Fire Detection and Alarm Systems
Updated: Mar 26, 2018
A fire in your premises must be detected quickly and a warning given, allowing people to
escape safely. Fire can be detected by people and manual fire detection may be all that is required. However an automatic fire detection and alarm system is normally considered necessary in the following buildings/ situations:
• Buildings in which people sleep
• Covered shopping complexes and large or complex places of assembly
• Buildings with phased evacuation
• In compensation for a reduction in standards of certain other fire protection measures (e.g. extended travel distance or reduction in the fire resistance of construction protecting the escape route)
• In lieu of vision between an inner room and its associated access room
• As a means of automatically operating other fire protection measures such as closing fire doors, the release of electronically locked doors or initiation of smoke control systems
An appropriate FD&A system will warn everyone in the building at the earliest opportunity so that they can exit the building or follow other instructions that are issued, and to also alert the Fire Brigade to allow early intervention. The FD&A system may be connected to other systems or equipment for the automatic control of fire protection measures, e.g. fire dampers or fixed extinguishing systems.
Different types of fire detector are suitable for different parts of your premises. Before installing an FD&A system, discuss your proposals with an appropriately qualified and experienced specialist.
Fire alarm systems should be installed by companies certified to either LPS1014 or SP203-1 third party certification schemes which prove their competence in that area.
FD&A systems installed in commercial premises should be designed, installed, tested and maintained in accordance with BS 5839-1 recommendations.
Systems can vary from small simple systems with one or two manual call points and sounders to systems which incorporate a large number of automatic fire detectors, manual call points and sounders connected to numerous intercommunicating control and indicating panels.
Systems may also be designed to include sophisticated techniques to avoid false alarm.
Various audio and visual alarm systems are available to manage the controlled evacuation of a building in the event of a fire.
A wide range of equipment is available that will cater for the FD&A requirements of any type of premises.
The types of equipment recommended may include some of the following range of products:
• All systems will include manual call points that allow people to raise a fire alarm, commonly known as “break glass” units
• Point detectors are designed to detect one or more of the four characteristics of fire; heat, smoke, combustion gas (i.e. carbon monoxide), or radiation (i.e. infra-red or ultra violet)
• Multi-sensor detectors combine detector technology to improve the detection characteristics and reject false alarms
• Optical beam detectors provide economical and effective protection of large, open plan spaces where the use of traditional detection technologies would prove to be difficult and/or costly to install
• Line type heat detectors are used in large industrial spaces such as tunnels or car parks with adverse environmental conditions
• Aspirating smoke detectors are traditionally associated with early warning, high sensitivity applications such as the protection of computer rooms but they are also widely used to provide flexible and discrete detection solutions – for example in inaccessible, harsh, unusually high or aesthetically sensitive areas
• Sounders and bells give an audible fire alarm warning but these may be supplemented by voice alarm devices that give spoken instructions, or even a sophisticated voice alarm system
• Wireless systems are available which provide solutions where wired installations are not suitable
• Other devices, such as visual alarms or beacons,are used if there is a risk of audio signals not being adequately heard by all occupants, either for disability reasons or by use of ear defenders.
The operation of all this equipment is coordinated and controlled by a control and indicating panel. This piece of equipment allows the day to day test and running of the fire alarm system but is also at the centre of managing what happens in the event of a
The control and indicating panel may indicate only the zone in which a detector or call point has been activated or it may be a fully addressable panel giving details and location of the individual detector or call point that has operated.
There should always be a zone plan displayed alongside the fire alarm control and indicator panel.