What are the Different Types of Automatic Fire Protection?

B. Turner

Automatic fire protection systems work to slow the spread of a fire without the need for manual assistance or activation. Once a fire or smoke alarm goes off, the system automatically begins to put out the fire, or slow its spread through the building. These automatic fire protection systems help limit property damage and often allow more people to exit the building, reducing the number of injuries or deaths. While most fire suppression systems are found in commercial structures, some building codes may require sprinklers or other protection devices in residences as well.

A fire sprinkler is designed to spray water to suppress a fire.
A fire sprinkler is designed to spray water to suppress a fire.

Wet sprinkler systems are the most common type of automatic fire protection system. They consist of water-filled pipes that run through the ceiling of a building, with sprinkler heads placed in the ceiling at specified intervals. Each head contains a fluid-filled bulb, which bursts when exposed to high temperatures, allowing the water in the pipes to flow from the head. Contrary to popular belief, only heads exposed to high temperatures will activate during a fire, which helps to limit property damage from water.

Every home should be equipped with a functioning smoke alarm.
Every home should be equipped with a functioning smoke alarm.

In a deluge system, all the heads work together to put out a fire. This type of automatic fire protection system consists of water-filled pipes activated by either smoke alarms or temperature gauges within the building. During a fire, all heads release water to douse the flames quickly and effectively. Deluge systems are most commonly found in high-risk facilities, such as chemical or industrial plants.

Some applications require a dry pipe, or pre-action, system instead. In a pre-action system, the pipes are filled with air rather than water. The system requires two separate signals before water will be released from each head. An initial smoke alarm or manual input alerts the system to fill the pipes with water. Once each head is exposed to sufficiently high temperatures, the bulbs burst to allow water to flow from the head.

Museums and libraries often rely on either a pre-action system or a chemical-based fire suppression technique. In chemical-based systems, the sprinkler heads release dry chemicals or gas to smother a fire. This limits water damage to sensitive or irreplaceable objects like paintings or books. This type of dry chemical sprinkler system often includes Halon gas, though Halon is generally being replaced by more eco-friendly products. Dry automatic fire protection systems may pose a health risk to occupants in some applications, and are typically found in unoccupied parts of a building.

A ground post indicator valve opens and closes a water supply to fire protection systems in a building.
A ground post indicator valve opens and closes a water supply to fire protection systems in a building.

You might also Like

Discussion Comments


@Ana1234 - That's true of most of the modern world, but there are still a lot of people who are living without fire protection equipment. Anyone living in an old house that isn't up to fire codes, or in an impoverished area where they can't afford to do things like replace smoke alarm batteries (and might not have ever had the education to teach them that is necessary) is still at risk.

And unfortunately, fire control is one of those things like disease control that relies on everyone doing their part to keep the whole community safe. It doesn't matter how many precautions you take if your neighbor doesn't do the same, since by the time their house is an inferno your sprinklers aren't really going to make much difference.

This is really something that needs to be applied universally in legislation, for everyone's sake.


@MrsPramm - We've come a long way in terms of protection from fire in even the last few decades. It used to be one of the main causes of death, particularly for workers, because everything, from building materials to clothing, was extremely flammable and there was no automatic fire protection anywhere.

It's a horrible death too. Fires are one of those things the modern world takes completely for granted, but we are so lucky to have systems in place that prevent it.


When I went to see the rebuilt Globe theater in London, it was actually kind of funny how resentful the tour guide was that they had had to include modern fire control measures like sprinklers in the design. They had been trying to get it as close to authentic as possible, to the point where it's actually a fairly uncomfortable place to see a play because the seats are all wooden and most of the audience has to stand in the open anyway.

But since the original Globe burned down, and the roof is essentially made of straw, while everything else is wood, I can't see why they would really object to some precautions against fire. There's a point where being too authentic is silly, and letting the new theater burn down just like the old one did is definitely at that point.

Post your comments
Forgot password?