Fire Resistant Ductwork - Guidelines

BLUE BOOK European version

Fire resisting ductwork: classified according to BS EN 13501 Parts 3 and 4

European version – 1st Edition

Association Association for Specialist Specialist Fire Protection Kingsley House, Ganders Business Park, Kingsley, Bordon, Hampshire, GU35 9LU, United Kingdom www.asfp.org.uk

FIRE AND YOUR LEGAL LIABILITY 2008 produced the highest UK peace time fire losses of all time, rising over the previous year by 16% to a record £1.3bn. That’s why we must all play our part.

Why is this of relevance to me? If you are involved in provision of a fire protection package, at any level, then you share liability for its usefulness and its operation when it’s needed in fire, and that liability will still be there in the event of a court case.

I place place the order; order; it is not my responsibility to inst all the works! If it is your responsibility to specify the materials and/or appoint the installation contractor, it is also your responsibility to ensure that they can prove competency for the fire protection materials used, or the works to be carried out. It’s no longer simply a duty of care or voluntary – it’s a legal obligation. If you knowingly ignore advice that leads to a failure in the fire performance of any element of installed fire protection within a building, then you are likely to be found to be just as culpable as the deficient installer. You share liability for the provision of information required under Building Regulation 16B that tells the user of the building about the fire prevention measures provided in the building. Otherwise, the user cannot make an effective risk assessment under the Regulatory Reform (Fire Safety) Order 2005.

What What is expected expected of me? In the event of fire, and deaths, a court will want to know how every fire protection system was selected; the basis for selection of the installer, whether adequate time was provided for its installation, and whether there was adequate liaison between the different parties to ensure it was installed correctly. No ifs, no buts – it’s all contained in the Construction, Design and Management Regulations 2007. The CDM 2007 regulations, enforced by Health and Safety Executive concentrate on managing the risk, and the health and safety of all those who build, those that use the building, those who maintain it and those that demolish it – cradle to grave.

Be aware aware – the time to cons ider the above is before the event, event, not after it!

Ass As s o c i ati at i on f o r Spec Sp ecii ali al i s t Fir e Pro Pr o t ect ec t i on (ASFP) Kingsley House, Ganders Business Park, Kingsley, Bordon, Hampshire GU35 9LU, United Kingdom Fire Resisting Ductwork European version 1st Edition Editi on As Associati iatio on for for Specia cialist list Fire ire Prote rotect ctio ion n

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11 Jun 2010 www.as .asfp.o fp.org rg.u .uk k

Tel: +44 (0)1420 471 612 Fax +44 +44 (0)1420 471 611 www.asfp.org.uk The Association was formed in 1976, and currently represents the majority of UK contractors and manufacturers of specialist fire protection products, with associate members representing regulatory, certification, testing and consulting bodies. ASFP seeks to increase awareness and understanding of the nature of fire and the various forms, functions and benefits provided by passive fire protection. It is willing to make available its specialist knowledge on all aspects of fire protection and can assist designers and main contractors in identifying products suitable for specific requirements, both in the UK and related overseas markets.

Heating and Ventilating Contractors’ Association Esca House 34 Palace Court London W2 4JG T: 020 7313 4900 F: 020 7727 9268 www.hvca.org.uk The HVCA represents the interests of firms active in the design, installation, commissioning and maintenance of heating, ventilating, air conditioning and refrigeration products and equipment

Ack no wl edg emen ts nd

This document complements the 2 Edition Volume 2 of ‘Fire resisting ductwork’ which f ocuses on BS 476 Part 24 test data. It has been prepared by ASFP ASFP Task Group 6A Fire Resisting Ductwork. The contributions are gratefully acknowledged: R H Earle P Hanson M Hart T Hubbard B A James N J Macdonald L Cody N Rowan

Exova Warrington Fire, Task Group Chairman Royal Borough of Kensington and Chelsea Knauf Insulation Promat UK Ltd Fire Protection Ltd BRE Global Rockwool Ltd ASFP Technical Officer

Thanks also go to Mr T Day previously employed by BRE Global and one-time Convenor of BSI FSH/22/9 and CEN TC127 WG2 for his contributions in the early drafts of this document.

Although care has been taken to ens ure, to the best of our knowledge, that all data and information contained in t his document is accurate to the extent that it relates to either matters of fact or accepted practice or matters of opinion at the time of publication, neither the Association for Specialist Fire Protection Limited nor the co-publishers will be liable for any technical, editorial, typographical or other errors or omissions in or misinterpretations of the data and information provided in this document. Since this document may be subject to change and updating, the data and information which it contains is only correct at the date of this publication. The latest version of this publication is freely downloadable from the ASFP web site at www.asfp.org.uk/publications.. The latest date is indicated at the bottom of each page. The ASFP shall not be liable for www.asfp.org.uk/publications products delivered to the market, or for any aspect of ‘withdrawn’ products.

Compliance with this ASFP document does not of itself infer immunity from legal obligation

© Association for Specialist Fire Protection 2010 ISBN: 978-1-870409-36-0

Fire Resisting Ductwork European version 1st Edition Editi on As Associati iatio on for for Specia cialist list Fire ire Prote rotect ctio ion n

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ASFP Bl ue B oo k – Eur op ean Ver si on 1st Edi ti on : AMENDMENTS DATE

AMENDMENT

SECTION / PAGE

19/01/2009

Addition of text to Definitions

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19/01/2009

Inclusion of new figures 1-7

13- 19

18/03/2010

Inclusion of new figures

13 - 20

24/05/2010

New figure 7

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24/05/2010

Minor corrections and amendments to text and correction of typographical errors

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Fire resisting ductwork: Classified according to BS EN 13501 Parts 3 and 4 European version – 1st Edition Published by the Association for Specialist Fire Prot ection in conjunction with Heating and Ventilating Contractors Association

FOREWORD st

I am pleased to introduce this new 1 edition of the European version of the ASFP publication ‘Fire Resisting Ductwork: classified according to BS EN 13501 Parts 3 and 4’ and wholly based on EN fire tests and classifications. It provides complementary information information to the UK version entitled ‘Fire resisting ductwork: tested nd to BS 476 Part 24: 2 Edition’ which is limited to fire test data from BS 476 Part 24 tests. Both documents provide guidance to best practice for the use of ducts in buildings. The European version will be valid for tests and classifications from EN 13501 Parts 3 and 4 under the European Construction Products Directive [or proposed Regulation] whereas the BS 476-24 test method may remain useful in applications outside the European Community. The prevention of fire spread through buildings via ducted systems is of critical importance, as evidenced by serious fire losses in recent years. This document provides details and new recommendations not previously covered in other standards or codes of practice and should make a significant contribution to improved fire safety. Both the British Standard version and this European version contain sections on the diff erent types of system and their function; information on all the relevant legislation, standards and codes of practice as well as notes on penetration seals and support systems. This Edition will also introduce Data Sheets which provide details of duct systems that have been suitably fire tested and classified to EN 13501-3 and/or EN 13501-4 by a European Notified Body, and where the data is provided by a recognised third party product certification scheme which is accredited or recognised by UKAS. This European Edition provides a lead for fire engineers & engineering services designers by including European rules of application for direct [DIAP] and extended [EXAP] application of test results for fire resisting ductwork systems The ASFP recognises the key importance that fire-rated ductwork for air distribution and smoke extraction applications plays in the safe movement of air and smoke through buildings , and is particularly pleased to see these topics addressed here. We commend the guidance to designers, contractors and insurers.

Richard Earle Chairman ASFP Task Group 6 Exova Warringtonfire


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CONTENTS

1.

SCOPE ..................................................................................................................................................... 7

2

INTRODUCTION...................................................................................................................................... 7 2.1

General Notes ................................................................................................................................ 7

3.

DEFINITIONS........................................................................................................................................... 9

4.

TYPES OF DUCT SYSTEMS & FUNCTIONS ....................................................................................... 10

5.

4.1

Ventilation Duct Systems ............................................................................................................. 10

4.2

Smoke Extraction Ducts – Single and Multiple Compartments ................................................... 11

4.3

Dual Ventilation /Smoke Extraction Systems ............................................................................... 11

4.4

Pressurisation Systems................................................................................................................ 11

4.5

Kitchen Extract Systems .............................................................................................................. 11

4.6

Car Park Extract Systems ............................................................................................................ 12

FIRE RESISTING DUCTS & RELATED STANDARDS ......................................................................... 21 5.1

Related Standards ....................................................................................................................... 22

6.

A COMPARISON OF BS 476 PART 24 WITH BS EN 1366-1 FIRE TEST METHODS ........................ 22

7.

EN FIRE TESTS & CLASSIFICATIONS FOR FIRE RESISTING DUCTS ............................................ 24 7.1

General Information on EN Fire Tests ......................................................................................... 24

7.2

Ventilation Ducts .......................................................................................................................... 24

7.3

Smoke Extraction Ducts (Multi Compartments) Tested to BS EN 1366-8 ................................... 31

7.4

Smoke Extraction Ducts (Single Compartment) Tested to BS EN 1366-9 .................................. 35

APPENDIX A1: Explanatory notes for the rules of direct field of application of test data (DIAP) for ducts tested to EN 1366-1 ............................................................................................................................... 38 APPENDIX A2: Explanatory notes for the rules of extended field of application of test data (EXAP) according to BS EN 15882-1, for ducts tested to BS EN 1366-1 ........................................................... 39 APPENDIX A3: Explanatory notes for the rules of direct field of application of test data (DIAP) for ducts tested to BS EN 1366-8 .......................................................................................................................... 40 APPENDIX A4: Explanatory notes for the rules of extended field of application of test data (EXAP) according to EN 15882-8, for ducts tested to BS EN 1366-8 ................................................................. 41 APPENDIX A5: Explanatory notes for the rules of direct field of application of test data (DIAP) for ducts tested to EN 1366-9 ............................................................................................................................... 41 APPENDIX A6: Explanatory notes for the rules of extended field of application of test data (EXAP) according to EN 15882-8, for ducts tested to EN 1366-9 ....................................................................... 41 APPENDIX B: Explanatory guidance for the use of fire stopping as penetration seals, support systems & ancillary items ......................................................................................................................................... 42 APPENDIX C: Limitations of fire resisting ductwork systems ............................................................................... 44 APPENDIX D: Regulations, codes and requirements .......................................................................................... 45 APPENDIX E: Bibliography................................................................................................................................... 47 APPENDIX F: Standard specifications & method of measurement of building works .......................................... 49 APPENDIX G: Criteria of acceptability of data sheet entries ................................................................................ 50 APPENDIX H: Data Sheets .................................................................................................................................. 51

Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

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11 Jun 2010 www.asfp.org.uk

1.

SCOPE

This guidance is intended to assist the reader in understanding many of the essential details which play a significant part in ensuring that fire resisting ductwork (which includes smoke outlet) is correctly designed and installed in accordance with current BS EN standards and UK legislative requirements. The information given in this guidance focuses on the types and functions of fire resisting ductwork, and references the Building Regulations, BS EN standards, British Standards and Codes of Practice which apply to these specific types of duct. Other guidance and information, which is restricted to the use of the BS national test method BS 476 Part 24, is available in the ASFP ‘sister’ document ‘Fire resisting ductwork: tested to BS 476 Part nd 24: 2 Edition Detailed information is provided in this document on European fire tests for ducts, together with a summary of the rules for both direct and extended fields of application. Guidance is also given in respect of the fire resisting requirements for duct systems incorporating penetration seals, support systems and ancillary items, with a section relating to limitations. Drawings of typical BS EN 1366 fire test constructions are reproduced (by kind permission of the British Standards Institution) and diagrams of types and functions of various fire resisting ductwork systems are included. These are for guidance purposes only. The guidance given in this publication specifically refers to fire resisting ductwork tested to the relevant part of BS EN 1366 and does not, therefore, include advice on conventional non-fire r ated ventilation ductwork systems, or ducts containing services such as water pipes and cables. CAUTIONARY NOTE TO AL L DUCTWORK DESIGNERS, MANUFACTURERS AND INSTALL ERS General purpose DW/144 ventilation/air conditioning ductwork cannot be utilised as, or converted into, a fire resisting ductwork system unless the construction and materials of the whole system are proven by fire test and classified according to BS EN 13501 Parts 3 and 4 Further information on 'Limitations' can be found in Appendix C.

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INTRODUCTION

This publication has been produced to assist those involved in the specification, installation, inspection and verification of fire resisting ductwork tested to BS EN 1366 Parts 3, 8 or 9, and to ensure that minimum performance standards are maintained which will contribute to ensuring that fire compartments are not breached prematurely. The primary intended objective for fire safety in buildings is to limit fire to the compartment of origin, and to put it out quickly and affectively. Only then can we be sure that opportunity exists for occupants to safely escape from a building, for fire-fighters to combat a fire in a dependable manner, and for the business to be back in operation as soon as possible. Ducts can provide a primary route for fire spread through buildings, unless suitable fire prevention methods are installed from the outset. In this publication the fire prevention method focuses on the use of fire resisting ductwork, for a variety of purposes. Not all methods will be suitable for all purposes, and careful selection is often required Fire resisting ductwork can be provided either by specialist companies producing proprietary systems, or by treatment to satisfactorily constructed and supported steel ductwork with the addition of f ire insulating materials. Care must be taken when choosing a fire resisting ductwork system and checks should be made to ensure that the ductwork fire performance meets with the requirements of the relevant application. IMPORTANT All fire resisting ductwork should be tested for all aspects of the intended application, such as the orientation, shape, size, fixings and mountings of tested configurations. Many fire tests may be required to meet all the expected applications. Formal fire classifications are detailed in BS EN 13501 Parts 3 and 4. Users should satisfy themselves that the field of application meets the intended use 2.1

General Notes

Fire resisting ductwork may need to pass through compartment walls or floors that will have a prescribed fire resistance period in terms of the load-bearing capacity (stability), integrity and insulation criteria, for durations of 30 to 240 minutes. It is a requirement that where these compartment walls/floors are penetrated by ducts or other building services, the fire performance criteria for the penetrated wall or floor are maintained, such that fire in one compartment may not spread to other areas. The fire performance of a duct which penetrates a fire resisting/separating element requires careful consideration by designers and controlling authorities. The Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

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standard periods of integrity and insulation, and leakage where required, should in all cases be at least equal to those required for the penetrated element of construction. In certain circumstances, controlling authorities may waive the insulation requirement or allow a reduced period of insulation, for example, in some car parks, where enforcers consider that there is not a possibility of combustible materials being in close proximity of the ductwork. OFFICIAL GUIDANCE

The guidance given in Section 10 of the Approved Document B for B1 (Means of Escape) and B3 (Internal Fire Spread Structure) of the Building Regulations 2000 for England and Wales also refers to BS 5588: Part 9 for alternative ways in which the integrity of compartments may be maintained where ductwork penetrates fire separating elements. BS 5588 standards related to ductwork applications have been superseded by a new standard, BS 9999 Code of practice for fire safety in the design, management and use of buildings Similar recommendations are given in the Building Regulations (Northern Ireland) 2000, and in the Building (Scotland) Regulations: 2004 Statutory regulations and design codes provide the designer with prescribed per iods of fire resistance to elements of construction, which give a safe period for evacuation of people, a safe period for fire fighting and can also provide for property protection. It is vitally important for life safety that the fire resistance of the element of construction is not reduced when ductwork is routed through it. AL TERNATIVE A PPROACHES

When ventilation ductwork penetrates building compartments, the regulatory requirements and the guidance of BS 9999 should be followed using either: Method 1

Protection using fire dampers;

Method 2

Protection using fire resisting enclosures;

Method 3

Protection using fire resisting ductwork

Good practice dictates that fire dampers should not be installed within certain ductwork systems in buildings (e.g. kitchen extraction, staircase and lobby pressurisation, lift shaft ventilation, fresh air make up provision, etc.) and therefore either Method 2 or Method 3 of BS 9999 should be used, alongside an acceptable Management level as defined by BS 9999. FACTORS TO CONSIDER

It is essential to give due consideration to other factors that may be required when evaluating the suitability of a proposed system of fire resisting ductwork. These may include: 

Seismic qualification of ductwork, support system and penetration sealing method



Pressure / air carrying capacity



Materials sensitive to thermal shock



Materials susceptible to physical damage



Acoustic performance requirement of the system



Thermal performance requirement of the system



Resistance to air flow.



The suitability for cleaning, if a kitchen duct system



Any need for a smooth internal surface, for high pressure ducts.

HVCA GUIDANCE

Steel ductwork systems for air movements around buildings are generally constructed to the HVCA guide DW/144 which is a document covering a wide range of construction standards in the manufacture of sheet metal ductwork for use in low, medium or high pressure applications and includes various methods of jointing, stiffening and supporting of the ductwork. Most general purpose ventilation ductwork systems offer little or no protection against fire spread. General purpose DW/144 ventilation/air conditioning ductwork cannot be utilised as, or converted into, a fire resisting ductwork system unless the construction / materials of the whole system are classified according to BS EN 13501 Parts 3 and 4


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SELF SUPPORTING DUCTWORK

An alternative to steel ductwork systems is self supporting ductwork such as that constructed from rigid boards. Supplementary insulation may also have to be considered for these systems. FIRE TESTS

A satisfactorily constructed and supported fire resisting duct is classified according to the fire tests as called up in BS EN 13501 Parts 3 or 4. BS EN 1366 test series includes fire test methods for ventilation ducts and smoke extraction ducts – see Section 5. The European fire test documents include rules for the direct field of application of test data. The rules for extended field of application are provided as BS EN 15882-1 and BS EN 15882-8respectively

3.

DEFINITIONS

For the purpose of this document the following definitions apply. Ac cess d oo rs A closure of an inspection opening within the duct Compensator A device that is used to prevent damage from the forces generated by expansion Damper, fire A device for use in heating, ventilation and air-conditioning (HVAC) systems at fire boundaries to maintain compartments and protect means of escape in case of fire – it may have reduced smoke leakage characteristics (E or ES classification). Damper, fire & smoke A device for use in heating, ventilation and air-conditioning (HVAC) systems at fire boundaries to maintain compartments, to protect means of escape in case of fire (ES classification). Damper, smoke control A 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, and may assist fire fighting procedures. Duct /Ductwork An enclosed system of any cross sectional shape for the distribution and extraction of air within a building. Duct/ductwork - Fire resistin g A duct or ductwork used for the distribution or extraction of air, and designed to provide a degree of fire resistance when tested to BS EN 1366 -1 Duct/Ductwork - Fire resisting smoke extraction for multi-compartments A duct used for the extraction of smoke in case of fire and designed to provide a degree of fire resistance, when tested to BS EN 1366 - 8. Duct/Ductwork - Fire resisting smoke extraction for single compartments A duct used for the extraction of smoke in case of fire and designed to provide a degree of fire resistance, when tested to BS EN 1366 - 9. Duct/ductwork - Self supporting Self supporting fire rated ducts are those that are f ormed with fire protection boards, and possibly framework, without a steel duct. Duct A, B and C Duct A terminology is associated with ventilation ducts where fire is outside the duct.

Duct B terminology is associated with ventilation ducts where fire is inside the duct. Duct C is the terminology related to smoke extract ducts with fire inside the duct. Specific conditions are provided in the relevant fire test standards EN 1366 Parts 1, 8 and 9

Fire compartment A building or part of a building, comprising one or more rooms, spaces or storeys, constructed to prevent the spread of fire to or from another part of the same building, or an adjoining building. A roof space above the top storey of a compartment is included in that compartment


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Fire Resistance For ductwork systems, the ability of a component or construction to satisfy, for a stated period of time, some or all of the appropriate criteria specified in the relevant part of BS EN 1366. Further information is provided in Section 7.2.1, 7.3.1 and 7.4.1 of this document

Generally, the following performance criteria are applied to f ire resisting ductwork. Integrity and Insulation Both of these failure criteria are defined in EN 1366-1 Section 11, which also references EN 1363-1 Smoke leakage for smok e extract du cts See EN 1366-1 Section 11, which also ref erences EN 1363-1 3

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Failure of this criterion shall have occurred if the flow rate in Duct A during the test exceeds 10m /m h at normal temperature and pressure, related to the internal surface area of the duct inside the furnace Fire Separating Element A compartment wall, compartment floor, cavity barrier and construction enclosing a protected escape route and/or a place of special hazard Kitchen extract duct See section 4 Penetration An aperture through a fire separating element for the passage of a duct or ductwork, pipework, or other building services, which reduces the fire performance of the fire separating element Penetration sealing system for fire resisting ductwork The system used to maintain the fire resistance of the ductwork system where it passes through a fire separating element, in accordance with the EN 1366 Parts 1, 8 and 9 fire test methods on the entire ductwork system, seals and supports, where the duct or ductwork passes through the element of construction. Pressurisation A method of protecting an escape route against the ingress of smoke by pressurising the air within the escape route at a higher level than the air in the adjacent parts of the building. Protected shaft A shaft which enables persons, air or objects to pass from one compartment to another and which is enclosed with fire-resisting construction. Shunt System A duct or ductwork used solely for extraction in flats and maisonettes which may be used to avoid the need to provide fire dampers in extract ductwork from bathrooms and WC’s. Smoke extract duc t See section 4 Suspension devices The components used for suspending and fixing a duct from a floor; or supporting and fixing a duct from a wall. Surrounding construction /supporting construction The wall or partition or floor, through which the duct passes in the fire test.

In European standard documents this is defined as the ‘supporting construction’

4.

TYPES OF DUCT SYSTEMS & FUNCTIONS

This document does not apply to ducts containing services such as water pipes or electrical cables. It covers only ductwork that is part of the following systems for handling air, fumes or products of combustion. Typical examples are illustrated in figures 1-8. 4.1

Ventilation Duct Systems

Mechanical ventilation systems are used to extract vitiated or polluted air from a building and to supply replacement fresh or conditioned air. The necessary fans and conditioning equipment are generally located in separate plant rooms, often in a basement or on the roof. The distribution of the air involves ductwork which may be very large, extend throughout the building, penetrate compartm ent walls and/or floors and have openings in every space through which it passes. If appropriate fire precautions are not implemented, ventilation ductwork may provide a route for fire, smoke and toxic gases to spread rapidly through a building. Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

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4.2

Smoke Extraction Ducts – Single and Multiple Compartments

Smoke extraction is the evacuation from a building of products of combustion, such as smoke and toxic gases, which could otherwise reduce visibility and impair human functions. This facilitates the escape of the building occupants and assists fire fighters in locating the seat of the fire and extinguishing it. In situations where smoke clearance by natural ventilation through windows or other openings may be difficult (e.g. in large or deep basements or in high rise buildings without windows that can be opened) ductwork is required to conduct the smoke to a suitable outlet from the building. In cases where the natural buoyancy of the combustion products is not adequate to ensure the required smoke extraction rate through the ductwork, fan assisted systems are used. It may also be necessary to install ducted air inlets as part of the smoke extraction scheme, in order to provide the replacement air. If the ductwork incorporated in a smoke extraction system is wholly contained within the fire compartment, it must at least be capable of resisting the anticipated smoke temperatures generated during the development of a fire. These will generally be lower than the temperatures specified in EN 1366, which are intended to represent a fully developed fire. However, if the ductwork penetrates a fire resisting barrier, it must also be capable of providing the relevant fire resistance in a test to the relevant part of EN 1366. Further clarification of the fire testing requirements for these two different situations is provided in Section ‘5’ of this document ‘Standard Fire Tests’. 4.3

Dual Ventilation /Smoke Extraction Systems

These systems serve as a conventional ventilation system under normal conditions, but are converted to a smoke extraction system in the event of fire, thus providing an economical dual system. 4.4

Pressurisation Systems

Pressurisation is a method of restricting the penetration of smoke into certain critical areas of a building, by maintaining the air within the critical areas at pressures higher than those in adjacent areas. It applies particularly to protected stairways, lobbies and corridors, as smok e within these areas would inhibit escape, and also to fire fighting shafts serving deep basements, because of the difficulties in clearing smoke from basements. A pressurisation system is a special form of mechanical ventilation system. However, as the air supply creating the pressurisation must be maintained for the duration of a fire, fire dampers cannot be used within the ductwork to prevent the spread of fire. Any duct or ductwork penetrating fire resisting barriers must be fire resisting. 4.5

Kitchen Extract Systems

Kitchen extraction ductwork presents a particular hazard, in that combustible deposits such as grease are likely to accumulate on its internal surfaces, and may spread fire if ignited. A fire in a kitchen may spread to other areas of the building by way of the kitchen extract ductwork and may also prejudice escape routes. Guidance for the installations for kitchen extract ducts is provided in various documents. Whilst paragraphs (a) to (g) may not be exhaustive, they attempt to list the common requirements with references the regulatory guidance in Approved Document B 2006, where applicable, and other documents. 4.5.1

Means of Escape (Appr oved Docum ent B: B1)

a)

Approved Document B: 2006, Paragraph 5.50 Non-domestic kitchens are required to have separate and independent extraction systems, because of the polluted nature of the extracted air. The extracted air should not be re-circulated.

b)

Approved Document B 2006, Paragraph 10.10 Fire dampers should not be installed in extraction ductwork serving kitchens due to the build up of grease.

c)

Any kitchen extract duct or ductwork penetrating fire resisting barriers must be fire resisting between the kitchen and the external weathering cowl. The fire resistance requirement is normally 30 minutes, unless the duct also penetrates a compartment separation wall/floor where the fire resistance period and criteria should meet any higher r equirement of the compartment wall/floor.

d)

British Standards Although Approved Document B 2006 does not provide guidance on kitchens other than in small premises and residential care homes, the AD-B states in paragraph 0.22 that supplementary guidance is given in British standards, and AD-B paragraph 5.53 references BS 5720. (The ASFP considers that paragraph 2.5.2.3 applies)


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BS 5720 paragraph 2.5.2.3

States that kitchen extract ductwork should be enclosed with fire resisting construction where passing through other floors between the kitchen and the external weathering cowl. The canopy, ducting and lagging forming the kitchen extract duct should made from non-combustible material BS 9999

Paragraph 32.5.7 Table 31 requires a kitchen to be enclosed with fire resisting construction. e)

Guidance for Hospitals is given in HTM 05-02. In most cases, unless a suitable automatic extinguishing arrangement is provided, kitchens are required to be enclosed with f ire resisting construction. Consequently the extract ductwork also needs to be enclosed with fire resisting construction where passing outside the kitchen enclosure up to its discharge to external air. The required fire resistance is to be achieved from inside the duct, to prevent a fire from inside the duct breaking out and spreading to other areas in the building.

NOTE:

ASFP emphasises that regular internal cleaning of kitchen extract ducts is an essential part of all fire risk assessments and planned maintenance programmes in accordance with HVCA publication DW/172.

4.5.2

Compartmentation (Approved Document B: B3)

a)

Approved Document B 2006, Paragraph 10.9 and 10.10 Where a kitchen extract duct (an air handling duct) passes through fire separating elements the integrity of those elements should be maintained. Fire dampers (known as Method 1) are not suitable for extract ductwork serving kitchens. This is due to the likely build up of grease within the duct, which can adversely affect the effectiveness of any dampers. Therefore a fire resisting enclosure (known as method 2) or fire resisting duct (known as Method 3) is recommended.

b)

BS ISO 6944-2: 2008 Although BS EN 1366 Parts 1, 8 and 9 do not have specific fire performance requirements for kitchen extract systems, the specifier may select a system which has been tested to BS ISO 6944-2: 2008 which has been developed specifically for this application.

NOTE:

Regardless of the publication of BS ISO 6944-2 the UK regulators may choose not to adopt all published standards in regulatory documents. Specific regulatory information is available in Approved Document B as guidance to building regulations.

4.6

Car Park Extract Systems

Car parks are required to have separate and independent extraction systems, because of the polluted nature of the extracted air. It is recommended that fire dampers should not be installed in extraction ductwork serving car parks. Any duct or ductwork penetrating fire resisting barriers must be fire resisting.


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5.

FIRE RESISTING DUCTS & RELATED STANDARDS

Fire resisting ducts

Smoke control ducts

Product standard

Product standard

EN 15871

EN12101-7

Fire resisting ducts

Smoke and heat control duct systems

Classification standard

Classification standard

EN 13501-3

EN 13501-4

Fire classification of construction products and building elements - part 3: classification using data from fire resistance tests on components of normal building service installations

Fire classification of construction products and building elements - part 4: classification using data from fire resistance tests on components of smoke control systems

Test standard

Test standard

EN 1366-1

EN 1366-8

Fire resistance tests for service installations: Ducts

Fire resistance tests for service installations: Smoke extraction ducts (multi compartment) Test standard EN 1366-9 Fire resistance tests for service installations: Single compartment smoke extraction ducts

Extended field of application standard

Extended field of application standard

EN 15882 -1

EN 15882 -8

Extended applications of test results for fire resistance tests for service installations: Ducts

Extended applications of test results for Smoke extraction ducts


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5.1

Related Standards

CLEANLINESS EN 15780 Cleanliness of ducts FIRE AND DISTRIBUTION SYSTEMS BS EN 15423 ‘Fire precautions for air distribution systems in buildings’

6. A COMPARISON OF BS 476 PART 24 WITH BS EN 1366-1 FIRE TEST METHODS The test data arising from the previous BS 476 Part 24 tests and harmonised BS EN tests are not directly comparable or interchangeable. The harmonised EN test methods are acceptable for use across Europe and mitigate the costs of testing for manufacturers. The following table illustrates the differences, for simple ventilation ducts [see 8.1] Note that there are additional fire tests for smoke extraction ducts: i.e. BS EN 1366-8 for multi-compartment smoke extraction ducts [see 8.2] and BS EN 1366-9 for single compartment smoke extraction ducts [see 8.3] ITEM

BS 476 Part 24 / ISO 6944 (1985)

BS EN 1366-1 / ISO 6944-1 (2008)

Apparatus

Furnace controlled to ISO 834

Furnace controlled to EN 1363-1 Thermal movement measuring device (Duct A) Force measuring device (Duct B)

Device for measuring restraint forces Thermocouples for measuring internal temperature of furnace and internal and external temperature of test specimen(s) Equipment for measuring gas pressures in furnace and in duct

Equipment for measuring gas pressures in furnace and in Duct A

Extract fan required for Duct A to produce and maintain an underpressure of 300Pa.

Extract fan required for duct A to produce and maintain an underpressure of 300Pa connected to measuring station between duct and fan.

Extract fan with capacity to produce gas velocity at 3m/sec at ambient at start of test. Allows use of flow rate controller to achieve this. (Duct B).

Extract fan with capacity to produce gas velocity at 3m/sec at ambient at start of test. Allows use of flow rate controller to achieve this. (by-pass valve and damper) (Duct B). Volume flow measuring station Condensing unit Velocity measuring station (Duct B)

Fire exposure

ISO 834 time temperature curve

EN 1363-1

Measurement of temperature of flue gases in duct

At centre of cross-section, at penetration No specific requirement to measure point and 2m from this outside furnace

Pressure condition in duct A

Neutral pressure below horizontal duct and set to –300 ± 10Pa at start of test relative to ambient conditions. No subsequent adjustment of fan required for duct A


22

-300 Pa at start of test and maintained at this value though out test


ITEM

BS 476 Part 24 / ISO 6944 (1985)

BS EN 1366-1 / ISO 6944-1 (2008)

Velocity in duct B

Set to 3m/sec measured at ambient at start of test but no further adjustments made.

3m/sec at start of test and maintained at this during test except when fan shut off to make integrity measurements

Fan shut off prior to integrity evaluations then switched back on after. Integrity determined. Minimum dimension of ducts

Cross section of ducts

In furnace

In furnace

3m length horizontal duct

4m length horizontal duct

2m length vertical ducts


Outside furnace

Outside furnace

2.5 m length horizontal duct

2.5m length horizontal duct

2 m length vertical ducts


Duct A & Duct B:

Duct A: 1000 mm ± 10 wide 500 mm ± 10 high 800mm ± 10 diameter

1000mm by 250 mm

NOTE: No provision in Part 24 to cover circular ducts specifically

Duct B: 1000 mm ± 10 wide 250 mm ± 10 high 630 mm ± 10 diameter

Minimum separation

At least 500 mm

500 mm ± 50

Elbow – duct A

Same-cross section area as duct. End of elbow sealed

Cross section of 250 mm by 250 mm

Duct restraint

Both ducts abut to furnace wall with end sealed where it abuts.

Both ducts abut to furnace wall with end sealed where it abuts.

Full restraint provided 2000 mm ± 50 outside furnace from penetration point

Full restraint provided 2000 mm ± 50 outside furnace from penetration point (duct B only)

Joint arrangement in duct protection

At least two joints inside furnace and one outside (vertical ducts one joint inside furnace and one outside)

one joint inside furnace and one outside [no greater than 700 mm from penetration point] (vertical ducts one joint inside furnace and one outside)

Openings in duct B

At least half the cross-section of the duct cross section

At least half the cross-section of the duct cross section but clear this is the total and each opening is half of that

Supporting construction

Not specifically specified

Various supporting constructions specified in some detail

Assessment of fire resistance

Stability

Stability no requirement other than observing general behaviour in furnace

Integrity (cotton pad, gaps, flaming)

Integrity (volume flow rate-15m³/m² h), cotton pad, gaps, flaming)

Insulation

Insulation: additional requirements for ducts with combustible linings Smoke leakage (10m³/m² h)


23


7. 7.1

EN FIRE TESTS & CLASSIFICATIONS FOR FIRE RESISTING DUCTS General Information on EN Fire Tests

The European fire resistance tests and classification system for ducting have their foundations in the ISO 6944 method - which is synonymous with the UK fire resistance test method BS 476: Part 24 method of test. The International Standard has been used to specify a method of test and criteria for the determination of vertical and horizontal ventilation with the general purpose to measure the ability of a representative duct or duct assembly to resist the spread of fire from one compartment to another. It has also been applied to smoke outlet ducts and to kitchen extract ducts - but it contains limited guidance for the use of ducting in extended fields of application. In contrast, the BS EN 1366 test series includes separate fire test methods for ventilation ducts, as BS EN 13661, and for smoke control ducts, as BS EN 1366-8 for multi-compartment use and as BS EN 1366-9 for single compartment use. It is important to differentiate between single and multi-compartment smoke extract systems. The European fire test documents include rules for the direct field of application of test data, and a separate series of documents (pr EN 15882-x) is in preparation to prescribe methods for agreed rules for extended fields of application of test data from the fire tests. 7.1.2

General infor mation on the field of application of test data for classification

Classification standards BS EN 13501 parts 3 and 4 inform readers which tests must be undertaken to obtain suitable classification for fire performance. BS EN 13501-3 applies to fire resisting ducts, and BS EN 13501-4 applies to smoke control ducts. The principle differences between the BS 476 Part 24 test method [derived from ISO 6944] and the European tests are outlined in Section 6 of this document. The field of application from tests to BS EN 1366 may be split into two distinct categories viz. direct and extended fields of application. See Appendices A and B for discussion and further details Direct field o f applic ation (DIAP)

Rules for direct field of application are included in the fire test standards BS EN 1366-1, BS EN 1366-8 and BS EN 1366-9 according to the application concerned. The rules are derived from information obtained from tests carried out in accordance with BS EN 1366 at UKAS accredited or recognised laboratories. The test results achieved by a particular design may be directly applied to a limited number of variations (e.g. a reduction in duct size) without recourse to expert advice, providing the design remains substantially as tested. ASFP has not reproduced the DIAP rules in this document since they are subject to change and improvement by CEN. The ASFP recommends that the latest copy of EN 1366 Parts 1, 8 and 9 are used for any reference purposes. ASFP has provided ‘an overview’ of the likely rules in Appendix A of this document." Extended applicatio n (EXAP)

The rules for extended field of application of test data are formulated from experience of accumulative test data for various ductwork installations, based on test data from BS EN 1366 Parts 1, 8 or 9, which may be supplemented by appropriate and relevant historical test evidence generated from other sources. The assessment considers changes in the tested design beyond the scope of direct application and may also consider variations to the tested design. For example, an increase in duct size which necessitates the inclusion of a joint in the duct walls. The EXAP rules are contained in stand alone documents BS EN 15882-1 in the case of tests made to BS EN 1366-1 and in BS EN 15882-8 for smoke control ducts tested to BS EN 1366 Parts 8 and 9. ASFP has not reproduced the EXAP rules in this document since they are subject to change and improvement by CEN. The ASFP recommends that the latest copy of EN 15882 Parts 1 and 8 are used for any reference purposes. ASFP has provided ‘an overview’ of the likely rules in Appendix A of this document which we hope will aid the understanding of the readers of this document. 7.2

Ventilation Ducts

7.2.1

BS EN 1366-1 Fire resistance tests for service installations : ducts

This EN test for ventilation ducts is also used as a precursor to the ‘Smoke Extract’ ducts – see sections 7.3 and 7.4 - where fire insulation is required to be demonstrated. The test is conducted without the involvement of fire dampers. It is applicable to vertical and horizontal ducts, taking into account joints, air supply and exhaust openings, as well as suspension devices and penetration seals. Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

24


The performance of the duct assembly is measured in terms of its ability to withstand exposure to high temperatures, by setting criteria by which the resistance to fire containment (integrity), the thermal transmittance (insulation) functions, together with the leakage rate of the duct can be judged. The standard temperature/time fire exposure specified in BS EN 1363-1 is representative of one possible fire exposure condition at the fully developed fire stage. The method of test does not quantify the behaviour of a duct for a precise period of time in a real fire situation, but can be classified for direct field of application to show compliance with fire resistance requirements in regulations or other safety specifications, and enables comparisons to be made between constructions. The specimen that is subject to the fire test must be designed and constructed to be representative of how it would be constructed on site. Two ducts are tested, one where the fire is outside (Duct A), and one where the fire is inside (Duct B). Both ducts may be tested in either a horizontal or vertical orientation (General views are provided in Figures 10 to 13). It is applicable only to four sided and circular ducts. One, two and three sided ducts are not covered. Note: Where steel ducts are used, these shall have class A leakage in accordance with prEN 1507.


25


Figure 10 General arrangement for vertical ducts as tested to BS EN 1366-1


26


Figure 11 General arrangement for horizontal ducts as tested to BS EN 1366-1

The minimum length of the specimen duct required by the test standard is 4.0m inside the furnace and 2.5m outside the furnace for horizontal ducts, and 2.0m inside the furnace and 2.0m outside the furnace for vertical ducts. The horizontal Duct A is fitted with a branch duct within the furnace. The cross section of Duct A for test is 1000mm x 500mm internally with the branch section of 250mm x 250mm. (For circular ducts, the duct the diameter is 800mm with the branch of 250mm diameter). A connection from the end of the Duct A outside the furnace is taken via a condensing unit and leakage measurement equipment, to a fan that maintains an under-pressure of -300 ± 15Pa inside the duct. (The condenser traps and removes water from any leakage gases, by reducing the temperature of any gas flow to below 40 deg C so eliminating erroneous leakage measurements due to moisture).


27


(Note: for ducts that are intended for use as smoke extract ducts, and will be tested to EN 1366-8, the Duct A will require to be tested at the higher under-pressure of -500 Pa)

The cross section of Duct B for test is 1000mm x 250mm. (For circular ducts, the duct diameter is 630mm). A fan is also connected to the end Duct B outside the furnace that induces a furnace gas velocity of 3m/s within the duct, drawn through openings in the sidewall of the duct within the furnace. The velocity is maintained at 3m/s during the ‘fan on’ periods during the test. Every 30 minutes of the test the fans are switched off for five minutes to evaluate the integrity of the duct in the ‘fan off’ situation. The test specimen is subjected to fire on all four sides. The standard time/temperature exposure is followed. The furnace pressure is controlled to 15±3Pa at the mid height on horizontal ducts, or to 20±3Pa 100mm below the ceiling for vertical ducts, compared to that of the laboratory. Thermocouples are applied to the non-fire face of the duct, to the supporting structure and penetration seal outside the furnace, as required by the standard. Additional thermocouples may be included within the duct where a duct has a combustible lining, in order to gain additional data on the fire performance. (Although this is similar to the Annex in BS476: Part 24, this method is not primarily intended for evaluation of a duct system intended as a kitchen extract duct.) The tested duct assembly is judged against three performance criteria. These are: Insulation Insulation failure shall be as defined in EN1363-1. Only thermocouples placed a distance 325mm from the duct penetration detail, outside of the furnace are used to determine the average temperature rise (140°C) of test specimen. All fixed thermocouples and the roving thermocouple may be used to determine the maximum temperature (180°C) rise. Ducts with combustible linings shall also be subject to the insulation failure criteria in EN1363-1 on thermocouples placed inside the duct, inside the furnace. (Duct A). Integrity Integrity failure shall also be deemed to have occurred if any of the following are observed.

a)

Integrity failure as defined in EN 1363-1. (When a cotton pad is ignited, or gap openings, or when sustained flaming, of duration at least 10s, appears on the unexposed face of the test specimen outside the furnace).

b)

When the volume flow rate measured in Duct A exceeds 15m /m /hr at NTP (20°C and 1013mbar) relative to the internal surface of the duct, inside the furnace.

3

2

Smoke Leakage A failure of the smoke leakage criteria, shall be deemed to have occurred if the flow rate in Duct A during the test 3 2 exceeds 10m /m /hr at NTP (20°C and 1013mbar) relative to the internal surface of the duct, inside the furnace. Stability Note: The loss of stability or the partial collapse of Duct B inside of the furnace is not a failure criterion in this test. However, the partial collapse or loss of cross section in this test may have implications for the expected behaviour for any subsequent Duct C smoke duct test.

Loss of stability or partial collapse in Duct A will be reflected in the flow rate leakage criteria above.


28


Figure 12 General arrangement for location of thermocouples on vertical ducts, inside the test furnace, as tested to BS EN 1366-1


29


Figure 13 General arrangement for location of thermocouples on horizontal ducts, inside the test furnace, as tested to BS EN 1366-1

7.2.2

DIAP rules for the direct field of applicatio n of test data for fire resisting ventilation ducts tested to BS EN 1366-1

See BS EN 1366 Part 1 An overview is provided in Appendix A1 7.2.3

EXAP rules for the extended field of applicatio n of test data for ventilation ducts tested to BS EN 1366-1

See BS EN 15882-1 An overview is provided in Appendix A2 Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

30


7.2.4

Classific ation of fire resisting ventilation ducts BS EN 13501 Part 3

Some readers may not be familiar with the CEN European system of tests and classification, etc. The system can be briefly summarised as follows:The product standard will state which European classification system applies to the product being considered. The Classification system BS EN 13501-3 will tell readers which fire tests have to be undertaken to allow a classification for fire performance to be made The fire test standard will normally include the direct rules for the field of application of the test data obtained. A separate document will provide the rules for extended field of application, beyond the limits of the test data obtained For fire resisting ducts, the following classes are defined: EI 15 E

20

30 30

45

60

90

120

180

240

60

The classification shall indicate if the performance criteria are satisfied by fire from inside or fire from outside or both, and whether it applies to vertical or horizontal orientations or both. The additions “i o”, “o i“ or →

“i

↔

→

o” shall be used respectively together with “ve” and/or “ho” to indicate orientation (vertical and horizontal).

For example, a classification EI30 (ve ho I o) indicates a ventilation duct capable of satisfying 30 min integrity and insulation, from inside to outside and vice-versa in both vertical and horizontal applications. ↔

The classification S shall be included, based on satisfaction of the ambient smoke leakage criterion. This shall be based on a pass/fail test for the leakage. For example, a classification EI30 (ve ho i o) S indicates a duct with the same performance as above but additionally satisfying the leakage criterion (10 m³/(m²·h). ↔

Failure of the suspension devices does not constitute failure of the test specimen unless it leads to failure of either E or EI. 7.3

Smoke Extraction Ducts (Multi Compartments) Tested to BS EN 1366-8

7.3.1

BS EN 1366-8: 2004: Fire resistance tests for service installations : smoke extraction ducts (multi compartment)

This test method is applicable to fire resisting ducts that have already passed the appropriate period to BS EN 1366-1 (Ducts A and B), - where the Duct A has been tested a differential pressure 500Pa. (A greater under pressure than the standard pressure indicated in BS EN 1366-1). Smoke extraction ductwork shall be made of non-combustible materials (Euro class A1 or A2). The specimen that is subject to the fire test must be designed and constructed to be representative of how it would be constructed on site.


31


Figure 14 General arrangement for horizontal smoke extract ducts, as tested to BS EN 1366-8 for multi-compartment use


32


Figure 15 General arrangement for vertical smoke extract ducts, as tested to BS EN 1366-8, for multi-compartment use.

Whilst the test method has been designed to cover both vertical and horizontal smoke extraction ducts, provided both horizontal and vertical tests have been carr ied out to BS EN 1366-1 on the specific system, a vertical duct need not be evaluated to this method - provided that it is tested in a horizontal orientation to this method. If however, the system in practice is only to be used for vertical applications in smoke extraction, (that is, the horizontal orientated ducts were not tested in BS EN 1366-1), then it will need to be tested in the vertical orientation to the test method here. The duct is tested with fire on the inside of the duct (Duct C) See Figure 15. It is applicable only to four sided and circular ducts. One, two and three sided ducts are not covered.


33


The minimum length of the specimen duct required by the test standard is 3.0m inside the furnace and 4.2m outside the furnace for horizontal ducts, and 2.0m inside the furnace and 4.25m outside the furnace for vertical ducts. The cross section of Duct C for test is 1000mm x 250mm. (For circular ducts, the duct diameter is 560mm). A fan is connected to the end of the duct outside the furnace that induces a furnace gas velocity of 2m/s ±15% within the duct, drawn through openings in the sidewall of the duct within the furnace. A perforated plate, appropriate to one of three prescribed differential pressures of –150Pa, -300Pa or –500Pa is incorporated within the duct, 250mm outside the furnace. The test specimen is subjected to fire on all four sides. The heating conditions conform to those specified in EN 1363-1 (standard heating curve) and the selected differential pressure maintained to ±3%. The furnace pressure is controlled to 15±3Pa at the mid height on horizontal ducts, or to 20±3Pa 100mm below the ceiling for vertical ducts, compared to that of the laboratory. (Note: it is the differential duct pressure that is controlled during the test, not the air velocity.) Thermocouples are applied to the non-fire face of the duct, and to the supporting structure and penetration seal outside the furnace, as required by the standard, although these are not required to demonstrate insulation performance and are for information only. (Insulation performance is taken from the EN 1366-1 test data). To facilitate observations of reduction of cross-section, an observation window is located at the end the duct. 7.3.2

DIAP rules for the direct field of application of test data for smoke extraction duct test data when tested to BS EN 1366-8

See BS EN 1366 Part 8 - An overview is provided in Appendix A3 The DIAP rules are normally part of the EN test standard The tested duct assembly is judged against three performance criteria. These are: Insulation Test results from the BS EN 1366-1 test are deemed to demonstrate the insulation performance of the duct. Integrity Integrity failure shall also be deemed to have occurred if any of the following are observed as defined in BS EN 1363-1. When the cotton pad is ignited or when sustained flaming, of duration at least 10s, appears on the unexposed face of the test specimen outside the furnace. Smoke Leakage A failure of the smoke leakage criteria, shall be deemed to have occurred if the leakage flow rate through the 3 2 duct section outside of the furnace, as determined by the Oxygen sensor method exceeds 10m /m /hr at NTP (20°C and 1013mbar) relative to the internal surface of the complete duct (inside and outside of the furnace) Reduction in Cross-section The internal dimensions (width and height for a rectangular duct, or diameter for a circular duct) shall not decrease by more than 10% during the test. Mechanical Stability The duct inside the furnace collapses, so that is can be judged as not being able to maintain its smoke extraction or fire resistance function. 7.3.3

EXAP RULES for extended field of application for smoke extraction ducts (multi ple compartm ents) tested accordin g t o B S EN 1366-8

See BS EN 15882-x (to be published) An overview is provided in Appendix A4 7.3.4

EI

Classific ations for Multi-comp artment smoke contr ol system ducts BS EN 13501-4

30

60

90

120

The classification is completed by the suf fix “multi” to indicate suitability for multi-compartment use. In addition, the symbols “ve” and/or “ho” indicate the suitability for vertical and/or horizontal use. “S” indicates a leakage rate of less than 5m³/(h.m²). ‘500’, ‘1000’ or ‘1500’ indicates that when tested at these negative pressures the duct is suitable for use over the range from the tested negative pressure up to a positive pressure of 500 Pa.


34


7.4

Smoke Extraction Ducts (Single Compartment) Tested to BS EN 1366-9

7.4.1

Fire resistance tests for service installations: single compartment smoke extraction ducts tested according to BS EN 1366-9

This part of EN 1366 specifies a test method for determining the fire resistance of horizontal smoke extraction ducts that are used for single compartment applications only. In such applications, the smoke extraction system is only intended to function up to f lashover (typically 600 °C but other temperatures may be used). It is applicable to smoke extraction ducts that do not pass through into other fire compartments. Note: unlike the test in BS EN 1366-8, it is not a prerequisite that the duct is tested to BS EN 1366-1. For smoke extraction ducts that pass through into other compartm ents, the method of test described in BS EN 1366-8 should be used. It is applicable only to four sided and circular ducts. One, two and three sided ducts are not covered. This method of test is only suitable for ducts constructed from non-combustible materials (Euro class A1 and A2s1, d0). The method described in this test standard is complex and requires sophisticated instrumentation. Whilst it is permitted, it is not recommended that multiple assemblies are tested together. The specimen that is subject to the fire test must be designed and constructed to be representative of how it would be constructed on site. A single duct is tested, with fire on the inside of the horizontal duct. See Figures 16


35


Figure 16 General arrangement for horizontal smoke extract ducts, as tested to BS EN 1366-9 for single compartment use.

The minimum length of the specimen duct required by the test standard is 3.0m inside the furnace and 4.2m outside the furnace. The cross section of duct for test is 1000mm x 250mm. (For circular ducts, the duct diameter is 560mm). A fan is connected to the end of the duct outside the furnace that induces a furnace gas velocity of 2m/s ±15% within the duct, drawn through openings in the sidewall of the duct within the furnace. A perforated plate appropriate to one of three prescribed differential pressures of –150Pa, -300Pa or –500Pa is incorporated within the duct, 250mm outside the furnace. The test specimen is subjected to fire on all four sides. The heating conditions and the furnace atmosphere conform to those specified in EN 1363-1 (or, if applicable, EN 1363-2) until 600 °C is reached. The mean temperature of the 6 furnace thermocouples shall be reached between 5 to 10 minutes from igniting the first furnace burner. After 10 minutes this temperature shall be maintained between +70, -0 °C for the rest of the test. The furnace pr essure shall be controlled to (15 ± 3) Pa throughout the test at the mid-height position of the ducts in the furnace. Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

36


To facilitate observations of reduction of cross-section, an observation window is be located at the end the duct or other suitable place. Smoke extraction ductwork, for use in combination with smoke exhaust fans and which is intended to extract smoke from the compartment to outside, without passing through other fire compartments. Thermocouples to measure insulation are not required to the duct, nor to the supporting structure or penetration seal outside the furnace. The tested duct assembly is judged against three performance criteria. These are: Smoke Leakage A failure of the smoke leakage criteria, shall be deemed to have occurred if the leakage flow rate through the duct section outside of the furnace, as determined by the Oxygen sensor method exceeds 3 2 10m /m /hr at NTP (20°C and 1013mbar) relative to the internal surface of the complete duct (inside and outside of the furnace) Reduction in Cross-section The internal dimensions (width and height for rectangular duct or diameter for circular duct) of the smoke extract duct shall not decrease by more than 10% during the test inside and outside of the furnace. Mechanical Stability The duct inside the furnace collapses, so that is can be judged as not being able to maintain its smoke extraction or fire resistance function.

(Fire insulation and fire integrity are not r equired) 7.4.2

Direct field of applic ation for single compartment smoke extract ducts tested to BS EN 1366-9

The DIAP rules are normally part of the BS EN test standard An overview is provided in Appendix A5 7.4.3

Extended field of application for singl e compartm ent smoke extract ducts fire tested to BS EN 15882-Y

See BS EN 15882-Y (to be published) An overview is provided in Appendix A6 7.4.4

Classific ation for singl e compartm ent smoke contr ol ducts accordi ng to BS EN 13501-4

E300

30

60

90

120

E600

30

60

90

120

The classification is completed by the s uffix “single” to indicate suitability for single compartment use only. In addition, the symbols, “ve” and/or “ho” indicate the suitability for vertical and/or horizontal use. “S” indicates a leakage rate of less than 5m³/(h.m²). ‘500’, ‘1000’ or ‘1500’ indicates that when tested at these negative pressures the duct is suitable for use over the range from the tested negative pressure up to a positive pressure of 500 Pa.


37


APPENDICES A1 to A6

APPENDIX A1: Explanatory notes for the rules of direct field of application of test data (DIAP) for ducts tested to EN 1366-1 A.1.1

INTRODUCTION

The formal DIAP rules are part of the European test standard EN 1366-1 which is published as BS EN 1366-1 in the United Kingdom. The formal rules allow certain variations in ductwork systems without declassification of the data from the tested ductwork configuration, and without the need to seek further expert/specialist fire safety advice. Section A.1.2 provides an overview of the formal rules for direct field of application of data obtained from fire tests to BS EN 1366-1 A.1.2

Over vi ew o f t he c ri ti cal par amet ers fo r d ir ect ru les of app li cat io n, DIAP

The following text provides a brief description of the principles behind the rules for the direct field of application of test results. For full details refer to BS EN 1366-1, Section 13. Shape of duct s

The field of direct application only covers circular and rectangular ducts with 4 sides. Vertical and horizontal duct s

Test results are not interchangeable between vertical and horizontal ducts. Sizes of du cts

Provided that the standard sizes of duct are tested, as detailed within the test standard, a limited extrapolation is permitted for larger sizes of duct. Ducts smaller than those tested are also covered. Pressure difference

The maximum tested under-pressure in duct A is applicable to the same maximum over-pressure provided that the integrity criteria were satisfied for duct B. Lower values of under and overpressures are also allowed. If higher values are possible then additional testing may be needed. Height of vertical ducts •

Ducts supp orted at each sto rey

Limits are given for the distance between supporting constructions and for the size of the ducts compared to the distance between supporting constructions. The latter is to avoid buckling of the ducts. •

Self load bearing duct s

If additional loads are applied to the tested duct then the overall height between supports may relate to the load applied in the test. Guidance is given on the ratio between the size of the duct and the distance between supporting constructions - to prevent damage to the duct assembly due to buckling of the vertical duct. Suspension devices for horizontal ducts

Maximum values are given for tensile stress and shear stress within the steel suspension devices. Guidance is also given with regard to the length and positioning of the suspension devices. The bending stress in the horizontal load bearing member of the suspension device shall not exceed that tested. Supporting construction

Guidance is given with regard to alternative fire resistant supporting constructions, through which the f ire resisting duct passes, compared to that utilised in the fire test. Steel duc ts

Guidance is given with regard to the leakage values of steel ducts and stiffeners fitted to a steel duct.


38


APPENDIX A2: Explanatory notes for the rules of extended field of application of test data (EXAP) according to BS EN 15882-1, for ducts t ested to BS EN 1366-1 A.2.1

INTRODUCTION

The formal EXAP rules are published separately as BS EN 15882-1 in the United Kingdom. The formal rules allow certain variations in ductwork systems without declassification of the data from the tested ductwork configuration. Section B2 provides an overview of the formal rules for the extended field of application of data obtained from fire tests to BS EN 1366-1 A.2.2

Over vi ew o f t he c ri ti cal par amet ers fo r ex ten ded fi eld of app li cat io n, EXAP

The following provides a brief description of the principles behind the rules for the extended field of application of test results. For full details refer to BS EN 15882-1. Shape of duc ts

The test results are not interchangeable between ducts with a different shape, e.g. circular and rectangular ducts. Vertical and horizont al ducts

Test results are not interchangeable between vertical and horizontal ducts. Fire exposu re of ducts

Test results are not interchangeable between internal fire exposure and external fire exposure. Sizes of du cts

For rectangular ducts with a cross section larger than 1250mm wide x 1000mm high and for circular ducts with a cross section larger than 1000mm diameter, additional tests are required as described in BS EN 15882-1. If additional tests are undertaken as described in prEN15882-1, the maximum sizes may be extended up to 2500mm wide x 1250mm high for rectangular ducts and up to 1250mm diameter for circular ducts. Pressure diff erence

If pressure differentials are required for the ducts that are higher than those tested or ±300Pa, whichever is the greater, then additional tests are required as described in BS EN 15882-1. Height of vertical ducts

If the unsupported height between floors is greater than 5m then additional tests are required as described in prEN 15882-1. Suspension devices for horizontal ducts

The maximum values for tensile stress and shear stress within the steel suspension devices are as given in prEN 15882-1, Table 5. For unprotected hangers with a length more than 1.5m, precautions must be taken to prevent the extension of the hangers exceeding 40mm. Guidance is also given with regard to the fixing and positioning of the suspension devices. The bending stress in the horizontal load-bearing member of the suspension device shall not exceed that tested. Acc ess pan els

If access panels are to be fitted to the duct system then an access panel of the same design must be tested as described in BS EN 1366-1. Construct ion details and parameters that may affect the fire resistance perform ance of ducts

Construction details and parameters that may affect the fire resistance performance of ducts are listed in Table 4 of prEN 15882-1. The table includes the likely influence of these factors on the performance criteria and includes rules stating whether or not the factors will adversely affect the fire resistance performance and whether additional tests are necessary. Factors included in the table are: • • • • • • •

Orientation – Vertical or horizontal Fire exposure – Fire outside or inside Presence of combustible materials within duct Changes in negative pressure Positive pressure Change in shape (e.g. rectangular to circular) Pieces of ductwork for change of direction or cross section or for separation of air streams


39


• • • • • • • • • • • • • • • • • • • •

• • •

Height of cross section Width of cross section Thickness of protection Length of duct between flanges/spigot Distance between board joints Change in wall/floor type or thickness Change in diameter of cross section for circular ducts Change of protection material Distance between stiffeners Number of protective layers Changes in penetration seal system around duct Effect of access panels Hangers – Changes in length, tensile stress, position relative to any duct joint Bearers – Bending stress, shear stress, section modulus Anchors – Type of anchor, chemical or mechanical, strength, penetration depth Self-weight of duct Hanger protection Length of vertical ducts between supports Effect of supports on vertical ducts Steel duct properties – Galvanised to stainless steel, stainless to galvanised steel, flange to spigot, spigot to flange Mechanical fixings – Screws to staples, staples to screws Inclined/sloping ducts Corner joint details – Changes in arrangement of corner joints for ducts constructed with boards

See prEN 15882-1 for more detailed explanations.

APPENDIX A3: Explanatory notes for the rules of direct field of application of test data (DIAP) for ducts tested to BS EN 1366-8 A.3.1

Int ro du ct io n



The following provides a brief description of the principles behind the rules for the direct field of application of test results. The method of test is only appropriate to fire resisting ducts that have passed the test for the appropriate period to BS EN 1366-1 (ducts A and B). For duct A, it is a requirement for fire resisting smoke extraction ducts that the document under pressure of 300Pa, as given in BS EN 1366-1, is increased to 500Pa when testing to EN 1366-1. For full details refer to BS EN 1366-8, Section 13. Shape of duct s

The field of direct application only covers ducts tested to BS EN 1366-1, ducts A (500Pa under-pressure) and B, and BS EN 1366-8. No extrapolation to one, two or three sided ducts is permitted. Vertical and horizontal duct s

A test result obtained for horizontal smoke extraction ducts is only applicable to horizontal smoke extraction ducts unless vertical ducts are made to the same design and vertical ducts A and B have been tested to BS EN 1366-1 without failure. Sizes of duct s

Provided that the standard sizes of duct are tested, as detailed within the test standard, a limited extrapolation is permitted for larger sizes of duct. Ducts smaller than those tested are also covered. Pressure diff erence

Up to a value of 500Pa the maximum tested under pressure in duct C is applicable to the same maximum overpressure. Above 500Pa, up to 1500Pa, the maximum tested under pressure in duct C is applicable to a maximum overpressure of 500Pa. If higher values are possible then additional testing may be needed. Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

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APPENDIX A4: Explanatory notes for the rules of extended field of application of test data (EXAP) according to EN 15882-8, for ducts tested to BS EN 1366-8 A.4.1

INTRODUCTION


OVERVIEW OF THE CRITICAL PARAMETERS

The following text provides a brief description of the principles behind the rules for the extended field of application of test results. For full details refer to BS EN 15882-8

APPENDIX A5: Explanatory notes for the rules of direct field of application of test data (DIAP) for ducts tested to EN 1366-9 A.5.1

Int ro du ct io n



The following provides a brief description of the principles behind the rules for the direct field of application of test results. The method of test is only appropriate to smoke extraction ducts that do not pass through into other fire compartments. It represents fire exposure of a developing fire (pre-flashover). For full details refer to BS EN 1366-9, Section 13. Shape of duc ts

The field of direct application only covers circular and four-sided rectangular ducts. No extrapolation to one, two or three sided ducts is permitted. Vertical and horizont al ducts

Test is designed for horizontal ducts only. Sizes of du cts

Provided that the standard sizes of duct are tested, as detailed within the test standard, a limited extrapolation is permitted for larger sizes of duct. Ducts smaller than those tested are also covered. Pressure diff erence

Up to a value of 500Pa the maximum tested under pressure in duct C is applicable to the same maximum overpressure. Above 500Pa, up to 1500Pa, the maximum tested under pressure in duct C is applicable to a maximum overpressure of 500Pa. If higher values are possible then additional testing may be needed.

APPENDIX A6: Explanatory notes for the rules of extended field of application of test data (EXAP) according to EN 15882-8, for ducts tested to EN 1366-9 A.6.1

INTRODUCTION


Over vi ew o f t he c ri ti cal par amet ers fo r ex ten ded fi eld of app li cat io n, EXAP

The following provides a brief description of the principles behind the rules for the extended field of application of test results. For full details refer to BS EN 15882-8.


41


APPENDIX B: Explanatory guidance for the use of fire stopping as penetration seals, support systems & ancillary items B.1

PENETRATION SEALS

Where ductwork passes through a compartment wall or floor it must be ensured that the fire separation of the wall or floor is maintained. This is usually achieved in one of two ways:

i)

ii)

For fire resisting ductwork a penetration seal is fitted between the duct and the wall or floor. The penetration seal and the ductwork are considered as one integral system and for the field of direct application must be the same as that tested or assessed in accordance with BS 476: Part 24. For non-fire resisting ductwork a fire damper must be fitted in the plane of the wall or floor. The damper and associated penetration seal must be installed to a procedure substantiated by test. Note that the damper must be mounted in the wall or floor and must be supported/ restrained independently of the ductwork.

Where fire resisting ductwork adjoins a damper fitted in a wall or floor the penetration seal to the wall or floor must be installed as (ii) above. The primary reason for providing fire-resisting ductwork systems is to maintain the fireresistance of a compartment wall or floor of a building. It is therefore critical that the correct method of sealing any gaps around the ductwork is used as it passes through any compartment wall or floor. This detail is one of the most common reasons for the failure of the ductwork system in a fire resistance test. The fire resistance test for ducts (BS EN 1366) is designed to evaluate the fire performance of the duct penetration seal system through a wall or floor construction (the fire separating element), as well as the fire performance of the duct system itself. The purpose of the penetration seal system is to seal the gap between the duct walls and the surrounding wall or floor. In a fire situation, an integrity failure of the penetration seal system is often caused by the movement or distortion of the duct. Therefore it is not possible to separate the fire performance of the penetration seal from the construction of the duct. A successful test on a penetration seal fitted around one type of duct construction does not mean that the penetration seal is suitable for use with a different type of duct construction. Similar comments apply for duct sizes other than that tested. Usually the penetration seal will be suitable for duct sizes sm aller than that tested, but the construction of the duct may have to be modified or the duct locally strengthened at the penetration, for duct sizes larger than that tested. Most of the fire tests on duct penetration seal systems have been carried out through concrete floors or masonry/concrete walls. If the fire separating element is of a different type of construction from that tested, for example a timber floor or a fire rated partition system, then an indicative fire test and an assessment should be carried out to ensure that the duct penetration seal system and/or any damper restraint system is compatible with the different fire separating element for the required fire rating. The EN 1366 fire tests on ducts are carried out on specimens in the horizontal orientation and in the vertical orientation. The fire performance of the penetration seal system must be demonstrated for the orientation in which the duct is being used, or have been assessed as being suitable. If the penetration seal system fails to satisfy the test criteria during the test then the duct or damper system is also deemed to have failed. The perform ance of the system will depend on several factors as follow s: B.1.1

Thermal expansion or shrin kage of ductw ork system

Systems based on steel ductwork will expand in f ire, and self-supporting systems may shrink. This movement may dislodge the seal. B.1.2

Deformation of ductw ork

The sides of any ductwork system are likely to deform in fire conditions. In particular, the top horizontal face of horizontal ducts will tend to sag, causing gaps to form at the seal. The extent of any deformation will depend on a) the size of the duct, b) the materials used to form the ductwork, c) the location of any joints or stiffeners in the system within, or close to, the wall or floor, d) the location of any internal stiffeners within, or close to, the wall or floor, e) the size of any stiffeners and f) the position and size of the hangers on both sides of the wall. B.1.3

Gap size

The size of the gap between the duct and the wall or the floor will affect the performance of the seal. Generally, the bigger the gap, the more likely a failure is to occur. However, if gaps have been sealed Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

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with intumescing materials, a reduction in the gap size may have an adverse effect, as the amount of intumescing material in the gap m ay be inadequate to allow effective expansion, or to seal any increase in the gap size during a fire. B.1.4

Collars

Several ductwork systems employ collars fitted around the ductwork on each side of the wall or floor as part of the penetration sealing system. The collars used in the fire test may have been fixed to the ductwork, or to the wall or floor, or to both. The collars should be fixed as tested. The size of the collar should be adequate to overlap the wall, partition, or floor to at least the same extent as tested. Generally, it is not advisable to fix the collar to both the ductwork and a non-load bearing partition as the thermal movement of the ductwork may have an adverse effect on the performance of the partition. B.1.5

Surround ing const ructi on

The performance of the seal will depend on the type and depth of the wall, partition, or f loor. Generally, the surrounding construction must have at least the same fire resistance as the construction used in the test, and can be thicker, denser, or have more layers of board, as appropriate. The performance of the seal may vary depending on the type of surr ounding construction it is passing through. For example, if the ductwork has been tested passing through a concrete wall, its performance may be different when passing through a lightweight partition system. B.1.6

Specification of seal

The specification of the seal fitted to the duct at the penetrations through fire compartment walls and floors should be the same as the tested system. B.2

SUPPORT SYSTEMS

The support systems used for fire resisting ductwork must be capable of bearing the load of the ductwork under fire conditions. The support system consists of the hangers and bearers, the fixings and brackets. Attention must be given to the spacing of the supports and the size of the support components in accordance with the manufacturer’s test data and recommendations. For the required fire rating, do not exceed – 

The maximum allowable span of the duct between supports



the maximum distance of the hangers from the side of the duct



the maximum allowable stress within the components of the supports

The fixings should be carefully selected for the substrate and loading. They should be non-combustible and/or shown by test to be suitable for the fire rating conditions Stresses within the support components can be reduced by increasing the size of the components, or reducing the spacing of the supports, or applying fire protection to the support systems. 



B.3

If supports were positioned at all duct joints within the furnace in the fire test then the supports must be located at all duct joints in practice. The element of building construction to which the support systems are attached must have a fire rating of at least that specified for the duct and be able to support the weight of the duct under fire conditions. ANCILLARY ITEMS / IN-LINE EQUIPMENT

A fire rated duct will often adjoin a component or structure which does not form part of the tested ductwork system, and could have in-line equipment and control devices such as balancing dampers, filters, attenuators, fans, etc. The performance characteristics of the fire-rated duct must be continued through these ancillary items of equipment to ensure the fire resistance of the system is maintained. Fire Dampers

It is not recommended for fire resisting ductwork to be randomly used to rectify incorrect installation or positioning of dampers (e.g. in situations where a damper tested only for installation in the plane of a wall or floor has been installed remote from a wall or floor). It may be possible to protect the duct on both sides of the wall – up to the damper – to ensure that fire compartment is maintained, and that the fire damper can operate as intended., provided that a positive independent assessment has been car ried out

B.4

INTERFACE BETWEEN FIRE RESISTING DUCTWORK & ELEMENTS OF CONSTRUCTION

Responsibility for the satisfactory performance of each element of building construction (e.g. walls, floors, cavity barriers, etc.) lies with the installer of each particular element. The ‘change over’ of responsibility occurs at the interface between the fire resisting ductwork and the elements. It is imperative that the interface detail does not compromise the fire performance of either the element of building construction or the fire rated duct. Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

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The building designer, mechanical services designer and the installer all have a responsibility to pay ‘due care’ to this detail.

APPENDIX C: Limitations of fire resisting ductwork systems General

This list sets out the principal limitations in the scope of the guidance given in this publication and is not intended to be exhaustive. a)

The term Fire resisting ductwork is deemed to refer to a system as tested or assessed in accordance with BS EN 1366-1. As the vast majority of tests on steel ducts are conducted with rigid ducts it is not appropriate to extrapolate this data for flexible steel ducts. Therefore, unless the flexible steel duct system has been tested in accordance with BS EN 1366-1, this guidance cannot be assumed to apply.

b)

Service ducts are not included within this guidance.

c)

Fire resisting ductwork systems shall be deemed to include all the components as tested or assessed, including supporting systems and penetration seals. Reference is made to the Field of Application section within this guidance.

d)

The element of building construction to which the support systems are attached must have a fire rating of at least that specified for the duct and be able to support the weight of the duct under fire conditions.

e)

Fire resistance of a fire resisting ductwork system shall be expressed as the three time period components - stability, integrity and insulation. Where only a single time period is expressed it shall be deemed to apply to all three components, unless clearly defined otherwise. (e.g. 90 minutes, stability & integrity only).

f)

It is essential when choosing a fire rated duct system that it is fit for the purpose to which it is being applied. Considerations other than the successful completion of a BS EN 1366-1 fire test on a sample section of ductwork may need to be given when assessing the suitability of a fire rated duct for a particular application.

g)

During any defined non-fire operating conditions, fire resisting ductwork must be capable of both performing and being tested to the ductwork classification and the air leakage limits of the designated ductwork specification, e.g. DW /144.

h)

In general, the air flow characteristics of ductwork and its associated components such as bends, branches and changes of section must all be in accordance with DW /144 and CIBSE Technical Memoranda TM8, Design Notes for Ductwork.

i)

In the case of an existing metal duct , where application of a fire insulation cladding material to provide fire resistance is considered, it is imperative that the construction standard of the metal duct is checked for conformity with the appropriate fire test report. Similarly, the construction of a newly erected metal duct should be the subject of like scrutiny. Metal gauge, spacing & size of flanges and stiffeners, bolting centres, use of steel / aluminium rivets, sealants, spacing of hanger supports and fixing method to the soffit should all be checked for compliance with the fire tested construction. It is not sufficient to rely on a DW/144 construction classification for fitness for purpose in this regard.

j)

For the purposes of independent assessment, laboratories accredited by UKAS for conducting the relevant test might be expected to have the necessary expertise.

k)

It is recommended that the installed fire rated duct system be verified by the use of a quality system, based upon the ISO 9000 Series. This will enable the supplier/installer to provide documentary evidence of the conformity of the installed system and its components. Verification will required and include research, checking or test of existing ductwork installations which are being modified and / or over-cladding to provide a fire r ated system.

l)

Light gauge specifications such as DW/144 recognise many machine forming techniques for ancillary items such as air turning vanes and the increased gauges associated with fire resisting ductwork systems may not only preclude the use of such techniques but may also, out of necessity, introduce a geometric change that may require the approval of the HVAC designer in terms of a component's air flow characteristics.

m)

A fire rated duct tested to BS EN 1366- 1 (Ventilation duct test) which meets criteria of stability, integrity and insulation may not be suitable for kitchen extract application or smoke extract application unless proven by additional test criteria, as outlined in Appendix A


44


n)

For the field of direct application, any penetration seal must be the same as that used in the original BS EN 1366-1 test, see section 6.1

o)

Where fire dampers are connected to a fire rated duct it is assumed by this guidance note that the combined installation is adequate for the required fire resistance. However it is incumbent upon the designers and providers of such damper installations to verify that they have been appropriately tested adopting the procedures and criteria of BS EN 1366-1.

p)

This guidance does not address the complex and detailed issue of fire and/or smoke dampers or any other fire resisting components or elements of structure with which the fire resisting ductwork system interfaces, save for their assumed levels of adequacy. Responsibility is therefore deemed to end with the interface.

q)

Special care must be taken with in-line items of equipment such as fans, volume control dampers, attenuators etc. Where such items are within a fire resisting ductwork run, the item of equipment must maintain the full fire performance of the duct into which it is fitted or it must be installed within its own fire rated enclosure (same performance as the duct). Access provisions to the ductwork for cleaning and maintenance should also maintain the fire performance of the duct to which they are fitted.

r)

The expansion of the ductwork could cause excessive forces on an associated wall or floor construction and penetration seals, which, could result in their failure under fire conditions. The ductwork route should either be reconsidered, to lessen the effect of expansion on the penetration seals, or fire resisting expansion devices/compensators should be included within the ductwork.

APPENDIX D: Regulations, codes and requirements D.1

INTRODUCTION TO REGULAT IONS

Fire protection is intended to preserve life and property. Effective fire retardant products and systems play a critical role in restricting the spread of flame and in reducing the rate of heat release from surfaces and thereby help limit the contribution that that the fabric of the building makes to the fire growth. In very simple terms, building work in the United Kingdom is regulated in the following manner: •

UK Parliament produces Statutes (Acts of Parliament), edicts of the legislature.

•

Modern Acts contain provisions which authorise others, office-holders or Bodies (e.g., a Secretary of State), to make regulations on particular subjects within the scope of application of an Act.

•

Finally, official bodies, such as departments of state, may publish approved documents which may either (a) give advice about compliance with an Act or Regulations, or (b) cite other sources of relevant information (such as British Standards).

D.2

BUILDING REGULATION IN THE UNITED KINGDOM

D.2.1

England and Wales

There are two principal branches of building legislation and fire safety in England and Wales. •

Building control is affected by the Building Act 1984 and its subsidiary legislation and guidance documents.

It regulates new building work or material alterations to existing buildings. • D.2.2

Requirements to establish and maintain fire safety in buildings in use are contained in the Regulatory Reform (Fire Safety) Order 2005 (clause 5.3)

Bui ldi ng Act 1984

The Building Act consolidated much of the primary legislation relating to building which then existed in other Acts of Parliament. Much of the Act is concerned with building regulations and related matters. The current Building Regulations are the descendants of a long line of Statutory Instruments on the topic and the 2000 version (The Statutory Instrument Building Regulations 2000 (SI 2000, No. 2531)) has been amended several times since first issued. The Building Regulations present the requirements which must be complied with, in terms of design and construction, broadly to ensure the health and safety of those who occupy or visit buildings. Approved Documents exist in support of the Building Regulations and are issued by the Secretary of State, and are aimed at providing guidance for those seeking to meet the requirements of the Building Regulations in a prescriptive manner.


45


D.2.3

Scotland

In Scotland there is a similar divide, the relevant legislation is the Building (Scotland) Regulations 2004 (Scottish Statutory Instrument 2004 No. 406), for new buildings of alterations and the Fire (Scotland) Act 2005 for existing buildings. Guidance on achieving the standards set in the Building Regulations is contained in the Scottish Technical Handbooks (revised in May 2007), which are available in two volumes, dealing with Domestic and Non-domestic buildings. The Handbooks are available to view online or download in full or part in PDF format via http://www.sbsa.gov.uk/tech_handbooks/tbooks2009.htm#1 D.2.4

North ern Ireland

In Northern Ireland, the controlling legislation is the Building Regulations (Northern Ireland) 2000 (Statutory Rule 2000 No. 389, as amended). Building control matters are the responsibility of the Department of Finance and Personnel, which produces a series of Technical Booklets to aid compliance with the Regulations. Technical Booklet E covers fire safety: for more information go to www.dfpni.gov.uk and search successively for Building Regulations and Technical Booklets. D.2.5

Isle of Man

In the Isle of Man building control operates via the Manx Government’s Building Regulations 2003, Statutory Document No. 829/03, made under the Island’s Building Control Act 1991. D.2.6

Channel Islands

The procedure for building control varies across the islands but is broadly similar to the system in England and Wales, comprising an item of subsidiary legislation supported by a set of technical guidance publications. They are Regulations in Guernsey, but Byelaws in Jersey. NOTES

1.

For new buildings, buildings which are changing their use, and for extensions or alterations to existing buildings, reference should be made to the guidance given in the above mentioned documents.

2.

For commercial and industrial buildings, property and business insurance may also be an important consideration. Useful information can be found in the FPA Design Guide for the Fire Protection of Buildings or go to www.thefpa.co.uk

D.3

FIRE SAFETY LEGISLATION FOR EXISTING BUILDINGS

D.3.1

Regulator y Reform (Fire Safety) Order 2005

The UK Government carried out a major review of many existing pieces of legislation relating to fire safety, the main aim being to arrive at a single, simplified fire safety regime which would have general application across workplaces and non-domestic premises. The result was the Regulatory Reform (Fire Safety) Order 2005, which came into effect on 1 October 2006 and applies in England and Wales. It covers ‘general fire precautions’ and other fire safety duties needed to protect ‘relevant persons’ in case of fire in and ar ound most ‘premises’. The Order requires fire precautions to be put in place where necessary and to the extent that it is reasonable and practicable in the circumstances of the case. The new system of regulation is risk-assessment based and includes the provision that the person responsible for a building should undertake duties for fire safety therein. Risk assessment is a vital part of the planning process and is dealt with below. Experienced designers will know all about the Building Regulations as they apply to domestic or other types of buildings. They may only just be finding out about the possible ef fects of the Regulatory Reform Order. It is a Statutory Instrument which repeals a great deal of existing fire safety legislation and while a full account of its provisions is beyond the scope of this publication the text of the Order is available at www.opsi.gov.uk (the website of the Office of Public Sector Information), (‘SI 2005 No 1541’). The Department for Communities and Local Government (CLG) has published a series of guides which introduce employers, managers, occupiers and owners to the new fire safety regime as it affects a variety of types of premises, under the generic title ‘Fire safety risk assessment’ While the Order is principally an item of secondary legislation dealing with responsibilities for and pr acticalities of implementing fire safety in workplaces (and some parts of blocks of flats and of houses in multiple occupation), designers may find that the Order brings them on board much earlier in the process, at the stage of considering fire risk assessments for new workplaces or major alterations of existing premises. Approved Document B indicates that a preliminary risk assessment can be used as part of a Building Regulations submission and can help identify if any additional features need to be c onsidered with respect to the f irst occupation of a building. The local fire and rescue authority is the enforcing authority for the provisions of the Order. Guidance on the consultation procedures that should be adopted to ensure that the requirements of all enforcing authorities are addressed at the stage of Building Regulations approval is given in the publication Building Regulation and Fire Safety: Procedural Guidance (published jointly by CLG and the Welsh Assembly Government) Fire Resisting Ductwork European version 1st Edition Association for Specialist Fire Protection

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Supporting Documents The following supporting documents may be useful, but is not an exhaustive list

• •

11 new Risk Assessment Guides for buildings in different types of occupation Department of Health HTM 05 Series, including - HTM 05-01 Managing Healthcare fire safety - HTM 05-02A Guidance in support of functional requirements - HTM 05-02B Fire engineering provisions - HTM 05-03 Operational provisions

•

A new publication from the Department for Children, Schools and Families entitled Building Bulletin 100 – Designing & managing against the risk of fire in schools. [replaced BB 7 - Fire and the design of educational buildings (DES) 1988]

D.3.2

Fire (Scotland ) Act 2005

In Scotland, Part 3 of the Fire (Scotland) Act 2005 - and related subordinate legislation – also introduced a new st fire safety regime on 1 October 2006. This legislation is also based on the ongoing fire safety risk assessment of buildings. Similar changes are expected in Northern Ireland. In all cases, this means that Fire Certificates will be abolished and an existing f ire certificate will no longer have eff ect. The responsibility will be with allthose having any degree of control over nearly all non-domestic pr emises, along with Houses in Multiple Occupation D.3.3

• • • D.4

Government sources of furth er infor mation

www.planningportal.gov.uk www.infoscotland.com/firelaw and http://www.dfpni.gov.uk/index/buildings-energy-efficiency-buildings/building-regulations/br-technicalbooklets.htm CONSTRUCTION DESIGN AND MANAGEMENT REGULAT IONS 2007

The Construction Design and Management Regulations (CDM) require all concerned in the process from design inception to completion of the building to prepare a file (the CDM file) containing details of all the work undertaken and materials used where safety is concerned. The CDM file can be an invaluable source of information on all aspects of fire safety work in the construction of the building that may be used by the occupant when preparing maintenance plans, modifications to the building or Fire Risk Assessments as required by the Fire Precautions (Workplace) Regulations. The relevant web page is http://www.hse.gov.uk/construction/cdm/summary.htm D5

OTHER DOCUMENTS

London District Surveyors Association Fire Safety Guide No 1 - Section 20 Buildings: 1997 Fire Prevention Association FPA Design Guide for the Fire Protection of Buildings, together with other publications on behalf of the RISCAuthority insurance organisation www.thefpa.co.uk/publications. See www.thefpa.co.uk

APPENDIX E: Bibliography E.1

BRITISH STANDARDS

BS 476: Fire Tests on Build ing Materials and Struct ures

Part 4:

1970 1984

Non-combustibility test for materials Non-combustibility test for materials

Part 6:

1981 1989

Method of test for fire propagation for products Method of test for fire propagation for products

Part 7:

1971 1987 1997

Surface spread of flame test for materials Method for classification of the surface spread of flame of products Method of test to determine the classification of the surface spread of flame of products

Part 11: 1982 1988

Method for assessing the heat emission from building materials Method for assessing the heat emission from building materials

Part 20: 1987

Method for determination of the fire resistance of Elements of construction (general principles)


47


Part 21: 1987

Methods for determination of the fire resistance of load bearing elements of construction

Part 22: 1987

Methods for determination of the fire resistance of non-load bearing elements of construction

Part 23: 1987

Methods for determination of the contribution of components to the fire resistance of a structure

Part 24: 1987

Method for determination of the fire resistance of ventilation ducts (ISO 6944)

BS 5669 for impact test information BS 7346 Components for smoke and heat control systems; Part 2: 1990 Specification for powered smoke and heat exhaust ventilators

E.2

E.3

BS 8313: 1989

Code of practice for accommodation of building services in ducts.

BS ISO 10294

Fire Resistance tests - Fire dampers for air distribution systems Part 1: 1996 - Test method. Part 2: 1999 – Classification, criteria & field of application of test results Part 3: 1999 – Guidance on the test method Part 4: 2001 – Test of thermal release mechanism Part 5: 2005 – Intumescent fire dampers

ISO STANDARDS (Internatio nal Organis ation for Standardi satio n)

ISO 834:

Fire resistance tests – Elements of building construction

ISO 834-1:1999

Fire resistance tests – Elements of building construction: Part 1 General requirements

ISO 6944-1

Fire Resistance Tests – Elements of building construction: Part 1 Ventilation ducts

ISO 6944-2

Fire resistance tests – Elements of building construction: Part 2 Kitchen extract ducts

ISO 9000: 2000

Quality management systems – Fundamentals and vocabulary

IS0 9001: 2000

Quality management systems – Requirements

EUROPEAN STANDARDS (CEN)

BS EN 1366

Fire resistance tests for service installation -

BS EN 1366-1: 1999 Part 1 - Ducts BS EN 1366-2: 1999 Part 2 - Fire dampers BS EN 1366-3

Part 3 - Penetration seals

BS EN 1366-4

Part 4 - Linear joint seals

BS EN 1366-5

Part 5 - Service ducts and shafts

BS EN 1366-8

Part 8 - Multi compartment smoke extraction ducts

BS EN 1366-9

Part 9 - Single compartment smoke extraction ducts

BS EN 1366-10

Part 10 - Smoke control dampers

BS EN 13501:

Fire classification of construction products and building elements: Part 1: Classification using data from reaction to fire tests Part 2: Classification using data fr om fire resistance tests, excluding ventilation services Part 3: Classification using data from fire resistance tests on products and elements used in building service installations: fire resisting ducts and fire dampers Part 4: Classification using data from fire resistance test on components of smoke control systems

BS EN 12101-7

Smoke and heat control systems Part 7: Smoke control ducts

BS EN 15882-1

EXAP rules for fire resisting ducts tested to EN 1366-1


48


BS EN 15882-8 E.4

EXAP rules for fire resisting ducts tested to EN 1366-8 or EN 1366-9

HVCA DOCUMENTS

DW/143: 2000

A practical guide to ductwork leakage testing

DW/144: 1998

Specification for sheet metal ductwork; low medium and high pressure velocity systems (supersedes DW/142)

DW/145:2008

Guide to good practice for the installation of fire and smoke dampers

DW/172: 2005

Standard for kitchen ventilation systems

TR/19: 2005

HVCA Guide to good practice – Internal cleanliness of ventilations systems

APPENDIX F: Standard specifications & method of measurement of building works F.1 STANDARD METHOD OF MEASUREMENT OF BUIL DING WORKS

The measurement of fire resisting ductwork should f ollow the guidelines of Tables Y30 and Y31 of SMM7 th [Standard method of measurement - 7 Edition: 2000] as published by the Royal Institution of Chartered Surveyors, ISBN 08540 63609. It is essential that any bill of quantities description f or fire resisting ductwork includes ALL of the following.This is a minimum list for fire assessments to be reliably made . 



Duct function – ventilating, smoke extract or kitchen extract Duct type – self supporting construction, factory made fire resisting duct, or fire protection cladding added to specified steel ducts



Duct orientation – horizontal or vertical



Duct size – longer side or diameter



Thickness of steel, board and/or coating



Duct shape



Any stiffening of the duct panel



Any stiffening of the duct , the type and maximum spacing



Any use of internal duct stiffeners or tie rods



Maximum duct section length



Type, shape and size of cross joints



Maximum spacing for hangers and bearers



Any required fire protection layers or insulation – with material, thickness and fixings





Fire resistance requirement - e.g., 60 minutes stability, 60 minutes integrity and 60 minutes insulation when tested in accordance with EN 1366) The detail of the seal at any service penetration through compartment walls, floors or fire resisting division.

NOTE that fire resisting ductwork must be measured as a complete item in linear metres with ancillaries and fittings described and measured separately. F.2

STANDARD SPECIFICATION

In order to ensure fire resisting ductwork is correctly specified prior to the commencement of work, several factors should be carefully considered and defined. The Specification should therefore: 1)

Define the type of ductwork, as - Smoke / Ventilation / Kitchen / Pressurisation

2)

State the required fire classification to EN 13501-2 in minutes for:

3)

i)

Integrity E

ii)

Insulation I

iii)

Leakage S

Define if the system is Duct Type A (fire outside) or Duct B (fire inside) or requirement for both ’fire inside’ and ‘fire outside’.


49


4)

Define Static Pressure Limits – Pressure / velocity

Class

Low

Pressure level range Positive pressure

Negative pressure

Class A

Up to + 500 Pa

Down to - 500 Pa

Medium

Class B

Up to + 1000 Pa

Down to - 750 Pa

High

Class C

Up to + 2000 Pa

Down to - 750 Pa

High

Class D

Up to + 2500 Pa

Down to - 750 Pa

NOTE that these classifications are to HVCA DW /143 and 144 requirements 5)

The Fire Duct manufacturer should define the friction resistant coefficients of all bends and tapers, etc. which are to be used if they differ from those for galvanised sheet steel.

6)

It is recommended that the manufacturer/installer is working to a Quality Assurance System based upon the ISO 9000 series. With reference to the above factors, the standard Specification should read: ‘The ___(1)___ Ductwork should be constructed in accordance with the ASFP Guide to Fire Resisting Ductwork to provide __(2)i )__ minutes stability, __(2)ii )__ minutes integrity, and __(2)ii i )__ minutes insulation when tested to the requirements of EN 1366 by a UKAS approved or recognised laboratory. The ductwork should be capable of providing Type ___(3)___ fire containment and, under normal non-fire operating conditions, should conform to the ___(4)___ pressure classification of the current HVCA DW/144 Specification for Sheet Metal Ductwork.’

APPENDIX G: Criteria of acceptability of data sheet entries LEVEL OF ENTRY st

The ASFP ‘Blue Book – European version 1 Edition’ makes provision for data sheets based on BS EN fire test and classification methods, which replace BS 476 Part 24 fire test data for use in regard to European Construction Products Directive. rd

For acceptance in this ASFP publication, the data is all subject to 3 party product certification as a basic condition of entry. See Rules 1 to 5 as stated below. GENERAL

These rules supplement the procedure for ASFP members to submit product data sheet entries for inclusion in ASFP Publications, as provided in ASFP document TCOM 08_17. rd

The claims in the product data sheets will be confirmed by the 3 party Certification Body. The claims made must also satisfy the criteria in Rules 1 to 5 as listed below, and as Section 1 ‘Scope’ of this publication. All claims will be based on EN Fire Resistance classification and test methods, to enable specific UK Regulatory requirements to be satisfied. It should be noted that, at the time of writing, the proposed European Community’s Construction Products Regulation, the CPR, may demand mandatory compliance with BS EN standards around mid 2011. When that happens, BS 476 Part 24 test data will only be applicable for non- CPR applications for construction products.

RULE 1 – PRIMARY DATA

[a] Submissions for data entry into the ASFP ‘Blue Book’ for fire resisting ductwork shall be made in accordance with BS EN 13501 Parts 3 and 4 classification standards for [i] fire resisting ducts and for [ii] smoke control ducts respectively. The classification documents call up BS EN1366-1 for fire resisting ducts, BS EN1366-8 f or multi-compartment smoke ducts, or BS EN1366-9 for single compartment smoke ducts. [b] Entries into the ASFP data sheets may also be produced from test data and classification documents using published draft European standards (prEN). If the draft standard is significantly changed, then the classification may need to be withdrawn by the Notified Body and Certification Body as advised by CEN TC127.It should be noted that all standard documents are reviewed on a regular basis, 5 years, and subject to amendment without withdrawal of the original classification document [c] Test data for BS EN1366-1 must be available before any test data is obtained on the same system to BS EN1366-8, in order that a classification document can be issued, and considered for use in this ASFP publication.


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RULE 2 – SECONDARY DATA

Rules for direct or extended fields of application will state whether or not national or historical test data can be used for classification purposes. RULE 3 – DIRECT AND EXTENDED FIELDS OF APPLICATION

The field of application for the classification obtained from test data can fall into two cases, direct or extended fields of application. The rules for direct field of application are provided in the test standard. Rules for extended application are given in EN 15882-1 for ducts, and in EN 15882 – 8 for smoke control ducts. The classification report will provide the agreed scope of application RULE 4 – 3

RD

PARTY PRODUCT CERTIFICATION SCHEMES

For inclusion in this publication, fire resisting products must have been tested to the satisfaction of independent rd accredited 3 party product certification schemes (ISO Guide 65) covering the test data required in Rule 1 and recognised by the UK Accreditation Service, UKAS (accredited to ISO 17025). W here fire resisting ducts are listed by such a Certification Body, then they will be deemed acceptable for entry into the ASFP ‘Blue Book’ for fire resisting ductwork data sheets, providing the claims being made are confirmed in writing to the ASFP by the Certification Body. RULE 5 – UNCERTAINTY OF DATA

The ASFP Technical Review Panel reserve the right to review all and any submissions and claims being made for use in ASFP publications.

APPENDIX H: Data Sheets H.1

GUIDANCE TO DUCT SYSTEM DATA SHEETS & CAUTIONARY NOTE

H.1.1

Guidance on the use of system data infor mation

The following product data pages will be extended as new European test data becomes available. They will outline the capabilities of different fire resisting duct arrangements as available from ASFP member companies. Whilst all the data has been independently assessed by 3rd party certification bodies or reviewed by ASFP Technical Review Panel, as defined elsewhere in this document, the ASFP points out, to system specifiers, that there are a very large number of variables that must be considered in selecting or specifying the appropriate system, and in ensuring that the ‘as-built’ system fulfills the claims of the tested system. The specific product literature of system holders should always be referenced to consolidate theinitial selection , and before installation is made. The web links are provided on each descriptive product page to assist this process. The ASFP has ensured that a minimum level of key information is included either in the system Tables or in the Notes accompanying each Table. Some system holders may have elected to include other additional information so as to assist the correct use of the relvant ductwork system. The design of a fire resisting ductwork system is generally dependent on the following factors – 1.

The type of ductwork system as used for ventilation OR smoke extract OR kitchen extract, etc

2.

The fire resistance to EN 1366 in terms of stability, integrity, insulation and leakage in fire

3.

The orientation of the duct in use, either horizontally or vertically or both.

4.

The cross-sectional shape of the ductwork system, as rectangular, or circular, or as flat oval shape

5.

Any requirements or limitations for:a.

The maximum dimensions of the duct cross-section

b.

The type, nature and frequency of duct joints

c.

The need for stiffeners to the panel and duct system, in relation to its geometry, dimensions, orientation in use, and required fire resistance

d.

The type, size and frequency of duct stiffeners

e.

The frequency of cross joints

f.

The frequency of supports - hangers and bearers

g.

The specification of all cross joints or longitudinal joints, including the use of seals or gaskets

6.

Add fire protection to the duct support systems, as required by the fire test data or assessment.

7.

Ensure the use of fixings for hanger systems that are suitable for the applied load, the fire resistance period, and the substrate being fixed to. NOTE that other services must not be supported by the fire tested ductwork system


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Fire Resistant Ductwork - Guidelines

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