Will All Fire Sprinklers Go Off Simultaneously and Flood My Home?

You’ve seen it in the movies. A lighter held up to one sprinkler sets off the entire fire sprinkler system, floods the place with water and causes everyone to evacuate (usually so someone can escape the building undetected).

It makes for a nice Hollywood scene, but this isn’t how a home fire sprinkler system actually works. Here’s the truth behind the myth.

Individual activation

Each sprinkler must be activated by the fire, so only the sprinklers closest to the fire will spray. The rest of your property will remain dry. In fact, most residential fires are controlled by just one sprinkler head. The rest of the fire sprinkler system is never activated because the heat from the fire doesn’t reach those sprinklers.

How it works

Most fire sprinkler system sprinkler heads feature a metal link or small glass bulb that is filled with heat-sensitive liquid. Once the air around the sprinkler head heats to a certain temperature (between 135° F and 650° F), the bulb expands or the link melts, allowing the sprinkler head to open and water to flow. Note: Steam or smoke from cooking will not provide enough heat to trigger a fire sprinkler. You don’t need to worry about flooding your home if you burn dinner.

Types of systems

There are three main types of home fire sprinkler systems. Each has a similar operation with some distinct features.

Wet pipe systems are the most common fire sprinkler system. In these systems, the pipes are constantly filled with water. Once the heat activates a sprinkler, it immediately releases water; however, only the sprinkler head that was activated will spray. Again, your entire fire sprinkler system will not release water and flood your home.

Dry pipe systems are often found in structures where the pipes will be exposed to freezing temperatures, such as a parking garage or walk-in refrigerator. In these systems, the pipes are not filled with water; instead, they are filled with nitrogen or pressurized air. Once the system is activated, the air pressure drops, a valve opens and water flows into the pipes and out through the sprinklers. Again, the water will only flow out of the activated sprinklers, not the entire home fire sprinkler system.

Deluge systems are the rare exception to this rule. These systems have pipes that are all open to each other and the sprinklers are also open. There is no heat sensor on each sprinkler head to trigger water flow. Instead, one releasing panel is connected to the entire fire sprinkler system. A smoke detector, heat detector or other sensor can trigger this panel, which releases a deluge valve. This sends water out of all the sprinklers at once—but these systems are only used in hazardous areas that might require a deluge of water, such as power plants or chemical storage facilities.

Have more questions?

If you have more questions about home fire sprinkler systems, contact the specialists at Carpet Capital Fire Protection Inc. We’ll help you choose the best fire sprinkler system for your property to keep your home safe. Reach us today at 706-278-2320.