ISO 6944-1:2024

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: +41 22 749 01 11
Email: copyright@iso.org
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
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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: copyright@iso.org
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
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