Fire detection systems

Fire detection systems

Fire detection systems are denoted by the size of a building, building construction, planning requirements, etc. Some things though are mandatory. Below, we’ve tried to explain as many systems as possible.

Internal smoke and heat detectors

Ever burnt the toast and suddenly the whole world seems to be filled with screeching alarms? Annoying, but it’s for your protection. By law, all apartments now have to have smoke detectors. These are hard-wired so that they have a power supply. There is then a battery in each detector so that should the power fail the alarm still works. Each detector is a unit in its own right so replacement is simple. The one other trick these units have as part of the wiring is they are linked together. If one is triggered, they all go off.

In kitchens now smoke detectors have been replaced with heat detectors. That way, if you burn the toast they don’t trigger, they only activate under the heat of a fire.

Building fire alarm panel

A lot of buildings will have a fire alarm system. This will normally have smoke detectors in a number of areas of the building such as corridors, car parks, and often electrical cupboards, etc. Some of these panels will be linked to the fire services so that if they trigger the fire brigade arrive. It is not a requirement for this to be the case.

This next bit will sound strange, but you will often find a fire alarm panel installed with no alarm bells (sounders) anywhere. If the panel detects smoke it will activate and, if connected, call the fire brigade. It may also be linked to other services such as smoke extraction systems, door locks, ventilation systems, etc. If the building has sounders, then the ‘stay put’ policy (as discussed in previous articles) would be void as people would continue to leave.

Building smoke extraction system

Some buildings will have smoke vents. These can be passive or mechanical. Mechanical ones have electric fans to draw air and passive systems operate normally by opening a window and allowing the smoke to vent naturally.

The idea behind this system is to allow smoke in a corridor to vent to the outside world. This means the corridors are safer to walk through (if required) in the case of a fire.

Building sprinkler system

These systems are being talked about more and more with the fire at Grenfell Tower in people’s minds. These systems are currently not found very often in existing apartment buildings. A sprinkler system has a number of heads in the apartment and these get activated under the excess heat of a fire. They then allow water to flow into the apartment, a little like a shower head, to kill the fire.

The downside is these systems are really messy and the fire damage they stop is then replaced by water damage. The plus point is no fire is much better. There are new systems on the market called mist systems. These produce a mist of water rather than the flood of water by a traditional sprinkler. They create less water damage and are as effective in most cases.