A fire alarm horn strobe, pull station, and remote annunciator all connected together in a fire alarm system.

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A fire alarm notification appliance as widely used under North American standards.

A fire alarm system is a building system designed to detect and alert occupants and emergency forces of the presence of smoke, fire, carbon monoxide, or other fire-related emergencies. Fire alarms systems are required in most commercial buildings. They may include smoke detectors, heat detectors, and manual fire alarm activation devices, all of which are connected to a Fire Alarm Control Panel (FACP) normally found in an electrical room or panel room. Fire alarm systems generally use visual and audio signalization to warn the occupants of the building. Some fire alarm systems may also disable elevators, which under most circumstances are unsafe to use during a fire.[1]


After the fire protection is established—usually by referencing the minimum levels of protection mandated by the appropriate model building code, insurance agencies, and other authorities—the fire alarm designer undertakes to detail specific components, arrangements, and interfaces necessary to accomplish these goals. Equipment specifically manufactured for these purposes is selected and standardized installation methods are anticipated during the design.

Last version 2019; Status, Published. This code is part of a family standard NFPA

There are national codes in each European country for planning, design, installation, commissioning, use, and maintenance of fire detection systems with additional requirements that are mentioned on TS 54 -14

Across Oceania, there are Standards that outline the requirements, test methods, and performance criteria for fire detection control and indicating equipment (FDCIE) utilised in building fire detection and fire alarm systems.


A fire alarm control panel
Fire alarm speaker and pull station

Initiating devices

Fire alarm pull station

Notification appliances

Main article: Fire alarm notification appliance

A speaker and a remote light
A fire alarm notification appliance (Sweden)
A combined fire alarm/general alert notification appliance allows a single device to serve fire alarm and general emergency notification purposes.

Alarms can be either motorized bells or wall-mountable sounders/horns. They can also be speaker strobes that sound an alarm, followed by a voice evacuation message for clearer instructions on what to do. Fire alarm sounders can be set to certain frequencies and different tones including low, medium, and high, depending on the country and manufacturer of the device. Most fire alarm systems in Europe sound like a siren with alternating frequencies. Fire alarm electronic devices are known as horns in the United States and Canada and can be either continuous or set to different codes. Fire alarm warning devices can also be set to different volume levels.

As per NFPA 72, 18.4.2 (2010 Edition)Temporal Code 3 is the standard audible notification in a modern system. It consists of a repeated three-pulse cycle (0.5 s on, 0.5 s off, 0.5 s on, 0.5 s off, 0.5 s on, 1.5 s off). Voice Evacuation is the second most common audible in a modern system. Legacy systems, typically found in older schools and buildings, have used continuous tones alongside other audible schemas.

Emergency voice alarm communication systems

Mass notification systems/Emergency communication systems

Mass notification systems often extend the notification appliances of a standard fire alarm system to include PC-based workstations, text-based digital signage, and a variety of remote notification options including email, text message, RSS feed, or IVR-based telephone text-to-speech messaging.

Residential Fire Systems

Residential Fire Alarm Systems are also common place. Residential system code is a lot less strict then in commercial buildings. Typically residential fire alarm systems are installed as part of a security systems. In the United States, a residential fire alarm system is required if more then 12 smoke detectors are needed for the system. [19] Residential Systems are a lot less complex then commercial systems and have few parts compared to commercial systems.

Building safety interfaces

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Coded fire alarm pull station below a 10-inch (25 cm) bell

British fire alarm system categories

Fire alarm systems in non-domestic premises are generally designed and installed in accordance with the guidance given in BS 5839 Part 1. There are many types of fire alarm systems each suited to different building types and applications. A fire alarm system can vary dramatically in both price and complexity, from a single panel with a detector and sounder in a small commercial property to an addressable fire alarm system in a multi-occupancy building.

BS 5839 Part 1 categorizes fire alarm systems as:[21]

Categories for automatic systems are further subdivided into L1 to L5 and P1 to P2.

M Manual systems, e.g., handbells, gongs, etc. These may be purely manual or manual electric, the latter may have call points and sounders. They rely on the occupants of the building discovering the fire and acting to warn others by operating the system. Such systems form the basic requirement for places of employment with no sleeping risk.
P1 The system is installed throughout the building—the objective is to call the fire brigade as early as possible to ensure that any damage caused by the fire is minimized. Small low-risk areas can be excepted such as toilets and cupboards less than one square meter (11 sq ft).
P2 Detection should be provided in parts of the building where the risk of ignition is high and/or the contents are particularly valuable. Category 2 systems provide fire detection in specified parts of the building where there is either high risk or where business disruption must be minimized.
L1 A category L1 system is designed for the protection of life and which has automatic detectors installed throughout all areas of the building (including roof spaces and voids) with the aim of providing the earliest possible warning. A category L1 system is likely to be appropriate for the majority of residential care premises. In practice, detectors should be placed in nearly all spaces and voids. With category 1 systems, the whole of a building is covered apart from minor exceptions.
L2 A category L2 system designed for the protection of life and which has automatic detectors installed in escape routes, rooms adjoining escape routes and high hazard rooms. In medium-sized premises (sleeping no more than ten residents), a category L2 system is ideal. These fire alarm systems are identical to an L3 system but with additional detection in an area where there is a high chance of ignition (e.g., kitchen) or where the risk to people is particularly increased (e.g., sleeping risk).
L3 This category is designed to give early warnings to everyone. Detectors should be placed in all escape routes and all rooms that open onto escape routes. Category 3 systems provide more extensive cover than category 4. The objective is to warn the occupants of the building early enough to ensure that all are able to exit the building before escape routes become impassable.
L4 Category 4 systems cover escape routes and circulation areas only. Therefore, detectors will be placed in escape routes, although this may not be suitable depending on the risk assessment or if the size and complexity of a building are increased. Detectors might be sited in other areas of the building, but the objective is to protect the escape route.
L5 This is the "all other situations" category, e.g., computer rooms, which may be protected with an extinguishing system triggered by automatic detection. Category 5 systems are the "custom" category and relate to some special requirements that cannot be covered by any other category.


An important consideration when designing fire alarms is that of individual zones. The following recommendations are found in BS 5839 Part 1:

Also, the NFPA recommends placing a list for reference near the FACP showing the devices contained in each zone.

See also


  1. ^ Davis, Jemma (11 May 2018). "Lift safety in the event of a fire". Coopers Fire. Retrieved 12 July 2023.
  2. ^ ISO 7240-14:2013 | Fire detection and alarm systems — Part 14: Design, installation, commissioning and service of fire detection and fire alarm systems in and around buildings.
  3. ^ "CEN Community - List of members". standards.cencenelec.eu. Retrieved 26 March 2022.
  4. ^ "VdS Guidelines for Planning and Installation of Fire Protection Systems". VdS. Archived from the original on 29 January 2019. Retrieved 26 March 2022.
  5. ^ "UNI 9795:2013". store.uni.com (in Italian). Retrieved 26 March 2022.
  6. ^ "NF S61-936". Afnor EDITIONS (in French). Retrieved 26 March 2022.
  7. ^ "UNE 23007-14:2014". www.une.org (in Spanish). Retrieved 26 March 2022.
  8. ^ "Fire detection and fire alarm systems for buildings - Code of practice for design, installation, commissioning and maintenance of systems in non-domestic premises". shop.bsigroup.com. Retrieved 26 March 2022.
  9. ^ "AS 1603.4-1987 – Automatic fire detection and alarm systems - Control and indicating equipment". infostore.saiglobal.com. Retrieved 27 April 2023.
  10. ^ "AS 4428.1998 – Fire detection, warning, control and intercom systems - Control and indicating equipment Fire". infostore.saiglobal.com. Retrieved 27 April 2023.
  11. ^ "AS AS 7240.2:2018 – Fire Detection and Alarm Systems Fire detection control and indicating equipment (ISO 7240-2:2017, MOD)". infostore.saiglobal.com. Retrieved 27 April 2023.
  12. ^ Mariani, Michael (8 April 2020). "The Components Of A Commercial Fire Alarm System". Commercial Fire And Communications.
  13. ^ Chenebert, A.; Breckon, T.P.; Gaszczak, A. (September 2011). "A Non-temporal Texture Driven Approach to Real-time Fire Detection". Proc. International Conference on Image Processing (PDF). IEEE. pp. 1781–1784. doi:10.1109/ICIP.2011.6115796. hdl:1826/7588. ISBN 978-1-4577-1303-3. S2CID 11394788. Archived from the original (PDF) on 13 March 2020. Retrieved 8 April 2013.
  14. ^ Dunnings, A.; Breckon, T.P. (2018). "Experimentally Defined Convolutional Neural Network Architecture Variants for Non-temporal Real-time Fire Detection". Proc. International Conference on Image Processing (PDF). IEEE. Retrieved 9 August 2018.[permanent dead link]
  15. ^ National Fire Protection Association (February 2001). "Chapter 3 Fundamental Fire Protection Program and Design Elements". NFPA 805 Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants. National Fire Protection Association. standard: Gaseous Fire Suppression Systems 3.10.7.
  16. ^ National Fire Protection Association (2011). "Chapter 4 Annex A". NFPA 12 Standard on Carbon Dioxide Extinguishing Systems. National Fire Protection Association. standard: A.
  17. ^ Cote, Arthur E. (March 2000). Fire Protection Handbook eighteenth edition. National Fire Protection Association. pp. 5–8. ISBN 0-87765-377-1.
  18. ^ NFPA 72 – National Fire Alarm and Signaling Code – 2010 Edition. National Fire Alarm Association, 2009, Page 118, Subsection 24.4.1
  19. ^ "What's the maximum amount of hardwired smoke alarms I can install?".
  20. ^ "Fire Door Holders - Geofire". Geofire. Retrieved 21 March 2018.
  21. ^ "Fire Industry Association Fact File 0058". the Fire Industry Association ("FIA"). Archived from the original on 20 February 2015. Retrieved 20 February 2015.