The facts about sprinklers

A residential sprinkler system is a series of pipes (plastic or copper) and water spray heads designed to detect, intervene and suppress/control a fire when activated. One of the biggest advantages of fire sprinklers as a fire fighting tool is their simplicity. Fire sprinklers were invented more than 140 years ago and although their materials have since been refined, the way they work is unchanged.

How residential sprinklers operate

Residential sprinklers are individually heat-activated. They are connected to a network of piping which in turn is filled with water under pressure. When the heat of a fire raises the sprinkler to its operating temperature, usually between 57°C-79°C, a fusible link or glass bulb will activate only that sprinkler over the fire, thereby releasing water over the source of heat and walls, reducing the fire-size temperatures and levels of toxic gases within the room of origin

The result is to keep a fire from reaching potentially dangerous and life-threatening proportions and giving early detection. Residential sprinklers operate automatically in the event of a fire, even if the householder is not home, releasing water directly over the source of heat and sounding the alarm. They help to extinguish a fire, but should this not happen the system will control the fire and slow its growth and reduce smoke and toxic fumes. This means that the fire service will be faced with a less severe fire and much less damage caused to the property. Most importantly the householder will have had time to escape.

Sprinklers explained

Fire sprinklers spray water onto a fire while it is still small. The fire then cannot spread and is often extinguished. To make sure this happens, fire sprinklers are fitted in the ceiling at a regular spacing throughout a building and connected to a water piping network that is constantly filled with water under pressure. Each fire sprinkler is held closed by a thermal element. This is usually a small glass bulb filled with a type of alcohol. When there is a fire below the fire sprinkler, the heat makes the alcohol inside the glass bulb expand, just as it does in a thermometer. At a set temperature there is no more room for the alcohol to expand and so it breaks the bulb. The water seal then falls away and the sprinkler starts to spray water onto the fire below. Only the sprinklers above the fire will operate and none of the sprinklers reacts to smoke, such as from cooking. Most fires are controlled by one or two sprinklers.