Triangle of Fire & Active vs Passive Fire Protection

The ‘Combustion Triangle’ or ‘Fire Triangle’ is a simple model illustrating that in order for fire to exist, three elements are required – Oxygen, Heat and Fuel. It therefore means in order to prevent or extinguish a fire, removing any one of these components would do it.

When these three elements are combined at the right mixtures, a fire will naturally occur. However, a fire can be prevented from igniting or a fire that is already burning extinguished by removing any single one of these elements:

• Removing the fuel element
• Excluding the oxygen
• Removing the source of heat

PASSIVE FIRE PROTECTION

Passive Fire Protection attempts to contain fires and limit/slow their spread throughout a building, through use of devices such as fire resistant walls, doors and floors. Unlike with active fire protection, passive fire protection systems do not require turning on, or power, gas or water to operate. They are always ‘on’ (cannot be turned ‘off’) and are inherent to the structure of a building. In the event of a fire, passive fire protection systems can contain the spread of both fire and smoke.

ACTIVE FIRE PROTECTION

Active Fire Protection devices and systems are reactive and require a certain amount of motion and response in order to work. This type of fire protection is installed additionally to the structure of a building. There are two types of active fire protection:

• Fire Suppressants – These devices and systems are used to control or extinguish a fire that has already ignited. Examples of active fire suppressants include fire extinguishers, sprinkler systems and gaseous cleaning agents.
• Fire Detectors – These devices and systems detect the existence of a fire by locating the smoke, flame or heat, and an audible alarm is sounded to alert people to evacuate the building.