Fire sprinklers are the most advanced protection you can buy against home fires. But the technology at work is actually very simple. Here’s an overview of how fire sprinklers work.

A sprinkler head has no mechanical or moving parts; it’s essentially a plug made of heat-sensitive material designed to melt, shatter or dissolve when in the presence of extreme heat. Sprinkler heads are linked to pipes installed in the walls. With residential sprinkler systems, these pipes are usually filled with circulating water on a constant basis.

When a fire starts, it sends a jet of hot air towards the ceiling—often in excess of 68°C. A fire sprinkler head can be made from a substance that melts consistently at the appropriate temperature, a fusible material, or a glass bulb containing a liquid that will expand and shatter the glass in the presence of heat.  As soon as the fire starts, the heat-sensitive material melts or shatters, allowing the head to connect to pipes filled with water. The sprinkler head then douses the fire before it has a chance to grow out of control.

In movies and television, entire fire sprinkler systems are often depicted firing when a lighter or match is held beneath a sprinkler head. In actuality, it takes more than a match to set off a fire sprinkler system—and every sprinkler head must be activated individually. Most fires can be controlled by only one sprinkler head, and it’s very rare for every sprinkler head to be activated during a fire incident.  Approximately 90% of all residential fires can be controlled by a single sprinkler head.

Fire sprinkler systems are typically designed to release water droplets of a carefully controlled size—large enough to get to the core of a fire before they evaporate.  The water flow is strong enough to drop the core temperature of the fire below sustainable levels, effectively dousing it before it has a chance to spread much beyond the point of origin.

Fire sprinkler systems are designed to cover a certain range of space as well.  The space is meant to be large enough to assure that the water distribution is large enough to effectively control a fire big enough to set off the system—using only one sprinkler head. Typically, the water flow will continue until the fire sprinkler system is shut off by the fire brigade—a precaution taken to make sure the fire is entirely controlled.

Fire sprinkler systems are the strongest means of protecting your home against fire. Unlike other methods of protection, fire sprinklers work to control the fire long before firefighters arrive. In many cases, the fire is entirely extinguished before the fire brigade arrives. Unlike popular media portrayals, the heads in most fire sprinkler systems don’t go off all at once—and water damage is typically negligible and concentrated in the area where the fire started. In addition, malfunctions in fire sprinkler systems are extremely rare—approximately one in 500,000 fire sprinkler systems is estimated to malfunction as a result of a manufacturing defect. When it comes to protecting your home against fire, a sprinkler system is effective, unobtrusive and reliable—and the best option available.