Sprinkler systems have two main purposes: one, to extinguish unwanted fires; and, two, to control the size of a fire until trained fire suppression crews arrive to extinguish the fire. These are typically used in high-hazard areas, where the sprinkler system is directly connected to a dedicated water supply that when activated, a control valve releases water to the open sprinkler heads. A dry system that is not at risk of having frozen pipes offers a quicker response to fire by releasing water through all its open heads at once.