What can cause an automatic fire sprinkler system to trigger?

An automatic fire sprinkler system is designed to activate in response to certain physical conditions, primarily heat. When a fire occurs, the temperature in the vicinity of the fire increases significantly. Each sprinkler head is equipped with a heat-sensitive element, such as a glass bulb filled with a liquid that expands with heat. When the temperature reaches a predetermined level, this element breaks, allowing water to flow from the sprinkler head and suppress the fire.

The primary function of the sprinkler system is to respond directly to the heat generated by a fire, making it highly effective in extinguishing flames before they can spread. Since smoke does not directly cause the sprinkler to trigger and water pressure fluctuations or electrical malfunctions do not signal the presence of heat, they are not factors in the activation of the system. Thus, the correct cause for triggering an automatic fire sprinkler system is heat from a fire.