10.3 Test measurements and observations . 23
10.3.1 Integrity . 23
10.3.2 Insulation .24
10.3.3 Restraint forces and thermal elongation or shortening .24
10.3.4 Additional observations.24

iii
ISO/FDIS 6944-1:2024(en)
10.4 Termination of the test .24
11 Performance criteria .24
11.1 Integrity .24
11.2 Insulation .24
11.2.1 General .24
11.2.2 Ducts with internal combustible linings only .24
11.3 Smoke leakage . 25
11.4 Determination of fire resistance . 25
12 Test report .
...

INTERNATIONAL ISO
STANDARD 6944-1
First edition
2008-04-15
Fire containment — Elements of building
construction —
Part 1:
Ventilation ducts
Endiguement du feu — Éléments de construction —
Partie 1: Conduits de ventilation

Reference number
Title:
From AutoCAD Drawing "Logo0002"
Creator:
TeXMathEditor participial utilities
Preview:
This EPS picture w as not saved
with a preview included in it.
©
ISO 2008
Comment:
This EPS picture will print to a
PostScript printer, but not to
other types of printers.
ISO/FDIS 6944-1
ISO/TC 92/SC 2
Secretariat: ANSI
Date: 2024-03-14
Fire containment — Elements of building construction —
Part 1:
Ventilation ducts
Endiguement du feu — Éléments de construction —
Partie 1: Conduits de ventilation
FDIS stage
Reference number
Title:
From AutoCAD Drawing "Logo0002"
Creator:
TeXMathEditor participial utilities
Preview:
This EPS picture w as not saved
with a preview included in it.
©
ISO 2008
Comment:
This EPS picture will print to a
PostScript printer, but not to
other types of printers.
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this
publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical,
including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can
be requested from either ISO at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
E-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
iii
Contents Page
Foreword . vii
Introduction . ix
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Apparatus . 2
5 Test conditions . 20
6 Test specimen . 20
6.1 Size . 20
6.1.1 General . 20
6.1.2 Length . 20
6.1.3 Cross-section . 20
6.2 Number . 20
6.3 Design . 21
6.3.1 General . 21
6.3.2 Minimum separation . 21
6.3.3 Configuration of duct A (horizontal only) . 21
6.3.4 Openings in duct B . 21
6.3.5 Joints in horizontal ducts . 21
6.3.6 Joints in vertical ducts . 23
6.3.7 Support for vertical ducts. 24
6.3.8 Compensators . 24
7 Installation of test specimen . 24
7.1 General . 24
7.2 Standard supporting construction . 25
7.3 Non-standard supporting constructions . 26
7.4 Restraint of ducts. 27
7.4.1 Inside the furnace . 27
7.4.2 At the penetration point . 27
7.4.3 Outside the furnace . 27
7.4.4 Closure . 27
7.4.5 Fire stopping . 27
7.4.6 Unsupported vertical ducts . 27
8 Conditioning . 27
8.1 General . 27

iv
8.2 Hygroscopic sealing materials . 27
9 Application of instrumentation . 28
9.1 Thermocouples . 28
9.1.1 Furnace thermocouples (plate thermometers) . 28
9.1.2 Unexposed surface thermocouples . 32
9.2 Pressure . 38
10 Test procedure . 38
10.1 General . 38
10.2 Control of conditions to permit assessment of integrity . 38
10.2.1 Duct A . 38
10.2.2 Duct B . 38
10.3 Test measurements and observations . 39
10.3.1 Integrity . 39
10.3.2 Insulation . 39
10.3.3 Restraint forces and thermal elongation or shortening . 39
10.3.4 Additional observations . 40
10.4 Termination of the test . 40
11 Performance criteria . 40
11.1 Integrity . 40
11.2 Insulation . 40
11.2.1 General . 40
11.2.2 Ducts with internal combustible linings only . 40
11.3 Smoke leakage . 41
11.4 Determination of fire resistance . 41
12 Test report . 41
13 Field of direct application of test results . 41
13.1 General . 41
13.2 Vertical and horizontal ducts. 41
13.3 Sizes of ducts . 42
13.4 Pressure difference . 42
13.5 Height of vertical ducts . 42
13.5.1 Ducts supported at each storey . 42
13.5.2 Self-loadbearing ducts . 43
13.5.3 Limitations on buckling . 43
13.6 Suspension devices for horizontal ducts . 43
13.7 Supporting construction . 44
13.8 Steel ducts . 44

v
...