2002 fire extinguishing system-guide to their integration with other building services

Fire Extinguishing SystemsA guide to their integration with otherbuilding services

By John Sands

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FIRE EXTINGUISHING SYSTEMS © BSRIA AG 17/2002 25/11/02 FIRE EXTINGUISHING Systems

ACKNOWLEDGEMENTS

BSRIA would like to thank the British Fire Protection Systems Association (BFPSA) and its members for sponsoring this publication, and for providing invaluable technical guidance during its production. Acknowledgement is also given to Faber Maunsell for their assistance in providing technical information. Every opportunity has been taken to incorporate the views of the contributors, but final editorial control of this document rested with BSRIA. BSRIA is grateful for the use of photographs and illustrations in this document. The use of such images does not in any way imply product endorsement by BSRIA.

The BFPSA has been at the forefront of developments in the fire protection industry since its formation in 1966. The Association represents manufacturers, installers and maintainers of fire alarm and fixed extinguishing systems, with membership representing an estimated 95% of the UK’s purchases in this important sector of the market. The BFPSA has an ongoing role assisting in the development of the standards and regulations which have helped to ensure that the UK has one of the best fire safety records in the world. In the European arena, the BFPSA represents the interests of the UK fire protection industry through its active participation in Euralarm and Eurofeu. The Association also has a very active training programme, offering a wide range of courses providing knowledge which has a real and practical application in the workplace. For details of training courses by the BFPSA please turn to the end of this document. Further details on the work of the BFPSA are available from the secretariat: BFPSA, Neville House, 55, Eden Street, Kingston Upon Thames, Surrey KT1 1BW Tel: 020 8549 5855 Fax: 020 8547 1564 Website: www.bfpsa.org.uk

©BSRIA 16511 November 2002 ISBN 0 86022 608 5 Printed by The Chameleon Press Ltd.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means electronic or mechanical including photocopying, recording or otherwise without prior written permission of the publisher.

FIRE EXTINGUISHING SYSTEMS © BSRIA AG 17/2002 13/11/02 FIRE EXTINGUISHING Systems

CONTENTS

1 INTRODUCTION 1 1.1 The purpose of this guide 1 1.2 The format of this guide 1

2 FIRE EXTINGUISHING SYSTEMS 4

2.1 General 4 2.2 Design 8 2.3 Extinguishants 14

3 STANDARDS 19

4 DESIGN CONSIDERATIONS 21

4.1 General 21 4.2 Programming 21 4.3 Procurement 21 4.4 Exchange of information 22 4.5 Air conditioning systems 23 4.6 Ventilation systems 25 4.7 Power supplies 29 4.8 Controls 30 4.9 Other fire detection and alarm systems 30 4.10 Access control/security systems 31 4.11 Builders work requirements 31

5 INSTALLATION CONSIDERATIONS 33

5.1 General 33 5.2 Programming 33 5.3 Exchange of information 33 5.4 Site supervision 34 5.5 Air conditioning systems 34 5.6 Ventilation systems 35 5.7 Power supplies 35 5.8 Controls 35 5.9 Other fire detection and alarm systems 36 5.10 Access control/security systems 36 5.11 Builders work requirements 36 5.12 Operation and maintenance information 37

REFERENCES 39

APPENDIX A 40

APPENDIX B 57

APPENDICES

FIRE EXTINGUISHING SYSTEMS

© BSRIA AG 17/2002

TABLES

Table 1: The number of cylinders required for different system types for typical room volumes 6

Table 2: Commonly used inert gases 15 Table 3: Commonly used halocarbon agents 16 Table 4: Area of pressure relief required for different system

types for typical room volumes 26

Figure 1: A typical fire extinguishing system installation 4 Figure 2: Discharge graph for non-liquiefied extinguishants 11 Figure 3: Discharge graph for liquiefied extinguishants 11 Figure 4: Gas cylinder installation 15 Figure 5: Pressure relief damper with pneumatic actuation 25

FIGURES

INTRODUCTION

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1 INTRODUCTION 1.1 THE PURPOSE OF

THIS GUIDE Welcome to Fire extinguishing systems – a guide to their integration with other building services. This concise document will enable building services designers to quickly familiarise themselves with the key issues of fire extinguishing systems, and how to successfully integrate them into the total services provision for a protected space or area. The guide is also intended to be a general guide for inspectors of fire protection systems to help them to assess the quality of the installation and its functionality with the building and its systems in a systematic and clearly defined manner.

Other building professionals involved in the design and construction process, such as architects, structural engineers, and contractors – both for the building works and the mechanical and electrical services – will also find the publication useful to understand the extinguishing system and its relationship with other aspects of the building.

Fire extinguishing systems are an essential part of many contemporary buildings as they provide fast and effective control of fires in their very early stages, and before any great damage can be caused. They are particularly suitable for use in areas with high levels of electrical and electronic equipment, enabling operations to re-start quickly after discharge of the extinguishing system. This reduces down-time and disruption to a minimum, provided, of course that any fire damage is minimal.

Such systems are generally designed and installed by specialists in line with strict codes and standards. This ensures quick and effective operation in the event of activation. However, regardless of how good the fire extinguishing system may be, to prove truly effective in operation the system must be properly integrated with the rest of the building services systems serving the protected area. The guide will provide the basic information necessary to enable designers and the building team to provide a complete and fully integrated fire extinguishing solution.

1.2 THE FORMAT OF

THIS GUIDE The document is organised in the following sections, which represent the order in which the various issues would normally be addressed by the user.

Fire extinguishing systems This section contains descriptions of the main types of fire extinguishing systems currently in use throughout the UK, and the typical applications for each one. Spinklers have not been included in this document. The systems discussed include: • Halon • Inert gases • Halocarbon agents • Carbon dioxide • Foam • Dry powder • Fine water spray/water mist

INTRODUCTION 1

INTRODUCTION

2 FIRE EXTINGUISHING SYSTEMS

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Standards The standards and guidance documents applicable to fire extinguishing systems are listed on page 19 as an easy source of reference. These standards and regulations apply to particular systems both at the design and installation stages.

Design considerations This section examines the key aspects of the services design process and details the associated co-ordination issues. The most important factor is to ensure that the fire extinguishing system interfaces correctly with other building services systems, and the building structure and fabric. The areas addressed include: • Exchange of information

• Air-conditioning systems

• Ventilation systems

• Power supplies

• Controls

• Fire detection and alarm systems

• Access control/security systems

• Communications

• Builders work requirements

Installation considerations This section follows on from the approach adopted in the section Design Considerations and applies them to the installation process. The best design can fall down if not properly installed. The areas addressed here include: • Exchange of information

• Site supervision

• Air-conditioning systems


• Power supplies

• Controls

• Fire detection and alarm systems

• Access control/security systems

• Communications

• Builders work requirements

INTRODUCTION


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Inspection checklists The inspection checklists have been arranged to cover the complete design and installation process, and to ensure that all concerned parties are aware of what is required of them to provide a satisfactory end product. Checklists provided include: • A project information sheet

• A designer’s checklist (for use by the consulting engineer)

• A fire extinguishing system specialist’s checklist

• A main contractor’s checklist

• Pre-commencement, interim and final inspection checklists

Fax-back response form A fax-back form has been included in Appendix B to give the reader the opportunity to provide feedback on the publication.



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This section deals with the basic principles of fire extinguishing systems, and is intended to provide the reader with a good working knowledge of the technology. Similar issues relating to the associated engineering services are addressed in Section 4.

2.1 GENERAL Basic principles A fire extinguishing system is a type of fire protection that is used to protect a particular hazard, where more conventional forms of fire protection may not be suitable. For example, a large office block may be protected throughout the office areas and corridors by a sprinkler or pre-action sprinkler system. However, the central computer facility may be equipped with a gaseous system as a more appropriate method of fire protection.

Figure 1: A typical fire extinguishing system installation.

Although there are many different types of fire extinguishants for these systems, (as described later in this section), the basic principles of the system remain largely the same. In their most basic form, automatic detectors are located throughout the areas to be protected to sense signs of a fire. The approach of the extinguishing system is to detect a fire via a controls system and extinguish the fire before it has a chance to become established. The detectors initiate the discharge of the extinguishant into the protected space from the storage facility through pipework and nozzles to extinguish the fire. Inert gas systems operate by reducing the oxygen content within the protected area to a level below which there is insufficient oxygen to support combustion. The extinguishant is stored as a gas at pressures of 150-300 bar. Chemical-based systems operate by absorbing the heat and thus reducing the temperature in the protected area and, to a lesser extent, by attacking the combustion chain. In these systems the chemical agent is stored at a lower pressure than inert gases, often with nitrogen added to create a propellant-pressure for discharge. The agent changes state to a gas upon release from the nozzle.




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System components Such a system normally consists of the following two main elements: • Detection, actuation and control • Extinguishant storage and distribution

Detection, actuation and control This element of the system deals with detecting the early signs of a fire and processing the action to be taken by the rest of the system. The detection of fire is achieved by detectors located throughout each protected area, linked electrically to the control panel or unit. In a typical computer-room application with floor and ceiling voids, detectors may be provided to give protection for each of these areas. Both optical and ionisation detectors will be used, with each area zoned to provide first and second stage operation. Coincidence operation of detection zones helps to prevent inadvertent discharges. More information on coincident operation can be found in BS 72731. Control units should be mounted outside the protected space, and incorporate a switching facility to allow users to select the mode of operation of the system – automatic or manual. When the protected space is occupied, the system may be set to manual to avoid discharge with people in the space as described in BS ISO 145202. With the system switched to manual, the occupants have the opportunity to investigate the source of the fire without risk of the extinguishant discharging. In the case of a false alarm, or a small fire that could be dealt with successfully and safely with hand-held extinguishers, this could save unnecessary discharge of extinguishant. However, in a fire emergency, such action places a special responsibility on management to remember to switch the option back to automatic or to actuate the system. The system should be set to automatic operation whenever the room is not occupied.

Extinguishant storage and distribution The second main element of the system is the storage and distribution of the fire extinguishant. This is contained under pressure in cylinders or containers connected by pipework. A pipework network or system then runs to discharge nozzles located within each protected area or zone. The cylinders should ideally be mounted outside the protected zone to allow access for maintenance and testing without needing to gain access to the protected area itself. For large installations, the number of cylinders required can be considerable. Space needs to be found to house them, and the area also needs to be strong enough to support their weight. However, the number of cylinders required for a particular application will vary greatly depending on the extinguishant used, with inert gas systems typically requiring more than chemical agent systems. This is demonstrated in Table 1 and gives an approximation of the number of inert gas cylinders required for a range of room sizes, covering the three possible system storage pressures.



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Note that the figures contained here are for general guidance only, and are intended for use at the early stages of a project to help determine spatial allocation for cylinders. Average or typical size cylinders have been used, and the numbers shown can vary if other sizes are used. Cylinder quantities may also vary slightly between manufacturers. The table must not be used for detailed design purposes; the designer should discuss the exact system requirements with the fire system specialist as soon as possible in the project design process in order to determine the exact quantities that are required.

Table 1: The number of cylinders required for different system types for typical room volumes.

Room volume in cubic metres

System type 50 100 150 200 250 300 350 400 450 500

Inert gas 2 4 5 7 9 10 12 13 15 16

Chemical 1 1 1 1 1 2 2 2 2 2

CO2 2 4 5 7 9 10 12 14 15 17

Reduced storage space is a clear benefit of chemical agents and Table 1 provides a comparison based on the quantity of cylinders for inert gas, a typical chemical agent and CO2

against a range of protected volumes. However, it should be recognised that the footprint for the cylinder is not directly related to the cylinder quantity as individual inert gas and CO2 cylinders may require a smaller area than a chemical agent cylinder. Other chemical agents may have different space requirements. Inert gases are stored in gaseous form at higher pressures than chemical agents and this allows cylinders to be located further from the protected area than an equivalent chemical agent system. For instance, cylinders for an inert gas system can be located several hundred metres away from the space being protected. This can be an advantage where space for storage is limited. By contrast, the pipework friction losses of a chemical liquefied agent during discharge means that the cylinders have to be sited close to the protected area. The lower storage pressures used in chemical-agent systems (see section 2.3) also means that the grade of pipework and fittings required is not as great as for an inert gas system. Although cylinder storage pressures of around 200 bar are commonly used, the distribution piping is usually designed to be around 60 bar, the same as CO2. Some inert gas systems are stored at pressures as high as 300 bar, but have the same distribution pressure of 60 bar. The pipework used on inert gas systems consists of a high-pressure section and a low-pressure section. The high-pressure section requires pipework and fittings suitable for 100 – 300 bar system operating pressures. The pressure is reduced at the end of its high-pressure section to 60 bar by a pressure reducer. After this point the pipework and fittings need only be selected for a 60 bar system operating pressure. This lower operating pressure generally constitutes the majority of the pipework in an inert gas system.



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Cylinders for use on all systems should be stored away from severe weather conditions, out of direct sunlight, and be protected from potential damage due to mechanical, chemical or other causes. Generally the operating temperatures for total flooding systems should be in the range of –200C to +500C.

Operation It is important that the system is arranged to operate in a manner suitable for the particular area or business being protected, within the confines of the various applicable standards. The general method of operation involves two major stages which covers the extinguishing system itself as well as other engineering systems serving the protected area.

First stage of alarm On automatic detection of the fire, the system should close down any air conditioning serving the protected area. Where the area is served by a central system, dampers must be installed to provide fire separation between the protected area and the rest of the ductwork system. This separation requirement also applies to any other ductwork distribution system. Any ductwork system passing through, (but not serving) the protected area shall either be fully fire rated along the section within the protected enclosure, or be fitted with fire dampers at the points of entry and exit, of the protected enclosure. In the case of stand-alone room air conditioning units, the units should be shut down. In some cases, the system may be configured to initiate a power-down procedure for computer or other sensitive equipment within the space. Activation of the first stage alarm will allow users time to assess the hazard and take suitable measures to fight the fire manually if appropriate, or to determine if it is a false alarm. This assessment should, of course, only be carried out by suitably trained staff. On arriving at the protected area, assuming that it is unoccupied, the users would first ascertain, as far as possible, that the alarm is genuine and therefore assess the risks that entry may pose. If the situation warrants entry, then it may be appropriate to set the system to manual control before entering the space. This will ensure that the extinguishant cannot be discharged while people are in the space. Some users may prefer their systems to be set to manual, while the area is occupied, so as to prevent the extinguishant from being discharged. If this is the case the users would reset the system to automatic when leaving the room. First stage alarm audible and visual alarms would be operational at this time. An aspirating-type smoke detection system may also be employed, but is not normally linked to the fire extinguishing system.

Second stage of alarm The second stage of alarm will be activated when smoke within a room is spreading and being detected by other devices and where the fire extinguishing control system is set in automatic mode. In this condition activation of a second detector on another zone will activate second stage audible and visual alarms, close down any power supplies to equipment in the room via the PDU and activate the pre-discharge timer. After a



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preset period (no more than 30 seconds) for evacuation, the extinguishant would be released. There would normally be a status signal from the detection system serving the protected area to the main building fire detection system to make the occupiers aware of the fire condition. This may be particularly useful to fire service crews on their arrival at the building.

If the extinguishing system is linked to systems such as a Building Management System (BMS), second stage activation can be arranged to send signals to notify these other systems of the status within the protected area. This in turn can allow the BMS to action any changes necessary and appropriate to other building services plant and systems. However, there will be many cases where the above cannot be adhered to due to the operations within the protected space. For instance, some high technology businesses such as internet hotels or bank computer centres are not prepared to risk having equipment off-line, and often go to great lengths to provide redundancy through duplicate plant and systems. In such instances, equipment within the space may be left running throughout both alarm stages. Similarly, the rise in temperature within the space that would result from the air conditioning systems being shut down would be unacceptable and so the air conditioning is left running. If such air conditioning is non-recirculating, then the system should be shut down and dampers closed on second stage of alarm. However, any system or service passing through the space will still have to be fire separated, although such areas are usually designed to avoid such an arrangement. As mentioned earlier, the designer must give very careful thought to the operation of the space and the risks involved when deciding on an operating strategy for the fire extinguishing system. This may involve detailed discussions with the client and the authority having jurisdiction to arrive at a suitable solution.

2.2 DESIGN This subsection deals with the general principles of designing an

extinguishing system, but only to a level sufficient to make the services designer aware of the main considerations. It is not intended that the reader of this document will be in a position to carry out detailed system design. A suitably qualified and accredited professional organisation or specialist must carry out the detailed design of a fire extinguishing system.

System design The main design principles and issues associated with gaseous fire extinguishing systems are covered by BS ISO 14520-1:2000, Gaseous fire-extinguishing systems – Physical properties and system design – Part 1: General requirements. All the information contained below is in accordance with that Standard. Parts 2 to 15 deal with particular requirements for each of the main gases available. It is also very important that, when designers consider the fire extinguishing system, they understand the type and use of the space, and the potential hazards which the system must protect against.



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Safety The Standard referred to above details the safety measures that should be observed with total flooding systems, in both normally occupied and unoccupied areas, and the reader is advised to read and understand them in full. However, for occupied areas, these can be summarised as follows: In areas which are protected by total flooding systems and which are capable of being occupied, the following shall be provided: a) Time delay devices

1) for applications where a discharge delay does not significantly increase the threat from fire to life or property, extinguishing systems shall incorporate a pre-discharge alarm with a time delay sufficient to allow personnel evacuation prior to discharge;

2) time delay devices shall be used only for personnel evacuation or to prepare the hazard area for discharge.

b) Automatic/manual switch, and lock-off devices where required in accordance

with BS ISO 14520:20002, Part 1, Clause 5.2. c) For safe use of systems in the UK, reference should be made to the HAG

report3.

Detection, actuation/operation and control systems The detection, actuation/operation and control part of the protection system can be automatic with additional manual control, or manual operation only. The control system typically includes detecting circuits, releasing circuits (automatic and manual), interfacing circuits, alarm circuits and actuating devices, all with associated wiring. The detection device must be suitable for early detection of fire through smoke as appropriate for the hazards present in the area being protected. To this end, it is important that both the designer and specialist understand the use to which the space is being put so that appropriate equipment can be selected. A combination of ionisation chamber and optical-type smoke detectors should be used as ionisation-type detectors are most sensitive to flaming fires, and optical types respond best to some types of smouldering fires. The detectors should be arranged in an even pattern using equal numbers of both types of detector. Guidance is given in BS 62664 on the spacing of detectors required for areas containing electronic equipment, based on the floor area of the protected space, and also the number of air changes and air velocity in air conditioned areas. BS 62664 recommends that particular measures be adopted when dealing with electronic data processing type installations, such as reducing the area of each detector zone to give greater sensitivity, or taking into account the effects of air movement when locating detectors. Additional fire detection can be provided by the use of aspirating-type smoke detectors. These have much greater sensitivity than either optical or ionisation detectors, and so can detect a fire at a much earlier stage. However, this high level of sensitivity brings its own problems as the systems can be susceptible to the effects of outside sources such as the quality of incoming air. If the air intake for the air conditioning or ventilation system is located near to a source of possible contamination, this may be sufficient to set off the aspirating detector. This can be addressed by adjusting the sensitivity of the system detector. These systems are usually employed for their early warning capabilities, but are not linked to the fire extinguishing system itself.



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It is a requirement of BS ISO 14520-1:20002 that the electrical supply to an electrically operated fire detection system is independent of the general supply to the protected area. The Standard also states that an emergency secondary power supply must also be provided in case of failure of the primary supply (this is normally a battery). For manual operation systems, the user control shall be located outside the protected area or, where this is not possible, adjacent to the main exit from the area. Such manual controls should also incorporate a safety device to restrict accidental discharge, or discharge during maintenance or testing. A hold-off device can be used to suppress operation of the system, as recommended by BS 62664. It is normally located at the exit point from the room and requires a constant application of pressure for it to be effective.

Extinguishant concentration The design concentration of extinguishant is related to the classification of fire to be protected against. For fire Classes A and B (as detailed in ISO 39415), BS ISO 14520-1:20002 states that the extinguishant concentration shall be equal to the design concentration plus a safety factor of 30%. Additional allowance may need to be made for other factors not covered by the safety factor. It goes on, however, to say that more suitable tests for use in areas with large quantities of plastics materials, including computer rooms, are currently being developed for inclusion in the next update of the Standard. The methods for calculating the extinguishant concentration are detailed in Annexes B and C of BS ISO 14520-1:20002.

Discharge time In order to extinguish the fire and restrict the formation of decomposition products due to the heat, the extinguishant must discharge as quickly as possible. However, the discharge time is different for varying extinguishants but can be summarised as follows: • Non-liquefied extinguishants (inert gas): The time required to

achieve 95% of the design concentration shall not exceed 60 seconds

• Liquefied extinguishants: The time required to achieve 95% of the design concentration shall not exceed 10 seconds

However, the maximum flow rate, and hence pressure, occurs very soon after the start of the discharge as shown in Figure 2 and Figure 3 on Page 11.

Duration of protection/hold time The appropriate extinguishant concentration needs to be achieved and then maintained for a sufficient period to ensure effective action. The period during which the concentration is maintained is known as the hold time, and is important in areas where a fire has the potential to become deep-seated, or the original cause persists, such as a faulty battery pack of an uninterruptible power supply unit. As a general rule, the hold time should be not less than 10 minutes and should be proven by carrying out a door fan pressure test using the method described in BS ISO 14520-1:20002.



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With the exeption of nitrogen, extinguishants are heavier than air and, when discharged, produce a heavier-than-air mixture with the room air. As this mix leaks out, the interface formed between the mixture and the infiltrating air taking its place, descends. This is known as a descending interface. The system should be designed such that the extinguishing concentration is still achieved at the top of the highest piece of equipment forming part of the hazard at the end of the hold time.

The enclosure In order to achieve acceptable extinguishant retention times as demonstrated by either a door-fan pressure test or full discharge test in a fire condition, it is essential that the enclosure is of tight construction. Details of the measures that need to be addressed are included in Section 4.11.

Pressure relief With fire extinguishing agents there is a significant increase in pressure in the protected area on discharge that must be assessed and accommodated within the design if necessary. Annex E to BS ISO 14520-1:20002 explains the requirements of such devices in detail, and these are also discussed in Section 4.4 of this document. Pressure characteristics during discharge are shown in Figure 2 and Figure 3.

Figure 2: Discharge graph for non-liquefied extinguishants.

Figure 3: Discharge graph for liquefied extinguishants.

Approximately 5 seconds

Maximum time (95% of minimum design concentration) 60 seconds

Pressure

Approximately 5 seconds

Maximum time (95% minimum design concentration) 10 seconds

Positive pressure

Negative pressure

0



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Inert gas systems generally require careful attention. If insufficient pressure relief is available, discharging a large volume of extinguishant into an enclosure will create an over-pressurisation. For example, for a room of dimensions 10 m long, 5 m wide and 3 m high, the volume is 150 m3. The volume flow rate that must be accommodated through pressure relief devices (if it cannot be absorbed by the enclosure itself) is approximately 2 5 m3/s (from a proprietary calculation program). More instruction is given in Table 4. However, while the volume of gas involved for a halocarbon agent is less (and varies with the type of agent), chemical agents produce a negative pressure due to cooling followed by a positive pressure, both conditions happening during the first few seconds of the discharge period.

Integrity testing The protected area should be as air tight as possible to reduce the rate of extinguishant leakage so as to maintain the design concentration for the hold time as described above. Leakage paths generally occur due to poor construction quality as detailed in Section 4. To achieve a true picture of the performance of a protected enclosure, an integrity test needs to be carried out after all works have been completed. Any leakage found during the test should not be included as part of any engineered pressure relief system. In all instances, the enclosure should be sealed as effectively as is practicable and an engineered pressure relief solution provided. The most widely accepted method for determining the integrity of an enclosure is to perform a door-fan pressure test, and such a test is described in detail in Annex E of BS ISO 14520-1:20002. A fan is temporarily fitted into the doorway of the protected area to create a pressure within the enclosure. A series of pressure and airflow measurements are then taken from which the leakage characteristics of the enclosure are determined. It is worthwhile carrying out a detailed visual inspection of the protected area or enclosure before any test is carried out so that any obvious leakage routes can be closed. Smoke pencils or other similar equipment can be used to help trace the path of air leakage. Leakage at both high and low level in the area will allow extinguishing agent out and air in depending upon the agent used. The door fan pressure test may be carried out by the fire extinguishing specialist, but it should be recognised that the specialist has no control over construction of the enclosure.



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System extract A separate extract system should be provided to remove the extinguishant after discharge. In the event of a fire, it may also need to remove the products of combustion as well as any decomposition products that may be present with halocarbon gases. Although in normal circumstances, as the system is detecting incipient fires, there will be no decomposition products. The system will need to have motorised fire dampers that are closed in normal operation and during extinguishant discharge. Care must be taken when designing a ventilation system for a protected area to ensure effective ventilation throughout the whole of the enclosure. With the exception of nitrogen, the extinguishant/air mixture is heavier than air and will tend to accumulate at low level, and therefore in these cases it may be considered that the extract point(s) should also be from low level. However, in the case of inert gases, the extinguishant/air mixture is only marginally heavier than air, and it may be considered acceptable to have the point(s) of extract at high level. In some cases it may be acceptable to ventilate the protected area after discharge through externally opening doors and windows, but it will be necessary to talk to the authority having jurisdiction through the Building Control Officer or Fire Officer and the insurer if the designer or specialist is planning to install anything other than a dedicated mechanical extract system. The ventilation system may be under the control of the local fire authority who will operate it only when sure that the source of activation of the extinguishing agent has been dealt with successfully. Where possible the extract should pass straight to outside without passing through any other space, discharging directly to atmosphere without any possibility of recirculation. A damper with positive shut-off must be fitted to prevent excessive leakage of extinguishing agent in the event of a discharge. Such a system can, however, be used in some systems to provide pressure relief at the time of discharge, as discussed earlier. If so, a pressure relief damper/flap must be installed.

Verification of the system On completion of an installation, the fire system should be tested in accordance with the requirements detailed in Section 8 of BS ISO 14520-1:20002, and should include the following; • Enclosure check • Review of mechanical components • Review of enclosure integrity • Review of electrical components • Preliminary functional tests • System functional/operational test • Remote monitoring operations (if applicable) • Control panel primary power source.



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On completion of tests the building user must be provided with a completion certificate, instructions, and full design information for the as-installed system, including design concentrations and information on the door-fan pressure testing. The user should also be provided with a statement to the effect that the system complies with the appropriate requirements of the standards, and has been approved and accepted by the authority having jurisdiction. It may also be advisable to carry out further integrity tests after the building has been occupied for a while following completion. Any settlement of the building fabric and structure may result in cracks providing additional leakage paths.

2.3 EXTINGUISHANTS Halon

For many years halon was seen as the most effective agent for use in fixed fire-extinguishing systems. It is very effective at putting out fires at the very early stages of their growth, and as a result reduces property and equipment damage due to fire and smoke. However, more recently, the link between halon and harm to the environment has been demonstrated. As a result, the 1990 Montreal Protocol banned the production of Halon 1301, 1211 and 2402 in developed countries from 31st December 1993. Subsequent European legislation, EC Regulation 2037/20006, went further and prohibited the recharging of existing halon fire-fighting equipment from 31st December 2002. Furthermore, with the exception of equipment deemed as critical under the Regulation, fire-fighting equipment in the EU containing halon must be decommissioned before 31st December 2003. The critical categories referred to in the Regulation where Halon 1301 is permitted are: • In aircraft for the protection of crew compartments, engine nacelles,

cargo bays and dry bays • In military land vehicles and naval vessels for the protection of spaces

occupied by personnel and engine compartments • For the making inert of occupied spaces where flammable liquid

and/or gas release could occur in the military and oil, gas and petrochemical sector, and in existing cargo ships

• For the making inert of existing manned communication and command centres of the armed forces or others, essential for national security

• For the making inert of spaces where there may be a risk of dispersion of radioactive matter

• In the Channel Tunnel and associated installations and rolling stock.



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Inert gas Inert gas systems extinguish fires by reducing the ambient oxygen concentration from 21% to between 12% and 14%, - below the level required to support combustion. Achieving the exact concentration is very important as oxygen levels under 10% are considered too low for human safety, although the protected area should be evacuated prior to discharge. The inert gas agents are electrically non-conductive clean fire suppressants, used in concentrations of between 35-50% by volume and are typically made up of nitrogen and argon in varying quantities, with one agent also containing carbon dioxide. Some of the major inert gas systems widely used are detailed in the table below.

Table 2: Commonly used inert gases.

Designation Gas blend Trade name

IG-01 100% Argon Generic

IG-100 100% Nitrogen Generic

IG-55 50% Nitrogen/50% Argon Argonite

IG-541 50% Nitrogen/42% Argon/8% Carbon Dioxide

Inergen

Figure 4: Gas cylinder installation.

The inert gases are stored in gaseous form under high pressure in cylinders, and are also discharged as a gas. The system is flexible in that the cylinders do not have to be stored close to the area being protected, but can be positioned hundreds of metres away if required. Inert gas systems are environmentally friendly, generally having zero ozone depletion potentials (ODP) and zero global warming potentials (GWP).

Typical applications for inert gas systems are: • Telecommunications facilities • Computer rooms • Control rooms • Transformer and switchgear rooms • Record storage • Flammable liquid hazards • Shipboard machinery spaces



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Halocarbon agents Most chemical agents extinguish fire through a combination of heat absorption and, to a lesser extent, chemical interference with the combustion chain. A number of chemical or halocarbon agents are shown in Table 3.

Table 3: Commonly used halocarbon agents.

Designation Chemical formula Chemical name Trade name

HFC 23 CHF3 Trifluoromethane FE-13

HFC 125 CF3CHF2 Pentafluoroethane FE-25

HFC 227ea CF3CHFCF3 Heptafluoropropane FM-200/FE-227

FK-5-1-12mmy2 CF3CF2C(O)CF(CF3)2

Dodecafluoro-2-methylpentan-2-one

Novec 1230

Halocarbon agents are stored in liquid form at a lower pressure than inert gases, and as such take up less volume than their inert gas counterparts. The cylinders are charged with a nitrogen propellant so that, when the gas is released, the nitrogen pushes the liquid extinguishing agent through the pipe network and out through nozzles. As the chemical is stored at a low pressure, the storage cylinders or vessels may need to be located closer to the protected area than an equivalent inert gas system. This needs to be borne in mind at the design stage as it may affect the type of system chosen. The new halocarbon agents were specifically developed to meet the demands of the Montreal Protocol for halon alternatives, and are not listed in EC Regulation 2037/20006 as being due for phasing out. However, they are often classified as greenhouse gases, with some agents having significant GWP (global warming potential) levels. As the greenhouse gases fall under the Kyoto Protocol, any release, however small, must be counted towards the total national emissions inventory for such chemicals. Having said that, gases in fixed fire suppression systems are regarded as essentially non-emmissive and the continuing use of HFCs is recognised within a UK Voluntary Agreement between the Fire Industry Council (FIC) and the UK Government. FK-5-1-12mmy2 is a fluorinated ketone with negligible GWP and is exempt from any potential control under the Kyoto Protocol. Typical applications for halocarbon agent systems are: • Telecommunications facilities • Computer rooms • Control rooms • Transformer and switchgear rooms • Flammable liquid hazards • Shipboard machinery spaces • Aero engine compartments.



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Carbon dioxide Carbon dioxide protection systems require particular measures to be applied to their use and management as it is both toxic and an asphyxiant at the concentrations necessary to extinguish fire. When the protected area is occupied, the carbon dioxide system must not be on automatic control. The addition of odourisers to the system would assist in detecting a discharge as the gas itself is colourless and odourless. Carbon dioxide is a clean agent with good penetrative qualities, and as such is suitable for use on live electrical equipment, including enclosed equipment. However, as large storage quantities are necessary due to the high storage pressures and concentrations needed to be effective, space and weight become important issues that need to be carefully considered. Typical applications for carbon dioxide systems are: • Telecommunications facilities • Computer rooms • Control rooms • Transformer and switchgear rooms • Record storage • Flammable liquid hazards • Shipboard machinery spaces.

Foam Foam systems – both low and medium expansion – act like a combination of inert gas and halocarbon systems by excluding the oxygen source and reducing the heat of the fire. This makes foam systems suitable for liquid pool fires, but, conversely, they are not effective in dealing with running or spray fires. However, the appropriate foam compound must be used for the particular hazard being dealt with as the chemical reaction with some liquid fuels destroy the blanket formed by the foam. Similarly, as the foams are mainly aqueous solutions, they should not be used to protect against anything that would react violently with water. High expansion foam systems work primarily by smothering the fire, but this gives a risk of poor visibility and suffocation in occupied areas. Typical applications for foam systems are: • Warehouses • Document stores • Libraries • Computer room floor voids • Flammable liquid hazards • Engine compartments • Cable tunnels • Shipboard machinery spaces.

Dry powder These systems are used to protect against flammable liquid and spray fires, although great care must be taken in the selection of the type of powder as different types address different types of fire.



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Powders can provide rapid extinguishing but are largely ineffective once the powder has settled. They are also generally not recommended for use in occupied areas as they are unpleasant to breathe and obscure visibility. Typical applications for dry powder systems are: • Flammable liquid hazards • Vehicle engine compartments • Shipboard machinery spaces.

Fine water spray/water mist NFPA 750:20007 classifies three types of protection for fine water spray systems: fire control, fire suppression or fire extinguishant. If a manufacturer of a bespoke fire suppression system claims the product is a fire extinguishant in order to reduce the period of discharge, conclusive testing information should be produced by the manufacturer to confirm the viability of the proposals. In order to comply with the requirements of the only standard currently in force, NFPA 750:2000, consideration must be given to the period of the discharge, which may be 30 minutes or more. Pneumatic powered systems are unlikely to be capable of lasting an adequate time and providing continuous pressure, in which case pump power is more appropriate. There are two basic categories of fine water spray systems: single fluid systems and dual systems. Single fluid systems can use either water stored at pressures varying from 12·1 bar or less to 34·5 bar or greater, or by the use of a pump. These systems discharge through nozzles that produce droplets from smaller than 400 microns up to 1000 microns. Dual systems incorporate a gas such as air or nitrogen to atomise the water at the point of discharge. Both systems are not particularly good at penetrating directly into shielded areas as would a gas system, so careful thought needs to be given to the selection and location of the discharge components. This means that the design and engineering aspects of such systems are complicated in comparison to many other systems, and each case must be individually considered. As these systems are capable of using de-ionised water it is feasible to use the medium on live electrical equipment. However, as with foam systems, these systems should not be used on fires where there is a likelihood of a violent reaction with water. Typical applications for fine water spray/water mist systems are: • Transformer and switchgear rooms • Flammable liquid hazards • Shipboard accommodation, storage and machinery spaces • Combustion turbine enclosures • Rotating electrical equipment • Cable tunnels and voids.

STANDARDS


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3 STANDARDS

There are a large number of standards which deal with the provision of fire systems. Some standards address the systems as a whole while others concentrate on particular aspects or elements of such systems. The main standards are included below to help the user to find the relevant information quickly. However, there are also a number of supplementary standards that may be applicable in a more peripheral manner, such as fire resistant cables, and these have not been detailed. It has been assumed that the particular engineer or specialist dealing with that aspect is aware of, and conversant with, such standards. BS ISO 14520 Gaseous fire-extinguishing systems – Physical properties and system design: • Part 1: General requirements • Part 2: CF3I extinguishant • Part 3: FC-2-1-8 extinguishant • Part 4: FC-3-1-10 extinguishant • Part 6: HCFC Blend A extinguishant • Part 7: HCFC 124 extinguishant • Part 8: HFC 125 extinguishant • Part 9: HFC 227ea extinguishant • Part 10: HFC 23 extinguishant • Part 11: HFC 236fa extinguishant • Part 12: IG-01 extinguishant • Part 13: IG-100 extinguishant • Part 14: IG-55 extinguishant • Part 15: IG-541 extinguishant Part 1 of BS ISO 14520 is the main document to be used for the design of gaseous fire extinguishing systems, and offers invaluable advice. Although it may provide the rules for the detailed design of systems which would normally be carried out by the fire protection specialist, the information it contains is also of great interest and use to services designers. Parts 2 to 15 of BS ISO 14520 deal with the particular requirements of the gaseous extinguishants being used. They do not cover foam, powder and water. BS 5306 Fire extinguishing installations and equipment on premises contained in the following parts: • Part 0: Guide for the selection of installed systems and other fire

equipment • Part 4: Specification for carbon dioxide systems • Part 5: Halon systems 5.1: Specification for Halon 1301 total flooding systems 5.2: Specification for Halon 1211 total flooding systems • Part 6: Foam systems

6.1: Specification for low expansion foam systems 6.2: Specification for medium and high expansion foam systems

• Part 7: Specification for powder systems

STANDARDS 3

STANDARDS


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BS 5839 Fire detection and alarm systems for buildings: • Part 1: Code of practice for system design, installation and servicing BS 6266 Code of practice for fire protection for electronic equipment installations. BS 7273 Code of practice for the operation of fire protection measures: • Part 1: Electrical actuation of gaseous total flooding extinguishing

systems • Part 2: Mechanical actuation of gaseous total flooding extinguishing

systems. BS EN 54 Fire detection and fire alarm systems: • Part 1: Introduction • Part 2: Control and indicating equipment • Part 3: Fire alarm devices. Sounders • Part 4: Power supply equipment • Part 5: Components of automatic fire detection systems. Heat

sensitive detectors - point detectors containing a static element • Part 7: Smoke detectors. Point detectors using scattered light,

transmitted light or ionisation

• Part 8: Components of automatic fire detection systems. Specification for high temperature heat detectors

• Part 9: Components of automatic fire detection systems. Methods of test of sensitivity to fire

• Part 10: Flame detectors. Point detectors

• Part 11: Manual call points

• Part 12: Smoke detectors. Line detectors using an optical beam. LPR 16 Gaseous fire protection systems. NFPA 750: 2000 Standard on water mist fire protection systems. In addition to complying with the above standards, fire protection systems, and pipework for systems marketed within the European Union must also comply with the requirements of the Pressure Equipment Directive (PED) 97/23/EC8 and be marked accordingly, including the CE mark where appropriate.

DESIGN CONSIDERATIONS


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4 DESIGN CONSIDERATIONS 4.1 GENERAL Although the detailed design of a fire extinguishing system may be

carried out by a specialist company, there are many aspects of a system which the services designer needs to be aware of and take into account when designing the other building services systems. Only by addressing these related issues can a hazard be adequately protected in the case of a fire by the fire extinguishing system acting as designed.

This section deals with extinguishing services other than the extinguishant system itself. Section 2 covers the extinguishant system.

4.2 PROGRAMMING A fire extinguishing system can have implications for other elements of a

protected area, so it is very important that the project programme should be arranged to enable the fire protection specialist to be involved as early as possible. Insufficient time allowed for at this stage will inevitably result in delays later. Time should also be allowed within the project programme for discussions with the local authority to agree design principles of the system, and again later in the design period for more detailed talks to obtain approvals for the final scheme design. This particularly applies to the requirements for over-pressure relief and extinguishant extract systems where the requirements could have structural or aesthetic implications. The programme must also allow a suitable period for the specialists to prepare and have approved their detailed design scheme. This period may be relatively lengthy for complex buildings or protected spaces, particularly where the client or building user has stringent operational or security arrangements.

4.3 PROCUREMENT Contractual arrangements for employing the fire protection specialist

may depend on many factors including the complexity of the project, the nature of the protected areas, project programme, and the form of contract. Thought must be given to the way that the fire protection specialist is to be employed. If the specialist is to be involved during the design phases of the project before a main contractor has been appointed, then a separate contract may need to be entered into between the client and the specialist. On this basis, the specialist could be appointed to carry out just the design work initially, with the opportunity to tender for the installation work at a later date, either as a direct or specialist contract, or as a sub-contractor to the main contractor. Alternatively, the specialist could be employed as a nominated sub-contractor whereby the main contractor is told to employ an individual or firm for that particular element of the work and does not have the choice of employing another company.

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4.4 EXCHANGE OF INFORMATION

As can be seen from Section 2, there are a number of issues that must be raised at an early stage in the project, and the services consultant/designer must be aware of these in order to be able to assist other members of the design team to design their elements. It is very important to ensure that the structure or envelope of the protected enclosure is suitable for the fire protection system to be installed. Any major alterations to the enclosure that may be required once construction has begun can result in delays and additional costs. These penalties could be avoided with the designer being aware of the issues, and making these known to the architect and structural engineer at the appropriate time. Construction measures necessary to accommodate pressure relief arrangements can also be a significant issue. The design team should be discussing the project and the proposed approach to fire protection with the local authority at the earliest possible stage in the design to be able to incorporate any requirements of the Building Control Officer or Fire Officer. Any large openings that may be required through the structure need to be addressed during the design stage to arrive at the most effective solution. Again, the accommodation of large pressure relief shafts once the structure of a building is under construction will inevitably be disruptive and costly. These can also have an effect on planning approvals, as the location of any discharge grilles or louvres could have a significant impact on the building’s visual appearance. Maximum benefit is likely to be gained from the fire protection specialist being involved at the start of the project. However, due to the nature of most contractual agreements in this country, the specialist is often employed under a separate contract or sub-contract only once the project has been designed and issued to tender. Irrespective of the stage the specialist is employed, it is vital that the individual or firm is made aware of the overall design of the project, and is notified of any changes to the protected area and its immediate environs as soon as they are proposed. What may seem like an insignificant alteration to one member of the design team could have serious consequences for the fire protection specialist. A system should be put in place during the design phases to cover the delivery and receipt of information between members of the team. This may include the local authority and specialist contractors or sub-contractors, as well as the client and the architect, structural engineer, services consultant and quantity surveyor. This will help to ensure that all parties are aware of any design changes that may affect the fire protection scheme, and any problems that may arise can be picked up and dealt with as soon as possible.



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4.5 AIR

CONDITIONING SYSTEMS

For the purposes of this document, air conditioning systems serving protected spaces can be divided into two categories: • ducted systems served from central plant and

• free standing air conditioning units

Ducted systems served from central plant This arrangement generally consists of supply and extract ductwork taken from the central air conditioning distribution system to provide cooling, (or, in some instances, fresh air only), to the protected space. In this case, on activation of the fire protection system, the air conditioning ductwork must be sealed off to prevent products of combustion being spread outside the protected enclosure, or for an added component of combustion in the form of oxygen-rich fresh air being supplied into the enclosure and thus hindering the effectiveness of the fire extinguishant. This will also stop extinguishant being lost from the enclosure to the air-conditioning system. This is best achieved by having fire-rated dampers mounted within the risk area perimeter wall. These dampers would be controlled by a signal from the fire protection system, and activation of the fire system automatically closes the dampers, via the BMS, to provide an airtight seal. Typically, each damper would be held open by a solenoid which derives its power from a source provided via the power distribution unit (PDU). On activation of the fire extinguishing system, the power at the PDU shuts down, allowing the dampers to close under the force of a spring. The dampers should be carefully selected to provide adequate airtight sealing against both the positive and negative pressures developed throughout the operating sequence of the extinguishant. Care should be taken, however, when the volume of air going to the protected area represents a substantial proportion of the duty of the system. Closing down the dampers in such a case could seriously disrupt the balance of the system, possibly resulting in severe over-pressurisation of other areas. In areas with variable air volume systems, stopping the flow of air through the protected area should have less of an impact. Any subsequent increase in pressure detected in the system as a whole would result in a reduction of fan duty, either by slowing the fan speed or by varying the pitch of the fan blades.

Free standing air conditioning units Free standing air conditioning units are generally not connected to a central air conditioning system, but rather draw air from within the protected area through the unit and then discharge it back into the space.



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Typically the units fit onto the flooring system and take air from the room through the top of the unit, pass it through the air conditioning unit where its temperature and humidity are modified to the desired conditions, and then returned to the space through the bottom of the unit into the floor void. This arrangement is known as down-flow, whereas discharging air into the room from the top of the unit is known as up-flow. On activation of the fire protection system, the power to the stand-alone air conditioning units should be isolated to avoid the risk of fire spread. This is particularly important if the stand-alone unit were the source of the fire. As mentioned earlier, this is not always possible as the resultant temperature rise in the space due to the air conditioning being shut down may not be acceptable. This needs to be addressed on an individual application basis. It is not a strict requirement of BS ISO 14520-1:20002 that recirculation air conditioning systems (either stand-alone units or central air handling units) serving solely the protected space need to be isolated on activation of the fire protection system. This is because there is no risk of contamination to other areas by the products of combustion, or of losing protection through the extinguishing agent spreading to other areas. However, isolation is still advisable, as the self-contained air conditioning system may be the source of the fire. Also, if extensive ductwork outside the protected area is utilised, this has the effect of increasing the volume of the protected area and hence the volume contained therein should be added to that of the protected area. In some situations, if the stand-alone air conditioning units are left running once a fire has been detected, the air movement created by the units could exacerbate the situation, either by making detection of the exact location of the source of the alarm difficult to determine, or by fanning the flames and aiding in the development of the fire.

Other associated services Other services that support or are associated with the air conditioning system should also be considered. • Routing of water pipes for humidification

• Chilled water/direct expansion (DX) refrigerant pipework

• Condensate drainage Where such services penetrate the walls of a protected area, they should be adequately sealed to prevent loss of pressure in the space on discharge of the extinguishant. Similarly, appropriate measures need to be applied to make sure that the fire integrity of the enclosure is maintained by the use of fire seals and collars.



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4.6 VENTILATION

SYSTEMS General ventilation As discussed in Section 2.1, the first stage initiation of the fire detection system, should involve ventilation systems being turned off and sealed off from other areas with dampers. This includes systems that serve the protected area, such as fresh air systems where the cooling is carried out by free standing air conditioning units and any local extract units. Any ductwork systems that pass through the space but may not have been constructed and tested to withstand the large overpressures experienced during extinguishant discharge, or do not have sufficient fire rating to maintain the integrity of the protected space, should also have dampers installed at the entry and exit points of the room to maintain the integrity of the protected enclosure.

Pressure relief Responsibility for designing a suitable pressure-relief system generally rests with the services designer rather than the fire extinguishing system specialist, as ventilation systems are often outside their area of expertise. Pressure relief measures must be incorporated into the overall design of the protected area and, as mentioned earlier, the venting requirements for a large space can be considerable. Figure 5 shows a pneumatically actuated pressure-relief damper located in the wall of a vent shaft. It is vital to assess and incorporate the necessary requirements at the right stage in the project.

Figure 5: Pressure relief damper with pneumatic actuation.

When designing a pressure relief scheme, the following issues should be considered:



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Strength of the enclosure A rule of thumb of 500 Pa is typically used as the pressure which an enclosure is able to withstand, but a detailed assessment should be carried out by the structural engineer for the construction being used. While a lightweight demountable partition is likely to offer much less strength than a solid enclosure, it does have the ability to absorb the force exerted and deflect to avoid damage.

The relief of pressure It is bad practice to carry out an integrity test and then use the results obtained to reduce the size of the aperture needed for pressure relief. Once the leakage areas have been established, the enclosure should be sealed to the best practical extent and vents fitted as necessary to limit the pressure fluctuations during extinguishant discharge to within the strength capabilities of the enclosure boundaries. Any leakage identified at this time cannot be considered to be permanent as sealing of the area may take place after the fire protection system has been completed and commissioned. This would have the effect of varying the available vent free area. Section 10.3.3 of BS 5306-4:20019 details a methodology for calculating the area of opening required for venting carbon dioxide (CO2) systems, but different methodologies are required for each type of extinguishant. Extinguishant manufactures provide computer calculation software to specialists to enable them to determine the exact pressure relief requirements, and advice should always be sought from the fire systems specialist. However, Table 4 gives rough rules of thumb for areas of pressure relief required for the common extinguishant systems for a variety of room sizes with proven integrity. The data can only be used at the early stages of a project to plan for any required pressure relief measures. The table should not be used for detail design purposes. This information can only be determined once the extinguishing system has been designed in detail as the volume flow rate profile and volume of gas to be vented are vital components for sizing the area of pressure relief.

Table 4: Area of pressure relief required for different system types for typical room volumes.

Room volume cubic metres

System type 50 100 150 200 250 300 350 400 450 500

Inert gas 0·04 m2 0·07 m2 0·10 m2 0·14 m2 0·17 m2 0·20 m2 0·23 m2 0·26 m2 0·29 m2 0·44 m2

Chemical 0·02 m2 0·04 m2 0·06 m2 0·07 m2 0·09 m2 0·11 m2 0·13 m2 0·15 m2 0·17 m2 0·18 m2

CO2 0·03 m2 0·05 m2 0·07 m2 0·10 m2 0·12 m2 0·14 m2 0·17 m2 0·19 m2 0·21 m2 0·25 m2

When selecting pressure relief devices for a chemical agent system where a negative pressure is generated initially on discharge of the extinguishant (due to the initial rapid reduction in temperature), the device must be capable of providing relief in the required direction at the appropriate time if the negative pressure cannot be adequately accommodated within the space itself.



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A very effective way of controlling the opening and shutting of the damper to control the pressure in the space is to use pneumatic control. On discharge of the extinguishant, a pneumatic control line from the extinguishant system operates the damper. A pneumatic timer is used to determine when the damper closes. Pressure relief vents which use weighted flaps are also effective as these are opened by the increasing pressure within the protected area and closed by gravity as the pressure decreases.

Location of the relief Consideration must be given to the location of any pressure relief apertures or devices. Incorrectly sited apertures could allow far too much of the suppressant to be exhausted at discharge. For example, this could occur if the apertures were placed too close to discharge nozzles.

Pressure relief into adjacent areas When designing pressure relief to an area, the location of the exhaust must be considered. Relieving the pressure into an adjacent area not only extends the area of overpressure, but in the event of a fire also raises the likelihood of an uncontrolled transfer of combustion gasses and smoke into the adjacent area.

Fire rating of dampers BS 62664 states that consideration must be given to the fire separation of any electronic data processing (EDP) area. It is therefore imperative that any penetration through the enclosure walls be adequately fire-rated. Devices such as non-return type flaps, which operate purely on over-pressurisation of the protected area, are only suitable when used to open directly to an external location or when interconnecting ductwork is fire rated.

Positive and negative pressure As mentioned earlier, some agents create both a negative and positive pressure during the course of discharge into the protected area. As above, this means that simple non-return pressure relief flaps are not always suitable as they only act in a single direction.

Back pressure of devices and ducting When a discharge takes place the resultant displaced volume of air is forced out through the pressure relief device. However, the very large volumes of air to be displaced in such a short time impose some unusual conditions on the relief components.

From the pressure rating of the room, the free area required for pressure relief and the full size of the relief vent area can be determined by calculation and then, in turn, the full size of the relief device. It is vital that the actual free area of the device is considered as some flap-type dampers offer as little as 40% free area.



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The pressure relief device will impose a backpressure caused by the resistance to airflow of a large volume of air. In addition to the damper, there are likely to be exhaust grilles, external louvres and possibly even interconnecting ductwork, all of which impose additional resistance to the flow of air from the protected space.

The basic pressure relief vent is sized assuming that the exhaust is directly to atmosphere, i.e. the vent is fitted to an external wall. Any grilles or louvres on the outside of the pressure relief vent to prevent the ingress of weather and wildlife and to maintain the security of the building must not reduce the free vent area specified for pressure relief venting. However, if the pressure relief exhaust has to be ducted away to another location (for example for a room with no external walls), friction losses and changes of direction induce a pressure drop in the duct, which reduces the efficiency of the pressure relief and may cause over pressurisation of the protected area if no allowance is made for it. The pressure drop at the exhaust end of the pressure relief ducting must be considered to ensure that this is the case.

The effect of this is that the additional pressure generated is transferred to the pressure exerted on the room. For example, although the room may be rated at 500 Pa and the designer used that figure for calculating pressure relief, the additional back pressure may impose a further 200-300 Pa to the room pressure. This new figure of up to 800 Pa may not have been considered when designing the structure.

Non-return flaps will create the greatest resistance to air flow, whereas opposed blade dampers in the fully open position cause the least, and can also be fire rated.

To illustrate the possible implications of back pressure, the example shown in Section 2.2 for an inert gas system gives the following figures:

• Room volume: 150 m3 • Air flow: 2·5 m3/s • Area of vent opening: 0·13 m2 (from Table 4) • Velocity through opening: 2·5 m3/s = 19·2 m/s 0·13 m2

From reference to Figure 4.2, CIBSE Guide C,200110, this velocity will impose a pressure drop, or back pressure, in excess of 8 Pa/m in any ductwork forming part of the pressure relief system. Also, an external louvre would add in excess of a further 150 Pa. In reality, from data supplied by damper manufacturers, the maximum velocity recommended through a suitable damper is 15 m/s. This would require a damper of 0·5 m x 0·5 m, assuming a free area of 80%, which would itself impose a pressure drop of around 75 Pa. Using this reduced velocity in ductwork of a similar cross sectional area to the damper gives a pressure drop through that of only 4 Pa/m.

Pressure relief through adjacent spaces In cases where the protected space involves a series of sub-divided compartments, separate pressure relief should be considered for each compartment.



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Active exhaust The pressure relief from an area should not rely on the on the operation of an extract fan elsewhere in the building.

Power supplies The power source to any pressure relief device must be protected against mains failure.

Commissioning and maintenance Following the installation of the pressure relief system, the commissioning company should confirm at the time of commissioning that the system operates correctly, in the correct sequence of events agreed and for the prescribed time periods. During maintenance it is important that not only the normal system tests and checks are carried out, but also the operation of the pressure relief system. Moving of partitioning or positioning of furniture should also be carefully assessed to make sure that no aspect of the system is affected.

Cylinder storage areas Consideration must be given to the venting of storage enclosures, and outward opening doors.

Extinguishant extract A separate extract system should be provided for evacuation of the gases once they have discharged. The system should ideally extract straight to outside without passing through any other areas. However, where this cannot be avoided, the ductwork system must be designed and installed so as to maintain the integrity of both the protected space and other areas it may pass through. These systems should not be part of any other system but must be completely separate.

Fire/smoke extract The local authority may require separate extract systems for fire or smoke, (designed and rated accordingly for the possible temperatures that may be experienced), that can be put under the control of the fire brigade via a fireman’s switch. It is essential to discuss any proposed ventilation systems with the Building Control and/or Fire Officer to ensure approval under any requirements of local codes and standards. This becomes even more important when dealing with buildings covered by Section 20 of the London Building Act which need to comply with their own particular conditions.

4.7 POWER SUPPLIES A power distribution unit, or PDU, comprises several electrical

connections used as a common point to serve the electrical equipment and services within a protected area. The number of PDUs in a protected area will depend on its size and use. All services in the space that require an electrical supply should take that power from a source that can be easily isolated on activation of the fire protection system. Lighting and small power, as well as mechanical plant such as floor standing air conditioning units or general ventilation fans, may be connected to PDUs that serve only that area, and not to switchboards that feed other areas as well.



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A main incoming electrical supply for the protected area should normally come into the PDU, and then equipment will be served via distribution boards or contactors, from the outgoing side of the PDU. Second stage activation of the fire detection element of the protection system should cut off supplies to all the PDUs, and hence to the equipment in the protected space. Staged shutdown of the IT equipment may also be arranged. However, this strategy may need to be changed to suit the operating conditions of the space. For instance, if the air conditioning plant is left on throughout the fire condition, then power for that plant should either be taken from a separate PDU which retains a power supply, or from a source outside the protected space altogether. Also, uninterruptible power supply (UPS) units may need to be kept running in the event of a fire and so may need to derive power from an alternative source, perhaps locating the UPS itself in an adjacent area and taking its uninterrupted power supply cables into the protected space. Where the means of detection is via an electrically operated system, it is a requirement of ISO 14520-1:20002 that the electrical supply is independent of the general supply to the protected area. It goes on to say that an emergency secondary power supply, normally a battery, must also be provided in case of failure of the primary supply.

4.8 CONTROLS The fire extinguishing system should not have control of, or be

controlled by the BMS (or service control system). On activation of the detection circuit of the extinguishing system, a signal should be sent to the BMS. The BMS should then carry out any plant shutdowns or operations necessary for effective operation of the fire extinguishing system such as closing dampers or shutting down air-conditioning or ventilation units. The services designer should liase closely with the controls designer to ensure that the BMS is able to operate plant in the correct sequence on receipt of a signal from the fire extinguishing system, and also to put plant back into the correct operating mode once the fire condition is cleared.

4.9 OTHER FIRE

DETECTION AND ALARM SYSTEMS

Although the fire detection element of the fire extinguishing system to the protected area should cover only the protected area itself, it should be linked to a wider building system for the purposes of fault reporting.

This may be advantageous in monitoring areas that are not normally occupied and can also assist when directing fire-fighting personnel, should that be necessary. Also, other systems such as aspirating smoke detection systems may be installed within the protected space as well as the fire extinguishing system detection circuits. These early warning systems may be employed very close to specific items of plant or computer equipment, due to their high level of sensitivity. They can then be linked to the main building system if required. They should not be integral to the fire extinguishing system.



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4.10 ACCESS CONTROL/ SECURITY SYSTEMS

On activation of an alarm in a protected area any door entry or other security door control devices should be disabled, to permit free movement to and from the space. Unhindered access/egress must be available for evacuation, and subsequent entry for investigation or fire fighting by suitably trained personnel. Where this philosophy is inconsistent with the nature of the business, management procedures should be set in place to maintain security integrity in the event of a fire alarm in the protected space. From a design and installation viewpoint, this may include the need for remote monitoring equipment such as cctv cameras, as the area should have been evacuated on activation of the fire alarm.

4.11 BUILDERS WORK

REQUIREMENTS The enclosure As discussed previously, in order to achieve the air tightness levels necessary to contain the extinguishing agent the enclosure envelope must be designed to provide an effective barrier to both air infiltration and exfiltration. It is therefore necessary to ensure that the following issues are raised with other members of the design team at the earliest possible stage in the project; • cracks, gaps, holes and porosity in the walls, floor and ceiling

envelope elements are effectively sealed.

• envelope components which are specifically designed to open or close such as doors, windows, dampers, etc., provide tight shut-off when in their closed positions.

Some examples of envelope areas where tightness deficiencies frequently occur are; • Walls should be continuous from floor slab to ceiling slab. Where

composite walls are used, the inner ‘air barrier’ component of the wall assembly, i.e. the dry lining, should be continuous from slab to slab.

• The perimeters of the wall/floor and wall/ceiling junctions around the room should be sealed.

• Dry wall linings should have joints sealed including areas above false ceilings and below raised floors.

• Panelled walls should have joints sealed.

• Fixed glazing panels should have their perimeters effectively sealed.

• False ceilings should be of the concealed grid or plasterboard type if the void above is not protected. Lay-in tiles clipped down are not permanent and are insufficient (although such arrangements may be acceptable for general fire protection purposes).

• Junctions in profiled metal sheeting should be sealed.

• Junctions between similar or dissimilar wall, ceiling and floor components should be sealed.

• Where there are significant areas of exposed porous block walls, these should be sealed with an air barrier paint or equivalent, for example light skim of plaster



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• Cracks, gaps and holes around and through envelope penetrations should be sealed including:

− ducts, grilles, pipework, cables, steelwork, conduits, trunking, damper housings, trays, etc.

− door and window frame perimeters and under window sills

− junctions at top of walls with perimeter metal or concrete beams

− vertical columns in walls

− service duct covers

− gaps around floor/ceiling tiles where these penetrate wall linings

− expansion joints

− electrical sockets/fittings

− light fittings.

• Opening doors and windows should be draught stripped with materials providing effective sealing around their perimeters.

• Air handling ductwork serving the enclosure should be fitted with automatically actuated tight shut-off dampers (as discussed elsewhere). Where possible, dampers should be located as close as possible to the boundary of the envelope.

• Drains should be effectively trapped, to deal with the 500Pa room pressure.

• Where a room space is protected but not a ceiling void, luminaires should be of the sealed type.

Even with a tightly constructed envelope, some rooms with a large number of doors, windows and dampers may have difficulty passing an integrity test. It is important that these components provide an effective seal, but it should be noted that some designs or configurations are inherently more leaky and difficult, (if not impossible,) to be made tight. Some examples are as follows and these should be avoided if possible: • Double doors (often metal with glazing panels) without recessed

frame-butting areas in the jambs and across the heads.

• Sliding, roll-over shutter and revolving doors.

• Sash and horizontal sliding windows.

• Drop-type fire dampers and flap-type gravity dampers.

• Equipment heights in excess of 80% of the protected height (the height to which the design concentration of extinguishant is maintained for the hold time).

These are not all of the potential areas which need to be addressed in the construction of the enclosure but they do represent the more common reasons why it may be difficult for a protected area to pass a room integrity test. It is very important to have detailed discussions with the architect at a very early stage in the project to make sure that their building specification is suitably stringent. For example, for both protected spaces and cylinder stores, doors should open outwards.

INSTALLATION CONSIDERATIONS


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5 INSTALLATION CONSIDERATIONS

5.1 GENERAL The best designed fire protection system needs to be installed correctly in order for it to function correctly when needed. Moreover, it needs to interact with the other building and services elements to ensure that it not only operates correctly, but achieves the design aim of extinguishing the fire. It is therefore essential that the installation process is as carefully planned and controlled as the design phase, and guidance is given in this section.

5.2 PROGRAMMING Just as time must be allowed in the programme during the design stages

for the fire protection system, the on-site programme must also be arranged to accommodate it. Fan pressure testing must be programmed at such a stage so as to provide meaningful data for the fire protection specialist. The protected area or enclosure must have been completed before such tests can be carried out. Also, some other operations on site may be dependant on installation of the fire protection system, and the programme must be arranged to reflect this. The installation of ceilings, floors and lighting, for instance, needs to be carefully sequenced. If a specialist is involved early in the project the person will be able to develop sufficient detail to determine approximate pressure relief opening sizes and locations necessary for submissions for planning approval, and to also design structural measures that may be needed. Adequate time should also be allowed within the overall programme for testing and commissioning the system. Should the client wish to have a further enclosure integrity test carried out after completion of the total construction works to make sure that the room is sufficiently air tight after all work has been finished, this must also be accommodated within the programme so as to allow sufficient time for any remedial works that may be required.

5.3 EXCHANGE OF

INFORMATION Exchange of information during the construction phase is just as important as during the design stage. A set procedure should be put in place for issuing information, and time allowed for its action. Some issues are; • Architects instruction

• Request for information (RFI)

• Change order

• Document issue (such as drawings for comment)

• Approvals and submissions (such as drawings and materials)

• Progress reporting

• Testing and commissioning programme

• Test results and commissioning sheets

• Snagging documentation.

INSTALLATION CONSIDERATIONS 5



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Communication must be seen as a two way process. Any party can ask for (or in turn be asked for) information at any time to ensure that work is carried out correctly and on time.

5.4 SITE SUPERVISION As mentioned previously, the quality of the installation is all-important.

Site inspection must be an on-going process, with key elements being checked before they are covered up. For example, the sealing around services passing through walls below raised floors and above suspended ceilings should be checked before the floor and ceilings are erected. This seems a simple example but it is a common defect. Time and resources must be made available for the inspection of the work, and this should be reflected in the programme. It is not acceptable for a contractor to claim a delay because staff were not able to carry out an inspection, but were not given adequate notice. Similarly, the inspection staff should give the contractor sufficient notice that they want to inspect an element of the work so as to avoid disruption on site. There should be clear lines of reporting for site inspection works. This should address the nature of the inspection, the stage in the project it is carried out, the faults found or comments made, the nature of any remedial works necessary, and the distribution of the report. Any follow up work identified within the report needs to be programmed and monitored in line with the general project procedures.

5.5 AIR

CONDITIONING SYSTEMS

Issues to be covered during the construction stage are generally those of either installation arrangement or installation quality. First, have the air conditioning systems been installed as intended, or are there any variations? Second, is the quality of the installations of an acceptable standard? Having designed the air conditioning systems to integrate correctly with the fire protection system, it is obviously important that they are installed to that design. This should include simple issues such as routing of the ductwork and installation of dampers in the correct locations, through to checking that the various components function correctly when required. There are inevitably changes on site during the construction of any large project and these must be checked in the context of their integration with the fire protection system. If, for instance, a section of air conditioning ductwork needs to be routed through the protected area, suitable shut-off dampers must be added at the inlet and outlet points of the protected enclosure room, or fire rated ductwork used, in order to maintain the fire integrity. Similarly, if additional cooling were required to the protected area, then the same measures must be taken with that additional element as were employed on the original services developed during the design stage. On completion, air conditioning systems within the protected area should be checked for correct functionality in a fire condition. When the fire detection system detects a fire and initiates first stage, stand-alone air conditioning units should shut down, and dampers on central systems



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at the point of entry and egress should shut if this is the agreed operational protocol. As discussed earlier, due to the nature of the business activity, some building users may employ different operating strategies for the fire protection system and its interaction with the other systems. In any event, the air conditioning systems should be checked for functionality. Any defects found should be recorded and reported for rectification. Upon completion of corrective works, the system may need to be re-tested.

5.6 VENTILATION

SYSTEMS Many of the points raised in item 5.5 will also apply to this clause. The correct operation of dampers must be checked, as well as any associated fans or equipment that are dealing with the protected area. Operation of the pressure relief system must be thoroughly checked for both compliance with the design and installation quality. It should also be tested for functionality in accordance with the operating strategies. A nitrogen cylinder can be connected to the manifold to create a pressure in the extinguishant distribution pipework, simulating discharge of the extinguishant. Because of the pressure that can be experienced during discharge of the extinguishant, the ductwork must be constructed and supported in a way that is robust enough to withstand such forces. Any defects found should be recorded and reported for rectification. Upon completion of the corrective works, the system may need to be re-tested.

5.7 POWER SUPPLIES The power installation should be checked to make sure it complies with the design. This includes inspecting the alternative supply if provided, as well as carrying out a full functionality check. Any defects found should be recorded and reported for rectification. Upon completion of the corrective works, the system may need to be re-tested.

5.8 CONTROLS The controls installation should be checked to make sure it complies with the design, as well as carrying out a full functionality check. These checks should include the correct operation of interfaces with all other systems such as: • Fire detection and alarm systems

• BMS


• Operation of the fireman’s switch functions Any defects found should be recorded and reported for rectification. The system may need to be re-tested upon completion of the corrective works.



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5.9 OTHER FIRE DETECTION AND ALARM SYSTEMS

Functional tests should be carried out to make sure that the other fire detection and alarm system operates correctly in conjunction with the system covering the protected area where these are linked. Where the fire detection and alarm system serving the rest of the building is completely independent of that serving the protected area, then no particular measures in relation to the protected area are needed. Any defects found should be recorded and reported for rectification. Upon completion of the corrective works, the system may need to be re-tested.

5.10 ACCESS

CONTROL/ SECURITY SYSTEMS

As with other systems, functional tests should be carried out to make sure that the system operates correctly in conjunction with the fire protection system.

Any defects found should be recorded and reported for rectification. Upon completion of the corrective works, the system may need to be re-tested.

5.11 BUILDERS WORK

REQUIREMENTS A full schedule of builders work requirements should be provided before any work starts on site. This should detail the building work that is needed to install the fire protection system, and typically includes the following:

Hole schedule This should contain marked up plans and elevations of the building with holes that need to be formed by the builder or main contractor. These should be a development of the issues discussed with the Architect and Structural Engineer and scheme design information provided during the design phase. As some of these requirements can be onerous and have major implications on the structural design and construction of the building, it is essential to provide as much detailed information at the design stage as possible. This information may be produced by the services design engineer, but would more commonly be supplied by the fire protection specialists.

Trench details In cases where some of the systems run within a slab or beam, a cast in trench may be required. Details should include the width, depth and length of the trench, and should be of sufficient size to accommodate the turning radii of the services, and as with the hole schedule above, as much information should be provided at architectural and structural design stage as possible, leaving only minor changes once the specialist carries out its final detailed design.

Chase details This is similar to the trench details above, but applies to vertical surfaces.



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Making good The work required after the installation of the engineering services should be described, together with any special requirements. This may include detailing any materials that cannot, for example be used due to reactions with the extinguishing agent. Also, the person or company carrying out the making good should be made aware of the operating conditions of the space so that they are able to select the appropriate materials and working method. A typical example of this is that any material used for sealing around ductwork or fire dampers must be able to withstand the pressures involved.

Fire stopping Where services pass through the walls of the protected enclosure, they must be suitably made good to maintain fire integrity of the space. Cable trunking needs to be sealed internally before the lid is put on. The fire stopping measures that are applied should be suitable for use at the high pressures developed when the extinguishant is first discharged. The use of intumescent fire pillows or cushions would not be suitable as they only expand and seal the penetration once they get hot enough, whereas the extinguishing system is designed to extinguish a fire before it becomes established and hence the temperature in the space is still relatively low. Suitable methods may include seal bags and cable transit boxes.

Painting Where painting of the fire protection system is to be carried out by personnel other than the fire protection specialist, it is important that a schedule is produced detailing very specifically the exact pipework to be painted, and in what colour. The colour should be specified in accordance with the appropriate British Standard. A snagging inspection should be carried out and a list of faults prepared if applicable for the builders work elements of the fire protection system as well as the mechanical and electrical components. Poor making good could result in excessive leakage of extinguishant.

5.12 OPERATION AND

MAINTENANCE INFORMATION

On completion of the installation, the specialist must supply a detailed operation and maintenance manual for the fire protection system. The services contractor or sub-contractor may need to provide additional information on the pressure relief system if this element was not covered by the fire protection specialist. As a minimum, the following information should be included; • A full description of the system including the design and operational

methodology

• Details of the design criteria and the volume of installed extinguishant

• A full set of as installed drawings



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• Completed testing and commissioning certificates for the system including room integrity test results

• Manufacturers literature on the equipment installed

• A full maintenance schedule for the equipment making up the system. This should include system verification checks as detailed in Annex F of BS ISO 14520-1:20002. Information on maintenance and inspection is included in Section 9.3 of BS ISO 14520-1:20002.

The above requirements relate specifically to the fire protection installation and are in addition to the general engineering services operation and management manual.

REFERENCES


REFERENCES 1 BS 7273:2000. Code of practice for the operation of fire protection measures. British Standards

Institution. 2000.

2 BS ISO 14520:2000, Gaseous fire extinguishing systems – Physical properties and system design. British Standards Institution. 2000.

3 Report by the Halon Alternatives Group (HAG). A review of the toxic and asphyxiating hazards of clean agent replacements for Halon 1301. May 2001.

4 BS 6266:1992. Code of practice for fire protection for electronic equipment installations. British Standards Institution.

5 ISO 3941:1977. Classification of fires. British Standards Institution. 1977.

6 European Communities (EC) Regulation 2037/2000: Ozone depleting substances (ODS). Applicable from 1st October 2000.

7 NFPA 750:2000. Standard on water mist fire protection systems.

8 Pressure Equipment Directive, 97/23/EC. This is implemented in the UK through Statutory Instruments 1999, No. 2001: The Pressure Equipment Regulations 1999.

9 BS 5306-4:2001. Fire extinguishing installations and equipment on premises – specification for carbon dioxide systems. British Standards Institution.

10 CIBSE Guide C2001. Reference data. CIBSE.

11 Pressure Systems Safety Regulations 2000. Statutory Instruments 2000, No. 128.

REFERENCES

APPENDIX – INSPECTION CHECKLISTS


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APPENDIX A - INSPECTION CHECKLISTS

The inspection checklists have been arranged to cover the complete design and installation process, and to ensure that concerned parties are aware of what is required of them to provide a satisfactory end product. Checklists provided here are: • Project information sheet

• Designer’s checklist (for use by the consulting engineer)

• Fire protection specialist/installers checklist

• Main contractor’s checklist

• Inspection checklists - pre-commencement, interim and final inspection

The project information sheet contains the basic contact details information of the team involved on the project and distributed to all parties. This is to be viewed as a live document and must be updated to reflect any changes in the companies or personnel involved, and reissued. The designer’s checklist refers to the scheme design and will generally be completed by the consulting engineer carrying out that task. Where this role has been carried by a design and build contractor, then this checklist will apply to them. The list will act as an aide memoire to ensure that the installation can begin on site. A copy of this list should be kept on site for completion/amendment throughout the life of the project. It should also be available for inspection by other interested parties as required. The fire protection specialist/installers checklist assumes that the detailed design of the fire extinguishing system is carried out by the specialist, (often also responsible for the installation,) the form should be completed by the specialist. The main contractor’s checklist is to be prepared by the main contractor and is aimed at the successful programming of the integration of the fire extinguishing system installation with the other services systems. The inspection checklists – pre-commencement, interim and final inspection checklists – should be completed by the inspection staff, and used to plot the progress of the installation from before the start on site through to completion. Copies of all checklists should be kept on site for completion/amendment throughout the life of the project, and should be available for inspection by other interested parties.

APPENDIX A – INSPECTION CHECKLISTS

APPENDIX – PROJECT INFORMATION SHEET


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Site/project reference: Date prepared: / /

Site address: Prepared by: Signature: Date revised: Revision No.

Site contact name: Revised by:

Telephone no. Signature: PROJECT INFORMATION SHEET

This sheet should be completed by the *client/architect/project manager at the start of the project, and updated thereafter as necessary. (*delete as necessary)

Client Project manager Contact person: Contact person: Company: Company: Address: Address: Telephone no: Telephone no: Fax no: Fax no: e-mail address: e-mail address:

Architect Quantity surveyor Contact person: Contact person: Company: Company: Address: Address: Telephone no: Telephone no: Fax no: Fax no: e-mail address: e-mail address:

Structural engineer Mechanical services consulting engineer Contact person: Contact person: Company: Company: Address: Address: Telephone no: Telephone no: Fax no: Fax no: e-mail address: e-mail address:

APPENDIX – PROJECT INFORMATION SHEET


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Electrical services consulting engineer Planning supervisor Contact person: Contact person: Company: Company: Address: Address: Telephone no: Telephone no: Fax no: Fax no: e-mail address: e-mail address:

Main contractor Fire protection specialist/contractor Contact person: Contact person: Company: Company: Address: Address: Telephone no: Telephone no: Fax no: Fax no: e-mail address: e-mail address:

Local authority Water authority/supply company Contact person: Contact person: Local authority name: Company: Address: Address: Telephone no: Telephone no: Fax no: Fax no: e-mail address: e-mail address:

Gas authority/supply company Electrical supply authority/supply company Contact person: Contact person: Company: Company: Address: Address: Telephone no: Telephone no: Fax no: Fax no: e-mail address: e-mail address:

APPENDIX – DESIGNER’S CHECKLIST


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Site reference: Date of inspection: / /

Site address: Name of inspector: Signature: Site contact name:

Telephone no. DESIGNER’S CHECKLIST

This checklist should be completed by the person responsible for the scheme design (for example the consulting engineer or architect) prior to commencement of the fire protection installation. Any answers that require more than a yes or no or the space in the adjacent box is insufficient shall be detailed in the comments section on the reverse of this form.

1 Fire protection specialist/contractor information Contact person: Company: Address: Tel: Fax: E-mail:

2 Design information 2.1 Has the detailed design been produced by the fire protection specialist? Yes No 2.2 Does the detailed design meet the specification? Yes No − Adequate space allowance for cylinders? Yes No − Pressure relief venting scheme designed? Yes No − All interfaces with other building services detailed and agreed? Yes No − All structural holes advised and agreed? Yes No 2.3 Are there any variations to the specification? Yes No 2.4 Have the calculations been provided? Yes No 2.5 Have the correct design criteria values been used for the design? Yes No 2.6 Have the correct drawing backgrounds been used for the design? Yes No 2.7 Have the calculations been approved? Yes No 2.8 Have the drawings been provided? Yes No 2.9 Are drawing backgrounds used for design still current? Yes No 2.10 Have the drawings been approved? Yes No 2.11 Does the system need to comply with the Pressure Equipment Directive8? Yes No 2.12 Does the system need to comply with the Pressure Systems Safety Regs11? Yes No 3 Approvals 3.1 Is the fire protection specialist authorised to proceed? Yes No 3.2 Has the fire protection specialist been notified of the approval to start? Yes No 3.2 Has the main contractor been notified of the approval to start? Yes No

APPENDIX – FIRE PROTECTION SPECIALIST/INSTALLER’S CHECKLIST


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Telephone no. FIRE PROTECTION SPECIALIST/INSTALLER’S CHECKLIST

This checklist should be completed by the fire protection specialist/installer prior to commencement of the fire protection installation. Any answers that require more than a yes or no or the space in the adjacent box is insufficient shall be detailed in the comments section on the reverse of this form. 1 Fire protection specialist/installer information Contact person: Company: Address: Tel: Fax: E-mail:

2 Design information 2.1 Has the specification been produced by the designer? Yes No 2.2 Has all the necessary design information been provided? Yes No 2.3 Has the detailed design been completed? Yes No − Adequate space allowed for cylinders? Yes No − Pressure relief venting system designed? Yes No − All interfaces with other services detailed and agreed? Yes No − All structural holes advised and agreed? Yes No 2.4 Has the authority having jurisdiction approved the design? Yes No 2.5 Does the detailed design meet the specification? Yes No 2.6 Are there any variations to the specification? Yes No 2.7 Have the calculations been submitted for approval? Yes No 2.8 Have the calculations been approved by all parties? Yes No 2.9 Have the drawings been submitted for approval? Yes No 2.10 Have the drawings been approved by all parties? Yes No 2.11 Does the system comply with the Pressure Equipment Directive8? Yes No 2.12 Does the system comply with the Pressure Systems Safety Regs11? Yes No

3 Approvals

3.1 Has the builder’s work list been given to the main contractor? Yes No 3.2 Have the builder’s work items been completed? Yes No 3.3 Has the main contractor notified you of the approval to start? Yes No 3.4 Has the work area been cleared? Yes No 3.5 Has a start on site date been agreed? Yes No

APPENDIX – MAIN CONTRACTOR’S CHECKLIST


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Telephone no.

MAIN CONTRACTOR’S CHECKLIST

This inspection procedure should be carried out by the main contractor. Any answers that require more than a yes or no shall be detailed in the comments section on the reverse of this form.

1 Design

1.1 Has the Designer’s Checklist been provided? Yes No 1.2 Has the Designer’s Checklist been completed? Yes No 1.3 Is there any outstanding information required? Yes No 1.4 Has commencement of the installation been approved?

1.5 Has the fire protection specialist provided a builder’s work schedule? Yes No 1.6 Have the necessary approvals been obtained from the local authority? Yes No

2 Preparation

2.1 Have the work areas been cleared? Yes No 2.2 Are any other operatives working in the same area? Yes No 2.3 Has all associated builder’s work been completed? Yes No 2.4 Have all necessary services been installed and commissioned? Yes No 2.6 Is the room/enclosure ready for installation of the fire extinguishing system? Yes No

3 Fire extinguishing system

3.1 Has the fire protection system been installed? Yes No 3.2 Has the system been tested for correct operation and commissioned? Yes No 3.3 Has the pipework been pressure tested? Yes No 3.4 Is any remedial work required to the system? Yes No 3.5 Does the system comply with the Pressure Equipment Directive8? Yes No 3.6 Does the system comply with the Pressure Systems Safety Regs11? Yes No

4 Pressure relief system/ventilation

4.1 Have the fire damper installations been completed and tested? Yes No 4.2 Has the pressure relief system been completed and tested? Yes No 4.3 Has the extinguishant extract system been completed and tested? Yes No

5 Inspection

5.1 Have all inspections been carried out? Yes No 5.2 Is any remedial work required following the inspections? Yes No 5.3 Has the fan pressure test been carried out? Yes No

APPENDIX – INSPECTION CHECKLIST NO. 1


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Telephone no.

INSPECTION CHECKLIST No. 1 – PRE-COMMENCEMENT INSPECTION

This inspection procedure should be carried out by the inspector prior to the commencement of the fire protection system installation. Any answers that require more than a yes or no or the space in the adjacent box is insufficient shall be detailed in the comments section on the reverse of this form.

1 Project information

1.1 Has the project information sheet been provided? Yes No 1.2 Has the project information sheet been completed? Yes No 1.3 Is there any outstanding information required? Yes No

2 Design

2.1 Has the designer’s checklist been provided? Yes No 2.2 Has the designer’s checklist been completed? Yes No 2.3 Is there any outstanding information required? Yes No 2.4 Has commencement of the installation been approved? Yes No 2.5 Has the fire protection specialist provided a builders’ work schedule? Yes No

3 Main Contractor

3.1 Has the main contractor’s checklist been provided? Yes No 3.2 Have parts 1 and 2 of the checklist been completed? Yes No 3.3 Is there any outstanding information in parts 1 and 2 required? Yes No 3.4 Has commencement of the installation been approved? Yes No

4 Preparation

4.1 Have the work areas been cleared? Yes No 4.2 Are any other operatives working in the same area? Yes No 4.3 Has all associated builder’s work been completed? Yes No 4.4 Have the necessary approvals been obtained from the local authority? Yes No 4.5 Have all other necessary services interfaces been completed? Yes No



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Telephone no.

INSPECTION CHECKLIST No 2 – PRE-COMMISSIONING INSPECTION

This inspection procedure should be carried out by the inspector immediately prior to commissioning of the fire protection system installation. Any answers that require more than a yes or no shall be detailed in the comments section of this form.

1 General

1.1 Has the Pre-commencement Inspection Checklist been provided? Yes No 1.2 Has the Pre-commencement Inspection Checklist been completed? Yes No 1.3 Is there any outstanding information required? Yes No

2 Extinguishing system - electrical installation

2.1 Has the system pipework been bonded? Yes No 2.2 Have the first stage alarm and fault circuits been tested? Yes No 2.3 Have the second stage alarm and fault circuits been tested? Yes No 2.4 Have the extinguishant Hold-off and fault circuits been tested? Yes No 2.5 Has the panel been isolated from the mains and batteries? Yes No

3 Extinguishing system - mechanical installation

3.1 Are pipework and nozzles located in accordance with the drawings? Yes No 3.2 Are pipework and nozzles properly supported and fixed? Yes No 3.3 Are pipes sizes as shown on the drawings? Yes No 3.4 Are all nuts, bolts and fittings properly installed and tightened? Yes No 3.5 Has pipework been checked for continuity and freedom from blockages? Yes No 3.6 Has pipework system been swabbed out and pressure tested? Yes No 3.7 Are all nozzles (where applicable) above head height and correctly

orientated? Yes No

3.8 Are all extinguishant cylinders properly located and securely fixed? Yes No 3.9 Have the extinguishant quantities been checked? Yes No

4 Pressure relief system

4.1 Have the pressure relief dampers been operated? Yes No 4.2 Have the dampers been made good around the frames for fire integrity? Yes No 4.3 Has the damper control actuation system been tested? Yes No 4.4 Have the discharge louvres been fitted? Yes No



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5 Extinguishant extract system

5.1 Has the extract fan been operated? Yes No 5.2 Has the fan been made good around the chassis for fire integrity? Yes No 5.3 Has the fan control actuation system been tested? Yes No 5.4 Have the discharge louvres been fitted? Yes No

6 Other services installations

6.1 Have the interfaces with the air conditioning systems been completed? Yes No 6.2 Have the interfaces with the ventilation systems been completed? Yes No 6.3 Have the interfaces with the power systems been completed? Yes No 6.4 Have the interfaces with the controls systems been completed? Yes No 6.5 Have the interfaces with the fire alarm systems been completed? Yes No 6.6 Have the interfaces with the access/security systems been completed? Yes No



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Comments:



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Site address: Name of inspector: Signature:

Site contact name:

Telephone no.

INSPECTION CHECKLIST No 3 – FINAL INSPECTION

This inspection procedure should be carried out by the inspector once they have been notified that the installation of the fire protection system is complete. Any answers that require more than a yes or no shall be detailed in the comments section of this form.

1 Detection system 1.1 Has the equipment been located correctly? Yes No 1.2 Is the wiring installation satisfactory? Yes No 1.3 Is the control panel accessible, clean and undamaged? Yes No 1.4 Is the power supply live and has the mains failure fault circuit been tested? Yes No 1.5 Have the charger output and battery terminal voltage been tested? Yes No 1.6 Has the battery fault circuit been tested? Yes No 1.7 Is the system free of earth faults? Yes No 1.8 Are the engineer’s test switches and indicators operational? Yes No 1.9 Has the detection circuit monitoring been tested? Yes No 1.10 Has the sounder circuit monitoring been tested? Yes No 1.11 Is the control panel fully operational? Yes No 1.12 Are the visual and audible alarms (first stage) functioning correctly? Yes No 1.13 Are the repeater panels functioning correctly? Yes No

2 Extinguishing system

2.1 Are status indicators and remote lock-off units functioning correctly? Yes No 2.2 Is the agent hold-off unit properly installed and identified? Yes No 2.3 Is the gas release unit properly installed and identified? Yes No 2.4 Are the duty selector switches properly installed and identified? Yes No 2.5 Has the pressure switch circuitry been tested? Yes No 2.6 Has the second stage audible alarms been tested? Yes No 2.7 Has the second stage sounder circuit monitoring been tested? Yes No 2.8 Have the ancillary relays been tested? Yes No 2.9 Are all the ancillary relays operating correctly? Yes No 2.10 Is the system marking and documentation in accordance with the Pressure

Equipment Directive? Yes No



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3 Functional test 3.1 Has each detection circuit been tested and a correct response received? Yes No 3.2 Have the manual gas release units been operated and both stages

functioning correctly? Yes No

3.3 Have the agent hold-off units been operated and the system reverted to first stage?

Yes No

3.4 Have the firing circuits been energised and checked? Yes No 3.5 On initiation of primary power loss, did the system operate correctly? Yes No 3.6 Were fire and fault signals received by the remote monitoring station? Yes No

4 Condition of site 4.1 Has a check been made for any changes to the protected area/enclosure

since the installation was completed? Yes No

4.2 Is the area clean and dust free? Yes No 4.3 Have all other trades completed their work in the protected

area/enclosure? Yes No

4.4 Have all the voids been cleaned out and sealed? Yes No 4.5 Is the air conditioning system fully operational? Yes No 4.6 Are the ventilation systems fully operational? Yes No 4.7 Is the power distribution system live? Yes No 4.8 Has the fan pressure test been carried out? Yes No 4.9 Has the rectification works been carried out (if the pressure test failed)? Yes No 4.10 Has the fan pressure retest been carried out? Yes No

5 Testing of other services 5.1 Was the mechanical engineer present for the shut down of the air

conditioning and ventilation services systems during testing? Yes No

5.2 Was the pressure relief system tested and working correctly? Yes No 5.3 Was the agent extract system tested and working satisfactorily? Yes No 5.4 Was the electrical engineer present for the power shut down during

testing? Yes No

5.5 Was the building fire alarm engineer present for the testing, and the building fire alarm system tested?

Yes No

6 System status upon completion 6.1 Have the detector dust covers and other protection been removed? Yes No 6.2 Have panel keys been provided? Yes No 6.3 Was the system left operative/inoperative? Operative Inoperative 6.4 Was the system left in automatic mode/manual mode? Automatic Manual 6.5 Were the detectors left with/without dust covers? With Without

APPENDIX – FAX BACK


B

FAX BACK on FIRE EXTINGUISHING SYSTEMS – A GUIDE

TO THEIR INTEGRATION WITH OTHER BUILDING SERVICES SYSTEMS

Readers response

Please complete and return to: John Sands at BSRIA on 01344 487575

YES NO COMMENTS

The publication 1. Did you find this publication informative/useful?

2. Do you currently design and/or specify fire extinguishing systems?

3. Do you intend to apply the information outlined in this publication? If so, which specifically?

4. Are there any aspects of this topic you are aware of which have not been addressed in this publication?

Tailored guidance

5. Would it be useful to have an in-house presentation on

the integration of fire extinguishing systems with other building services systems?

Further work

6. Are you interested in supporting further research in

this subject area?

7. Are there any areas where you are seeking information and guidance which might form the subject of research or a new publication?

8. If you spotted any errors or omissions, we would be grateful if you could indicate the nature of the error and the relevant page/section number.

Name Initials Position

Company

Address

Post Code

Telephone

Fax

for FREE full BSRIA Publications Catalogue please tick here

BSRIA Limited Old Bracknell Lane West, Bracknell, Berkshire RG12 7AH T: + 44 (0)1344 426511 F: + 44 (0)1344 487575 E: [email protected] W: www.bsria.co.uk

APPENDIX - FAX BACK B

Training CoursesWhether it’s training in basic firedetection design or specific issuessuch as Approved Document B, thecourses offer a practical approachwhich has a real and tangible benefitin the workplace.

Flexibility is also key with coursesstaged at venues throughout thecountry to minimise travelling timeand costs.

And now the scheme also includesthe new DEFRA recognisedCompetence Certificate Coursedesigned to provide technicians withtraining and certification for thedecommissioning of Halon.Successful candidates will becomeregistered BAFE technicians,providing a real commercialadvantage for those seeking to workin this area.

More information on the full range ofcourses, along with an on-linebooking facility, is available on theBFPSA website:

The British Fire Protection Systems Association. Neville House 55 Eden Street Kingston upon Thames Surrey KT1 1BW England. Tel: 020 8549 5855 Fax: 020 8547 1564 Email: [email protected]

CPD provider, as listedin the CIBSE Directory(Continuing Professional Development)

Courses based on the relevantBritish and European Standards

Make sure YOU keep up-to-datewith the latest developments

www.bfpsa.org.uk

Fire Risk Assessment Catering Extract ventilation

by Stephen Loyd, BSRIA

For further information or to order,

contact BSRIA bookshop on +44 (0)1344 426511 or visit www.bsria.co.uk

By following this assessment and reducing the identified hazards, you will:

Prevent the build-up of grease deposits within the kitchen extract ventilation, which will reduce the risk of spreading fire, the growth of bacteria and odour, and improve airflow through the kitchen.

Reduce fire risks which will avoid the

associated business loss and liabilities in the event of a fire.

As an added benefit it will be easier to

get affordable insurance.

2002 fire extinguishing system-guide to their integration with other building services

Documents