How do fire sprinklers work?
Each sprinkler head contains a valve that opens to release water when a heat-sensitive element reaches a pre-determined temperature. Usually this will be at least 68°C, however, sprinkler heads that operate between temperatures of 57–230°C are also available.
Sprinkler heads are located at ceiling height (or in racks or on walls depending on the type of premises protected) – around one for every 9–15m² – and connected to a water supply. Once a sprinkler head has been activated it delivers water directly onto the fire, dousing the flames and reducing the spread of fire.
What do they look like when installed? Can they be concealed?
Sprinklers can easily be recessed and disguised with a cover plate, which is soldered to the sprinkler at three points. When exposed to heat from a fire, the cover falls away and the sprinkler is exposed and able to operate.
Can fire sprinklers only be installed in new buildings?
No, sprinklers can be retrofitted into almost any kind of building – even listed or historic premises.
Are sprinklers activated by smoke?
Fire sprinklers do not respond to smoke, dust, fumes from aerosol sprays or steam.
How reliable are fire sprinklers?
Fire sprinklers are arguably the most robust and reliable fire safety device in today’s market. 96% of fires in sprinkler-protected buildings are controlled or extinguished by the system on the premises.
Do sprinklers ever go off accidentally?
It is an extremely rare occurrence for a properly maintained sprinkler system to discharge accidentally. Records indicate that the possibility of a sprinkler accidentally activating is in the region of 16 million to one. You have more chance of being hit by a meteor.
Are there insurance benefits for installing a fire sprinkler system?
Insurance companies welcome premises with a fire sprinkler system installed. You can expect many to offer lower insurance premiums for the added increase in safety against fire. Discounted premiums can reach up to 60%.
How much do they cost?
On average, for an industrial building the cost will be between £33 per square metre and £35 per square metre*, but to minimise costs, sprinklers should be designed into building plans. *BRE Appendix G,G1, Page 63
Are sprinklers expensive to maintain?
Unlike other fire protection systems which usually depend on electronics, sprinkler systems need only very basic maintenance.
Usually two visits each year by the installation company will suffice. Simple weekly and monthly checks of pumps (where fitted), pressure gauges and valve settings can be carried out by a trained employee.
Doesn’t a fire detection system provide enough protection?
Fire detection systems (including domestic smoke alarms) save lives by providing a warning of fire, but can do nothing to control or extinguish a growing fire.
Won’t water damage from a fire sprinkler system be more extensive than fire damage?
An Automatic Fire Suppression System (AFSSS) prevents large fires by controlling or extinguishing a fire before the Fire and Rescue Service (FRS) arrive. By controlling or extinguishing a fire at source, not only is any water damage from the AFSS minimal in comparison to the damage the fire would have caused, but also water damage from a fire sprinkler system will also be far less severe than the damage caused by water from firefighters’ hoses.
When one sprinkler goes off, won’t they all go off?
Only the sprinkler heads in the immediate vicinity of a fire will operate. Research carried out over 20 years shows that 80% of fires are controlled or extinguished by the operation of fewer than six sprinkler heads.
Aren’t sprinkler systems impractical in cold climates as the pipes will freeze and cause water damage?
The sprinkler installation standards include a range of measures which can be incorporated in systems to prevent low temperatures impacting on the operation of sprinklers should there be a fire.