prEN 1366-1
(Main)Fire resistance tests for service installations - Part 1: Ventilation ducts
- Abstract
This document specifies a method for determining the fire resistance of vertical and horizontal ventilation ducts including ancillary items such as access panels, attenuators, compensators and control dampers, which are integral part of the tested ducts. 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 used in conjunction with EN 1363-1.
Annex A provides general guidance and gives background information.
This document is not applicable to:
a) ducts whose fire resistance depends on the fire resistance performance of a ceiling or wall (where ducts are located in cavities enclosed by fire-resistant shafts or ceilings);
b) ducts containing fire dampers at points where they pass through fire separations;
c) one, two or three sided ducts;
d) fixing of suspension devices (e.g. anchors) to floors or walls.
- Status
- Not Published
- Publication Date
- 01-May-2028
- Technical Committee
- CEN/TC 127 - Fire safety in buildings
- Drafting Committee
- CEN/TC 127/WG 2 - Services
- Current Stage
- 4020 - Submission to enquiry - Enquiry
- Start Date
- 08-Oct-2026
- Due Date
- 17-Jan-2027
- Completion Date
- 08-Oct-2026
prEN 1366-1 is a CEN draft European Standard for fire resistance tests for service installations, focused on vertical and horizontal ventilation ducts. It specifies how to test a representative duct assembly, including integral access panels, attenuators, compensators and control dampers, for fire exposure from outside the duct and from inside the duct. The document is written for test laboratories, manufacturers, specifiers and certification bodies that need a common test method and a defined basis for applying the results.
What does prEN 1366-1 specify?
prEN 1366-1 specifies a test method for determining the fire resistance of ventilation ducts used in building service installations. It covers ducts in both vertical and horizontal orientations, and it assesses two exposure cases: fire attacking the duct from outside, and fire inside the duct.
The scope includes ancillary items that are part of the tested duct assembly, such as access panels, attenuators, compensators and control dampers. It is intended to be used together with EN 1363-1, which supplies the general fire test framework.
The document excludes several situations that need different evidence or a different test basis, including ducts whose fire resistance depends on the surrounding wall or ceiling, ducts with fire dampers at fire separations, one-sided, two-sided or three-sided ducts, and the fixing of suspension devices to floors or walls.
The document is organized into clauses for scope, references, terms, equipment, conditions, specimen design, installation, conditioning, instrumentation, procedure, performance criteria, test report and direct application. It also has two informative annexes.
| Annex | What it covers |
|---|---|
| Annex A | General guidance and background information for planning, running and reporting the test |
| Annex B | Determination of collapse pressure for circular steel ducts under ambient conditions |
What are the key requirements of prEN 1366-1?
prEN 1366-1 sets out a full fire test arrangement for a representative duct system, not just a piece of duct. That matters because the result depends on the duct form, joints, supports, penetration details and any items fitted inside or on the duct.
Test setup and operating conditions
Clause 4 specifies the additional equipment needed beyond EN 1363-1, including the furnace, fans for Duct A and Duct B, flow and velocity measuring stations, pressure measurement and devices for measuring thermal expansion and restraint forces. In practice, the laboratory has to be able to hold the prescribed underpressure in Duct A and the prescribed air velocity in Duct B throughout the test.
Clause 5 fixes the furnace and pressure conditions. The test is not only about heating the specimen, but also about maintaining the pressure regime that makes leakage and integrity failures visible.
Specimen design and installation
Clause 6 requires the test specimen to be representative of the complete duct assembly for which evidence is needed. The duct construction method, supports, penetrations, joints, openings, access panels, compensators and, where relevant, steel-duct details have to reflect practical use.
The document also requires the duct to be installed as it would be used in service, through a supporting construction with suitable fire resistance. For unsupported vertical ducts, the load has to reflect the weight of the unsupported height that would exist in practice.
Instrumentation and test procedure
Clause 9 defines where thermocouples and pressure measurements are taken. The measurement arrangement distinguishes between furnace conditions, unexposed surfaces, access panels, compensators and kitchen extract cases.
Clause 10 adds the operating sequence. Duct A is tested under a controlled underpressure, while Duct B is cycled between fan-on and simulated fan-off conditions so that integrity can be checked in both situations. The test also records leakage, temperature rise, and, where required, thermal expansion or restraint force.
Performance criteria
Clause 11 gives three main performance criteria: integrity, insulation and smoke leakage. Integrity is checked by the usual fire-test integrity observations and, for Duct A, by the measured leakage rate. Insulation is measured by specified thermocouple positions on the unexposed side and, for some applications, by extra thermocouples inside the duct.
For kitchen extract ducts or ducts with internal combustible linings, the document adds extra temperature checks inside Duct A. That matters because these ducts can contain grease or other combustible deposits, so the internal temperature response becomes part of the safety assessment.
Direct application of test results
Clause 13 defines what the test result can be extended to. It limits direct application to circular and four-sided rectangular ducts and sets the conditions for applying one tested size, pressure level, support arrangement or construction detail to similar cases. It also gives specific extension rules for vertical ducts, horizontal ducts, pressure differences, buckling limits, suspension devices, supporting construction, steel ducts, access panels, compensators and combustible linings.
In practice, Clause 13 is the part that buyers and specifiers use to decide whether a test result can support the size or configuration they actually intend to install.
What terms does prEN 1366-1 define?
- Fire-resistant ventilation duct - a duct used for air distribution or extraction that is designed to provide a degree of fire resistance.
- Duct A - the test condition where the duct is exposed to fire from the outside.
- Duct B - the test condition where the duct is exposed to fire from the inside.
- Combustible lining - an internal lining or coating whose reaction to fire is worse than class A2-s1, d0 when assessed in end-use condition.
- Compensator - a device used to reduce damage from thermal expansion or contraction forces.
- Supporting construction - the wall, partition or floor through which the duct passes during the test.
- Underpressure - pressure lower than ambient pressure, used here to create negative pressure in Duct A.
Who uses prEN 1366-1?
This document is used by:
- fire test laboratories running duct fire resistance tests
- ventilation duct manufacturers and system assemblers
- fire safety engineers and building services designers
- certification, approval and conformity assessment bodies
- quality managers checking that product claims are based on a defined test method
- buyers and specifiers who need to compare tested duct systems
They use it to plan a test specimen, choose the supporting construction, set up instrumentation, run the test and judge whether a result can be applied to a wider range of duct sizes or configurations.
What changed in prEN 1366-1 from the previous edition?
prEN 1366-1 is drafted to supersede EN 1366-1:2014+A1:2020.
Which standards are used with prEN 1366-1?
| Standard | What it contributes |
|---|---|
| EN 1363-1 | The general fire resistance test framework used throughout the document |
| EN 1364-1 | Standard flexible wall construction details referenced for supporting constructions |
| EN 1366-8 | Additional fire resistance test method for smoke extraction ducts when the duct is used as a smoke extraction duct |
| EN 1507 | Leakage and strength requirements for rectangular sheet metal ducts |
| EN 12237 | Leakage and strength requirements for circular sheet metal ducts |
| EN 13501-1 | Reaction-to-fire classification used for combustible lining terminology |
| EN 15882-1 | Extended application guidance for fire resistance test results for ducts |
| EN 60584-1 | Thermocouple specifications used for furnace and gas temperature measurement |
| EN ISO 898-1 | Mechanical properties of fasteners used in stress checks for suspension devices |
| EN ISO 5167-1, EN ISO 5167-2, EN ISO 5167-3 | Flow measurement principles and devices for the duct A leakage measuring station |
| EN ISO 13943 | Fire safety vocabulary used alongside the document’s terms |
What does the prEN 1366-1 document contain?
prEN 1366-1 contains detailed arrangements for vertical ducts, horizontal ducts and an alternative horizontal layout with Duct A and Duct B superposed. The figures show the furnace arrangement, openings, joints, branch details, restraint, thermocouple locations, access-panel locations, expansion measurement points and the restraint-force arrangement.
It also includes tables for specimen length, specimen size, supporting constructions and load or stress limits for suspension devices. Those tables are used when designing a test specimen and deciding whether a support or mounting arrangement is acceptable for the test.
The procedure section describes how to condition the specimen, install instrumentation, control fan operation, measure leakage and observe failure modes. The report section specifies the information to record, including test configuration, sealing method, supporting construction, measured expansions and key time-based test parameters.
Annex A gives background guidance on the apparatus, specimen design, pressure conditions and interpretation of the test. Annex B provides a separate method for measuring collapse pressure of circular steel ducts, which is used to support application decisions for certain steel-duct configurations.
Relations
- Revises
EN 1366-1:2014+A1:2020 - Fire resistance tests for service installations - Part 1: Ventilation ducts - Effective Date
- 18-Jan-2023
Get Certified
Connect with accredited certification bodies for this standard
DIBt (Deutsches Institut für Bautechnik)
German Institute for Building Technology.
DIN CERTCO
DIN Group product certification.
Kiwa BDA Testing
Building and construction product certification.
Sponsored listings
Frequently Asked Questions
prEN 1366-1 is a draft published by the European Committee for Standardization (CEN). Its full title is "Fire resistance tests for service installations - Part 1: Ventilation ducts". This standard covers: This document specifies a method for determining the fire resistance of vertical and horizontal ventilation ducts including ancillary items such as access panels, attenuators, compensators and control dampers, which are integral part of the tested ducts. 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 used in conjunction with EN 1363-1. Annex A provides general guidance and gives background information. This document is not applicable to: a) ducts whose fire resistance depends on the fire resistance performance of a ceiling or wall (where ducts are located in cavities enclosed by fire-resistant shafts or ceilings); b) ducts containing fire dampers at points where they pass through fire separations; c) one, two or three sided ducts; d) fixing of suspension devices (e.g. anchors) to floors or walls.
This document specifies a method for determining the fire resistance of vertical and horizontal ventilation ducts including ancillary items such as access panels, attenuators, compensators and control dampers, which are integral part of the tested ducts. 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 used in conjunction with EN 1363-1. Annex A provides general guidance and gives background information. This document is not applicable to: a) ducts whose fire resistance depends on the fire resistance performance of a ceiling or wall (where ducts are located in cavities enclosed by fire-resistant shafts or ceilings); b) ducts containing fire dampers at points where they pass through fire separations; c) one, two or three sided ducts; d) fixing of suspension devices (e.g. anchors) to floors or walls.
prEN 1366-1 is classified under the following ICS (International Classification for Standards) categories: 13.220.40 - Ignitability and burning behaviour of materials and products; 13.220.50 - Fire-resistance of building materials and elements; 91.140.30 - Ventilation and air-conditioning systems. The ICS classification helps identify the subject area and facilitates finding related standards.
prEN 1366-1 has the following relationships with other standards: It is inter standard links to EN 1366-1:2014+A1:2020. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
prEN 1366-1 is associated with the following European legislation: EU Directives/Regulations: 305/2011; Standardization Mandates: M/117. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
prEN 1366-1 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2026
Preskusi požarne odpornosti servisnih inštalacij - 1. del: Ventilacijski kanali
Fire resistance tests for service installations - Part 1: Ventilation ducts
Feuerwiderstandsprüfungen für Installationen - Teil 1: Lüftungsleitungen
Essais de résistance au feu des installations techniques - Partie 1: Conduits de
ventilation
Ta slovenski standard je istoveten z: prEN 1366-1
ICS:
13.220.50 Požarna odpornost Fire-resistance of building
gradbenih materialov in materials and elements
elementov
91.060.40 Dimniki, jaški, kanali Chimneys, shafts, ducts
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2026
ICS 91.140.30 Will supersede EN 1366-1:2014+A1:2020
English Version
Fire resistance tests for service installations - Part 1:
Ventilation ducts
Essais de résistance au feu des installations techniques Feuerwiderstandsprüfungen für Installationen - Teil 1:
- Partie 1: Conduits de ventilation Lüftungsleitungen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 127.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
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 supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1366-1:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 5
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Test equipment . 9
4.1 General . 9
4.2 Furnace . 9
4.3 Fan for Duct A . 9
4.4 Fan for Duct B . 9
4.5 Volume flow measuring station . 9
4.6 Condensing unit . 9
4.7 Damper . 10
4.8 Air velocity measuring station . 10
4.9 Equipment for measuring gas pressure . 10
4.10 Thermal expansion/contraction measuring device . 10
4.11 Force measuring device . 10
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 of tests . 11
6.3 Design . 11
6.3.1 General . 11
6.3.2 Minimum distance between the ducts and between ducts and furnace walls . 12
6.3.3 Configuration of duct A (horizontal only) . 12
6.3.4 Openings in duct B . 12
6.3.5 Access panel and component within duct . 12
6.3.6 Joints in horizontal ducts . 13
6.3.7 Joints in vertical ducts . 13
6.3.8 Support for vertical ducts . 13
6.3.9 Compensators . 13
6.3.10 Steel ducts . 13
6.3.11 Hangers . 13
7 Installation of test specimen . 14
7.1 General . 14
7.2 Standard supporting construction . 14
7.3 Non-standard supporting constructions . 15
7.4 Fire stopping . 15
7.5 Unsupported vertical ducts . 15
7.6 Restraint of ducts . 15
7.6.1 Inside the furnace . 15
7.6.2 Outside the furnace . 16
8 Conditioning . 16
8.1 General . 16
8.2 Water-based sealing materials . 16
9 Application of instrumentation . 16
9.1 Thermocouples . 16
9.1.1 Furnace thermocouples (plate thermometers) . 16
9.1.2 Unexposed surface thermocouples . 16
9.2 Pressure . 17
10 Test procedure . 17
10.1 General . 17
10.2 Control of conditions to permit assessment of integrity . 17
10.2.1 Duct A . 17
10.2.2 Duct B . 18
10.3 Test measurements and observations . 18
10.3.1 Integrity. 18
10.3.2 Insulation . 19
10.3.3 Thermal expansion/contraction and restraint forces . 19
10.3.4 Additional observations . 19
10.4 Termination of the test . 19
11 Performance criteria . 19
11.1 Integrity. 19
11.2 Insulation . 20
11.2.1 General . 20
11.2.2 Additional criteria for kitchen extract ducts or ducts with internal combustible
linings. 20
11.3 Smoke leakage . 20
12 Test report . 20
13 Field of direct application of test results . 21
13.1 General . 21
13.2 Vertical and horizontal ducts . 21
13.3 Sizes of ducts . 21
13.4 Pressure difference . 22
13.5 Height of vertical ducts . 22
13.5.1 Ducts supported at each storey . 22
13.5.2 Ducts supporting its own self load . 22
13.5.3 Limitations on buckling . 22
13.6 Suspension devices or mounting construction for horizontal ducts . 23
13.7 Supporting construction . 24
13.8 Steel ducts. 24
13.8.1 General . 24
13.8.2 Duct tightness . 24
13.8.3 Steel thickness for circular ducts . 24
13.8.4 Air tightness for rectangular ducts . 25
13.8.5 Steel thickness for rectangular ducts . 25
13.9 Ducts with boards . 25
13.10 Fire stopping . 25
13.11 Access panel . 26
13.12 Compensators . 26
13.13 Ducts with combustible lining . 26
Bibliography . 54
European foreword
This document (prEN 1366-1:2026) has been prepared by Technical Committee CEN/TC 127 “Fire safety
in buildings”, the secretariat of which is held by BSI.
This document will supersede EN 1366-1:2014+A1:2020.
This document has been prepared under a standardization request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
EN 1366 “Fire resistance tests for service installations” consists of the following:
— Part 1: Ventilation ducts;
— Part 2: Fire dampers;
— Part 3: Penetration seals;
— Part 4: Linear joint seals;
— Part 5: Service ducts and shafts;
— Part 6: Raised floors;
— Part 7: Conveyor systems and their closures;
— Part 8: Smoke extraction ducts;
— Part 9: Single compartment smoke extraction ducts;
— Part 10: Smoke control dampers (in course of preparation);
— Part 11: Protective Systems for Essential Services (in course of preparation);
— Part 12: Non-mechanical fire barrier for ventilation ductwork;
— Part 13: Chimneys.
Introduction
The purpose of this test is to measure the ability of a representative ventilation duct assembly / system
that is part of an air distribution system to resist the spread of fire from one fire compartment to another
with fire attack from inside or outside the duct. It is applicable to vertical and horizontal ducts, with or
without branches, taking into account joints and openings, as well as suspension devices and penetration
points.
The test measures the length of time for which ducts, of specified dimensions, suspended as they would
be in practice, satisfy defined criteria when exposed to fire from (separately) both inside and outside the
duct.
The closed end of each horizontal duct at the back of the furnace is fully restrained. Outside the furnace,
ducts exposed to fire from the outside are tested unrestrained, while ducts exposed to fire from the inside
(horizontal only) are tested restrained.
The force measurement at horizontal duct B is not mandatory but can be done on the request of the
sponsor.
The test takes into account the effect of fire exposure from the outside where a pressure differential is
maintained in the duct as well as the effect of fire entering the ducts in conditions where forced air
movement may or may not be present.
CAUTION — The attention of all persons concerned with managing and carrying out this fire resistance
test is drawn to the fact that fire testing may be hazardous and that there is a possibility that toxic and/or
harmful smoke and gases may be evolved during the test. Mechanical and operational hazards may also
arise during the construction of the test elements or structures, their testing and disposal of test residues.
An assessment of all potential hazards and risks to health should be made and safety precautions should
be identified and provided. Written safety instructions should be issued. Appropriate training should be
given to relevant personnel. Laboratory personnel should ensure that they follow written safety
instructions at all times.
1 Scope
This document specifies a method for determining the fire resistance of vertical and horizontal
ventilation ducts including ancillary items such as access panels, attenuators, compensators and control
dampers, which are integral part of the tested ducts. 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 used in conjunction
with EN 1363-1.
Annex A provides general guidance and gives background information.
This document is not applicable to:
a) ducts whose fire resistance depends on the fire resistance performance of a ceiling or wall (where
ducts are located in cavities enclosed by fire-resistant shafts or ceilings);
b) ducts containing fire dampers at points where they pass through fire separations;
c) one, two or three sided ducts;
d) fixing of suspension devices (e.g. anchors) to floors or walls.
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.
EN 1363-1, Fire resistance tests — Part 1: General Requirements
EN 1364-1, Fire resistance tests for non-loadbearing elements — Part 1: Walls
EN 1366-8, Fire resistance tests for service installations — Part 8: Smoke extraction ducts
EN 1507, Ventilation for buildings — Sheet metal air ducts with rectangular section - Requirements for
strength and leakage
EN 12237, Ventilation for buildings - Ductwork — Strength and leakage of circular sheet metal ducts
EN 13501-1, Fire classification of construction products and building elements — Part 1: Classification
using data from reaction to fire tests
EN 15882-1, Extended application of results from fire resistance tests for service installations - Part 1: Ducts
EN 60584-1, Thermocouples — Part 1: EMF specifications and tolerances
EN ISO 898-1, Mechanical properties of fasteners made of carbon steel and alloy steel - Part 1: Bolts, screws
and studs with specified property classes - Coarse thread and fine pitch thread (ISO 898-1)
EN ISO 5167-1, Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full — Part 1: General principles and requirements (ISO 5167-1)
EN ISO 5167-2, Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full — Part 2: Orifice plates (ISO 5167-2)
EN ISO 5167-3, Measurement of fluid flow by means of pressure differential devices inserted in circular
cross-section conduits running full - Part 3: Nozzles and Venturi nozzles (ISO 5167-3)
EN ISO 13943, Fire safety - Vocabulary (ISO 13943)
3 Terms and definitions
For the purposes of document, the terms and definitions given in EN 1363-1 and EN ISO 13943, together
with the following, apply.
3.1
fire-resistant ventilation duct
duct used for the distribution or extraction of air and designed to provide a degree of fire resistance
3.2
combustible lining
lining / coating on the inner surface of the duct; reaction to fire classification of the lining material (tested
in end use condition, treated as an external, non-substantial component) worse than class A2-s1, d0
Note 1 to entry: This shall be in accordance with EN 13501-1.
3.3
self-supporting duct
duct constructed e.g. from fire-protective boards without encasing a steel duct
3.4
suspension device
components used for suspending and fixing a duct from a floor or supporting a duct from a wall
3.5
supporting construction
wall, partition or floor which the duct passes through in the test
3.6
compensator
device used to prevent damage from the forces generated by expansion
3.7
access panel
cover for an inspection opening within the duct
3.8
fire protected steel duct
steel duct with an external insulation to provide fire resistance
3.9
kitchen extract duct
ductwork where combustible deposits, such as grease are likely to accumulate on its internal surfaces
3.10
component of duct
device inside duct or visible from outside the duct (examples: silencer, volume-flow controller or similar)
3.11
fixing element
pins, nails, screws, washers and other items used to secure insulation material to the ductwork
3.12
underpressure
term for an enclosed area with pressure lower than the ambient pressure; in English would be “negative
pressure”
4 Test equipment
4.1 General
In addition to the test equipment specified in EN 1363-1 the following is required:
4.2 Furnace
This shall be capable of subjecting ventilation ducts to the standard heating and pressure conditions
specified in EN 1363-1 and be suitable for testing ducts in the vertical (see Figure 1) or horizontal (see
Figure 2) orientation.
4.3 Fan for Duct A
This shall be able to produce at the start and throughout the test an underpressure of (300 ± 15) Pa within
Duct A (see Figure 4) and shall be connected either directly, or by a suitable length of flexible ducting, to
the measuring station described in 4.5.
If the duct is used in practice as a smoke extraction duct, the duct shall also be tested in accordance with
EN 1366-8. In this case, fan A shall be adjusted to (500 ± 15) Pa for testing duct a according to this
document.
4.4 Fan for Duct B
This shall be able to produce an air velocity when extracting gas from duct B (see Figure 5), of at least
3m/s measured at ambient temperature in the duct before the test. It shall be connected either directly,
or by a suitable length of flexible ducting, to the air velocity measuring station described in 4.8. The fan
shall be provided with a by-pass vent that can be opened prior to the damper described in 4.7 being shut.
4.5 Volume flow measuring station
This shall consist of a venturi, orifice plate, or other suitable device and (where necessary) an airflow
straightener, installed in straight lengths of pipe, all sized to EN ISO 5167-1, EN ISO 5167-2 and
EN ISO 5167-3. It shall be connected to the end of the condensing unit to determine the volume flow rate
of gas passing through duct A during the test. The measuring device shall be capable of measuring to an
accuracy of ± 5 %. Regardless of whether vertical or horizontal ducts are being tested, the volume flow
measuring station shall always be used in a horizontal orientation.
4.6 Condensing unit
This shall be installed between the end of duct A and the flow-measuring device and shall allow for
sufficient drainage. The gas temperature adjacent to the flow-measuring device shall be measured by
sheathed thermocouple, type K according to EN 60584-1, max. 2 mm in diameter, with an insulated hot
junction, arranged pointing upwards to allow for draining moisture. Its measuring junction shall be
located at the centre line of the measuring tube and at a distance equal to twice the diameter of the
measuring tube downstream from the flow-measuring device. The temperature measured by this
thermocouple shall not exceed 40 °C.
4.7 Damper
This shall be installed between the fan and the air velocity measuring station to shut off the airflow in
duct B during evaluation of integrity in the “fan-off” condition.
4.8 Air velocity measuring station
This shall determine air velocity in duct B and shall consist of one or two inlet nozzle(s), or other suitable
device, installed in a straight length of pipe sized to EN ISO 5167-1, EN ISO 5167-2 and EN ISO 5167-3,
connected to the end of both the vertical and horizontal duct B outside the furnace. The temperature of
the extracted hot gas shall be measured with a sheathed thermocouple type K according to EN 60584-1,
max. 2 mm in diameter, with an insulated hot junction, arranged pointing upwards to allow for draining
moisture. Its measuring junction shall be located at the centre line of the pipe and at a maximum distance
of 100 mm downstream from the flange. If larger distance is necessary, the pipe between flange and
measuring point shall be insulated.
4.9 Equipment for measuring gas pressure
This shall be provided in the laboratory, in the furnace and inside duct A. The measuring equipment for
measuring pressures differentials between duct A and the laboratory shall be provided with an accuracy
of ± 5 % relative to the intended pressure difference, i.e. 300 or 500 Pa.
4.10 Thermal expansion/contraction measuring device
This shall be provided for measuring longitudinal expansion/contraction of duct A and shall have an
accuracy of ± 1 mm.
This measurement shall be at (400 ± 50) mm from the unexposed surface of the supporting construction
(knowing that elongation outside the furnace will not be taken into account).
Any interference between thermocouples and the measurement of expansion/contraction should be
avoided; in case of any such interference, placement of thermocouples takes precedence. The result of
the expansion/contraction is not taken into account for classification, but for information of the test
sponsor.
4.11 Force measuring device
If the sponsor requests the force measurement, the appropriate measuring device shall be installed at the
point of applying restraint in duct B according to Figure 18.
5 Test conditions
The heating conditions and the furnace atmosphere shall conform to those given in EN 1363-1.
The furnace pressure shall be controlled to 15 Pa throughout the test at the mid-height position of the
horizontal ducts. For vertical ducts the furnace pressure shall be controlled to 20 Pa 100 mm below the
ceiling. The tolerance of the pressure differential is given in EN 1363-1.
If horizontal ducts A and B are tested one above the other, duct B should be at the lowest position (see
Figure 8) and the furnace pressure shall be controlled to (15 ± 3) Pa at the mid height of duct B.
Details of test conditions within the ducts during the test are given in Clause 10.
6 Test specimen
6.1 Size
6.1.1 General
For duct specimens of sizes other than those given in Table 2, the field of direct application is restricted
(see Clause 13).
6.1.2 Length
The minimum lengths of the parts of the test specimen inside and outside the furnace shall be as given in
Table 1 (see also Figures 1 and 2):
Table 1 — Minimum length of test specimen
Orientation Minimum length (m)
Inside furnace Outside furnace
Horizontal 4,0 2,5
Vertical 2,0 2,0
6.1.3 Cross-section
The standard sizes of ducts given in Table 2 shall be tested unless only smaller cross-sections are used:
Table 2 — Internal cross-section of test specimen (dimension of the open cross-section)
Duct Rectangular Circular
Width (mm) Height (mm) Diameter (mm)
A 1000 ± 10 500 ± 10 800 ± 15
B 1000 ± 10 250 ± 10 630 ± 10
6.2 Number of tests
One test specimen shall be tested for each type of installation to be evaluated.
6.3 Design
6.3.1 General
The test shall be made on a test specimen representative of the complete duct assembly on which
information is required. The method of duct construction, support and penetration shall be
representative of that used in practice.
Ducts shall be arranged as shown in Figures 1, 2 and 3.
6.3.2 Minimum distance between the ducts and between ducts and furnace walls
There is no limit to the number of ducts that may be tested simultaneously in the same furnace, provided
there is sufficient space to do so, in accordance with the dimensions shown in Figures 1, 2 and 3.
There shall be a minimum clear spacing of 500 mm between the top of a horizontal duct and the ceiling.
A minimum clear spacing of 500 mm shall be provided between the underside of a horizontal duct and
the floor. Similarly, there shall be a minimum clear spacing of at least 500 mm between either the adjacent
duct or furnace wall. The minimum clear spacing between the branch of duct A and either the adjacent
duct or furnace wall shall be 250 mm.
6.3.3 Configuration of duct A (horizontal only)
The horizontal duct A shall include one bend, a T-piece and a 500 mm long length of duct to form a short
branch duct having a cross-section of 250 mm x 250 mm for rectangular ducts (Ø 250 mm for circular
ducts), and shall be arranged as shown in Figures 2 and 3. All specimens including this branch shall be
mounted with the suspension or fixing devices as used in practice.
NOTE Figure 14 is an example for a sectional bend.
6.3.4 Openings in duct B
Two openings equal in size shall be provided, one on each vertical side of the duct inside the furnace. For
horizontal ducts the openings shall be positioned (500 ± 50) mm from the end of the duct inside the
furnace (see Figures 2 and 3). For vertical ducts the openings shall be positioned (225 ± 25) mm below
the furnace roof (see Figure 1).
In both vertical and horizontal ducts, clear openings shall have the same width/height ratio as the cross-
section of the duct. For circular ducts, the openings shall be rectangular with a width/height ratio of 4:1.
The total area of the openings shall be 50 % ± 10 % of the internal cross sectional area of the duct.
Framing of the openings shall be as in practise (to avoid weakening the duct walls in the area around the
openings).
6.3.5 Access panel and component within duct
If an access panel or any component within the duct is to be tested in a horizontal duct, it shall be mounted
as:
▪ Duct A - Located in the first straight duct section after the T-piece
▪ Duct B - Located in the first straight duct section outside the furnace after the penetration of the
supporting construction
See Figures 1 to 3 – Access panels shall be located in the underside of the duct.
If an access panel or any component within the duct is to be tested in a vertical duct, it shall be mounted
as:
▪ Duct A - Nearest edge located (200 ± 10) mm, below the supporting construction inside the
furnace
▪ Duct B - Located in the first straight duct section outside the furnace after the penetration of the
supporting construction
See Figures 1 to 3 - Note! Access panels shall be located on the widest/longest side of the duct.
The components shall be installed on the duct specimen as used in practice.
Any interference between thermocouples and the access panel or component shall be avoided; in case of
any such interference, placement of thermocouples takes precedence.
It may be possible to accommodate more than one item of in line equipment depending on furnace size
and this shall be agreed with the test laboratory. Examples of components that could be included in the
test are given in Section 3.
6.3.6 Joints in horizontal ducts
The test configuration shall include at least one joint inside the furnace and at least one joint outside it.
There shall be at least one joint in every layer of fire protection material (if applicable), both inside and
outside the furnace and in any steel duct.
Outside the furnace, the joint in the outer layer of the fire protection material shall be no further than
700 mm from the supporting construction and no nearer than 100 mm to thermocouples T . Inside the
furnace, the joint in the outer layer of fire protection material shall be located at approximately mid-span.
The distance between joints and suspension devices shall not be less than that used in practice. If the
minimum distance has not been specified, suspension devices shall be arranged so that the joint of the
outermost layer at the bottom of the insulation material (if no insulation material is present: joint of the
steel duct) lies midway between them. Centres of the suspension devices shall be specified by the
manufacturer and shall be representative of practice.
6.3.7 Joints in vertical ducts
The test configuration shall include at least one joint inside and one joint outside the furnace (see
Figure 1).
There shall be at least one joint for every layer of fire protection material, both inside and outside the
furnace and in any steel duct.
Outside the furnace, the joint in the outer layer of the fire protection material shall be no further than
700 mm from the supporting construction and no nearer than 100 mm to thermocouples T . Inside the
furnace, the joint in the outer layer of fire protection material shall be located at approximately mid-span.
6.3.8 Support for vertical ducts
Vertical ducts shall be supported on the furnace floor and penetrate through the supporting construction
(see Figure 1); the ducts shall be fixed at the level of the supporting construction as they would be fixed
in practice when penetrating a floor. This shall be as specified by the sponsor.
6.3.9 Compensators
If compensators are required in practice, they shall be incorporated in the test specimen. The
compensator shall be located within the furnace for duct A, and for duct B outside the furnace
approximately 1000 mm from the wall or floor. In cases where compensator and access panel are
included in one test specimen, the placement of the compensator takes precedence (access panel shall be
located (300 ± 50) mm from the end of the compensator).
On request of the sponsor, an additional compensator may be located in duct B inside the furnace
(1000 mm away from the supporting construction).
6.3.10 Steel ducts
Where steel ducts are used, the sponsor of the test shall provide the laboratory with evidence of the
leakage class in accordance with EN 1507 or EN 12237.
6.3.11 Hangers
When protected hangers are used for the test, they shall be insulated over their complete length.
7 Installation of test specimen
7.1 General
The test specimen shall be installed, as far as possible, in a manner representative of its use in practice.
The supporting construction selected shall be a wall, partition or floor either selected from the standard
supporting constructions in 7.2 or of the type to be used in practice which shall have a classified fire
resistance equal or greater than the intended fire resistance of the duct being tested.
Where the duct passes through an opening in the furnace wall or roof, then the opening shall be of
sufficient dimensions to allow for the supporting construction to surround all faces of the duct by at least
200 mm in case of rigid supporting constructions.
In case of flexible supporting walls, the flexible walls shall have minimum dimensions of 2500 mm x
2500 mm and have one fixed and one free vertical edge (for free edge see EN 1364-1). The horizontal
clear spacing between the outer edge of the penetration and the free edge of the flexible supporting
construction shall be (500 ± 50) mm. The clear vertical spacing between the top of the flexible supporting
construction and the top of the outer edge of the penetration shall be at least 500 mm (see also Figure 15).
7.2 Standard supporting construction
Where the type of supporting construction to be used in practice is not known then one of the standard
supporting constructions in Tables 3 and 4 or as described in the text below shall be used.
Table 3 — Standard rigid wall constructions
Type of Thickness Density Test duration t
construction mm kg/m h
Normal 110 ± 10 2200 ± 200 t ≤ 2
concrete/
150 ± 10 2200 ± 200 2 < t ≤ 3
masonry
175 ± 10 2200 ± 200 3 < t ≤ 4
Aerated 110 ± 10 650 ± 200 t ≤ 2
a)
concrete
150 ± 10 650 ± 200 2 < t ≤ 4
a)
This supporting construction may be made from blocks, bonded together with mortar or
adhesive.
A standard flexible wall construction shall be selected from the specifications as described in detail in
EN 1363-1.
Table 4 — Standard floor constructions
Type of Thickness Density Test duration t
construction mm kg/m h
Normal concrete 110 ± 10 2200 ± 200 t ≤ 1,5
150 ± 10 2200 ± 200 1,5 < t ≤ 3
175 ± 10 2200 ± 200 3 < t ≤ 4
Aerated concrete 110 ± 10 650 ± 200 t ≤ 1,5
125 ± 10 650 ± 200 1,5 < t ≤ 2
150 ± 10 650 ± 200 2 < t ≤ 4
The test laboratory may select the type of furnace roof for horizontal ducts such as aerated concrete,
reinforced concrete, reinforcement on the unexposed side concrete slabs etc.
For testing purposes: The deflection of the floor construction may be reduced, e.g. by supporting it by I-
beams. If a vertical duct passes the top floor the floor construction may be reinforced except 200 mm
around the opening.
7.3 Non-standard supporting constructions
When the test specimen is intended to be used in a form of construction not covered by the standard
supporting constructions, it shall be tested in the supporting construction in which it is intended to be
used.
7.4 Fire stopping
The fire stopping of the penetration through the supporting construction shall be as intended in practice.
The maximum width of the gap between the duct and the wall shall be accommodated as used in practice.
7.5 Unsupported vertical ducts
Where, in practice, vertical ducts are not fixed to each floor, the test specimen shall be suitably loaded to
simulate the weight of the remaining height of unsupported ducting. Rules given in EN 15882-1 shall be
followed.
NOTE Mechanical hazards might arise from this additional loading for the personnel.
7.6 Restraint of ducts
7.6.1 Inside the furnace
All ducts shall be fully restrained in all directions at the furnace wall or floor remote from the penetration
point. Where there is the possibility of the furnace wall moving then the fixings shall be made
independently of the furnace structure.
7.6.2 Outside the furnace
Only horizontal duct B shall be restrained outside the furnace. The restraining point shall be located at a
position (2000 ± 200) mm from the supporting construction and shall provide restra
...