A fire suppression system is a fixed system designed to control and extinguish fires. The most common fire suppression systems are sprinkler systems, designed to automatically activate when smoke or fire are detected. Other types of fire suppression systems use chemicals or gases to disrupt the chain reaction that keeps fires burning, or deprive fires of the heat or oxygen they need to survive.
Fire Sprinkler Systems
Sprinkler systems are the most widespread type of fire suppression system, and for good reason: water is an inexpensive and, in most cases, highly effective means of putting out fires.
There are two broad types of sprinkler system. Most common are wet pipe systems, in which the pipes are filled with water at all times. When the system detects a fire, the heads activate, immediately dousing the fire. There are also dry pipe systems, in which the pipes only fill with water once the system is activated. That way, the pipes won’t freeze if the building goes unheated in the winter months.
Sprinkler systems come in even more specific varieties. A deluge system is a dry pipe system, in which all the sprinkler heads stay open. When the sprinkler system activates, water enters the pipes and all the sprinklers go off at once.
A pre-action sprinkler system is a dry pipe system in which a pre-action valve controls when water enters the system. The sprinkler heads themselves must also release individually. This combination makes it harder for the system to activate by accident, making pre-action systems especially useful for places where water can damage sensitive documents or computer systems.
Even though water is a highly cost-effective way to suppress fires, there are environments where it can make a fire worse or cause serious damage. In contexts ranging from restaurant kitchens to server rooms to factories, chemical and gas agents are the preferred means of fighting fires.
Chemical-Based Fire Suppression Systems
Chemical agents are the fire suppression method of choice in many environments. Restaurant kitchens, for instance, often use wet chemicals that can quickly put out grease fires, while also requiring less cleanup than water-based sprinkler systems.
Industrial plants that handle hazardous materials will often use dry chemicals to suppress fires. A museum filled with precious art might also use dry chemicals to ensure the artwork does not get damaged.
Chemical agents come with two key advantages over water-based sprinkler systems. For one, fire suppression chemicals do not conduct electricity, making them much safer to use around sensitive electronic equipment. For another, these chemicals cause less damage and create less mess than sprinkler systems.
Some chemical agents are better than others for the environment. For decades, halon was the chemical of choice for fighting fires. But because it depletes the ozone, new production of halon was banned in 1994. Since then, new fire suppressant chemicals have been developed, many of which have minimal impact on global warming.
Gas-Based Fire Suppression Systems
Other fire suppression systems use inert gases to deprive fires of the oxygen they need to survive. Many use carbon dioxide, which is highly effective at suffocating fires – and people, as well. For this reason, carbon dioxide systems only make sense in places where no people are present, such as server centers.
Other gas-based systems use nitrogen, argon, or a combination of fires to shut down combustion.
Fire Suppression Systems in Practice
Many businesses will use multiple types of fire suppression system to cover different environments. A restaurant, for instance, might use a chemical-based system in the kitchen in case of grease fires, while using a sprinkler-based system in the dining areas. An office complex, on the other hand, might rely on sprinkler systems in most areas, while implementing a carbon dioxide system in unmanned server rooms.
Of course, a fire suppression system on its own is far from the last word on fire safety. Tools such as fire extinguishers and smoke alarms, as well as evacuation plans and other policies, are just as critical in the event of a fire.
Security systems can often complicate fire safety – and vice versa. One of the key goals of security systems is to prevent unauthorized access. In the event of a fire, however, these systems must make way for everyone to evacuate the building as quickly as possible. In areas that use carbon dioxide-based fire suppression systems, you must also ensure anyone present can get out before the systems flush the environment with gas.
At the same time, you need also guard against any intruders that attempt to sneak in while your security systems are relaxed to allow for evacuation. In this case, you must find the difficult balance between perimeter security and fire safety.