A fire sprinkler system is an active fire protection measure, consisting of a water supply system, providing adequate pressure and flow rate to a water distribution piping system, onto which fire sprinklers are connected. Although historically only used in factories and large commercial buildings, systems for home and small building are now available at a cost-effective price. Fire sprinkler systems are extensively used worldwide, with over 40 million sprinkler heads fitted each year. In buildings completely protected by fire sprinkler systems, over 99% of fires were controlled by fire sprinklers alone.
Sprinkler activation will do less damage than a fire department hose stream, which provides approximately 900 liters/min (250 US gallons/min). A typical sprinkler used for industrial manufacturing occupancies discharge about 75-150 liters/min (20-40 US gallons/min). However, a typical Early Suppression Fast Response (ESFR) sprinkler at a pressure of 50 psi (3.40 Bar) will discharge approximately 378 liters/min (100 US gallons/ minute).
In addition, a sprinkler will usually activate between one to four minutes, whereas the fire department typically takes at least five minutes to arrive at the fire site after receiving an alarm, and an additional ten minutes to set up equipment and apply hose streams to the fire. This additional time can result in a much larger fire, requiring much more water to extinguish.