Only the Sprinkler Closest to the Fire Will Activate, Spraying Water Directly on the Fire
Fire sprinklers are individually heat-activated and connected to a network of copper or steel pipe with water under pressure. When the heat of a fire raises the sprinkler to its operating temperature, usually between 135°-175°F, a fusible link or glass bulb will activate only that sprinkler over the fire, thereby releasing water only over the source of heat.
Home fire sprinklers are technologically very advanced, but the basic way they work is very simple. Fire sprinklers have no moving parts and act simply as a water plug that releases at a particular temperature.
How They Work
Watch this short animated movie that explains the workings of home fire sprinklers.
Courtesy of the Home Fire Sprinkler Coalition (HFSC)