Addressable vs conventional fire alarm system
The key to an effective fire alarm system is that it meets the requirements of the building it’s protecting. From high-rise, to warehouse, to small office block, each building will have one of two systems: addressable or conventional.
Let’s look at addressable first.
Addressable fire alarm system
An addressable fire alarm system is wired on a loop. The loop configuration means all fire and smoke detectors are connected back to a central control panel which monitors the detection on the loop 24/7. When one of the devices goes into ‘fire’ the panel receives information which helps the fire service find the location as quickly as possible. Each of the detectors is numbered and each area of the building is assigned a zone so the communication might, for example, run like this: detector number 10 goes into fire, the central control panel communicates ‘device 10, loop 1, zone 10’ and a description of the zone. When the fire service arrive they can use the zone plan, which must be installed by law next to the panel, to find the exact location of the fire and inform their route to the zone. Without this information they would be putting their own lives at risk to find the fire floor by floor.
The type of fire alarm system works particularly well in buildings such as tower blocks, hospitals and hotels. The system is fully programmable to the building’s bespoke requirements; it can operate a ‘one out, all out’ system where a full evacuation happens, or a phased evacuation can be implemented. This is where the larger commercial buildings really benefit; the alarm will only sound in the affected area and the only occupants who need to evacuate are those in that area. It prevents crushing and congestion in stairwells and inconvenience to other people using the building.
Top 3 benefits of an addressable system
- Response time – the pinpoint accuracy the control panel provides the fire service allows quicker management of a fire.
- Flexible – the system can be programmed to the building’s exact requirements and can easily be altered if there is a change of use in one of the zones.
- Ease of use – from the fire service to facilities management, an addressable system is easy to operate and communicates clearly with the user.
Conventional fire alarm system
Conventional systems are well suited to buildings such as smaller office blocks, shops and warehouses where the layout of the building is less complex. They work on the same principle as an addressable system in that automatic detection has a minimum and maximum distance between each detector, depending on layout and obstacles etc. Each floor is generally a zone and the number of detectors installed depends on the size of the building itself. The system is wired as a radial circuit with an end-of-line resistor on the last device. If a detector goes to ‘fire’ the alarm will sound throughout the building and a full evacuation will go into operation.
Once the fire service arrives, instead of a pinpoint location they would receive from the control panel of an addressable fire system, they are only made aware of which zone the fire is in. This might sound like a major drawback, but with fewer occupants, fewer rooms, and perhaps a zone that is more open plan, a fire can still be located fairly quickly. Equally, if there’s a fault on the system, the control panel will simply say ‘fault zone 1’, for example, which will slow the fault finding mission down, whereas and addressable system provides the exact device number and location.
Top 3 benefits of a conventional system
- Cost – the system as a whole costs less than and addressable system (although, due to the amount of wiring, installation time may bump up the cost).
- Effective – they’re perfectly effective and efficient for smaller applications.
- Simple – thanks to the basic nature of the system, the control panel is easy to understand and operate.
Whatever type of commercial building you operate, you do need a properly installed and maintained fire alarm system. If you’re unsure which would benefit you most, get in touch with a member of our team today.
Anthony Pritchard, Fire Design Project Manager, Zicam Integrated Security Limited.
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