Fire sprinklers are individually heat-activated and connected to a network of water pipes. When the heat from the fire plumes hot gases reach the sprinkler and at a specific temperature (usually about 68 deg. C) that sprinkler activates delivering water directly to the source of the heat.
A fire starts small. If detected and tackled early enough a fire can be controlled with very little water. Fire sprinklers operate automatically even if you are not at home releasing water directly over the source of the fire and sounding the alarm.
Records from Australia and New Zealand (where all fires must be reported) between 1886 and 1986 show that sprinklers controlled 99.7% of all fires where they were fitted.
Records in service show that sprinklers are very dependable. The chance of an accidental discharge is 16000000:1 – less than your chance of winning the lottery!
Sprinklers are NOT expensive; normally costing around 1-2% of the cost of construction of a new building. The use of sprinklers will usually allow design freedoms as well, which can reduce construction costs and improve usability of the building.