High pressure water mist is a highly efficient fire suppression system which uses specially designed nozzles to create a fine mist. Where high pressure water mist shows its real advantage is that it combines the fire suppression effect of gas systems (by preventing fresh oxygen reaching the seat of the fire) and traditional sprinkler systems (more efficient way of cooling the fuel / material), using much less water in the process.
A fire relies on the presence of three elements in order to survive: oxygen, heat and combustible material. This is commonly known as the fire triangle. Unlike traditional sprinkler systems, which only remove heat, water mist systems deliver fire suppression by removing both heat and oxygen from a fire by jetting water at high, medium or low pressure through specially designed nozzles. The nozzles atomise the water into micron-sized droplets, which rapidly expand into steam when they come into contact with a fire, depriving the fire of oxygen. In addition, water mist has a cooling effect on the surrounding area, which prevents re-ignition of the fire source and any other material that may have caught fire.
Water mist fire suppression is not a new technology, it has been around since the 19th century, and has proved its effectiveness in maritime applications where it has been responsible for saving countless lives. It did not become widely used in land-based applications until the 1970’s when the Montreal protocol banned the use of halon gas as a fire suppressant. The technology was more widely adopted following the 1990 Scandinavian Star Disaster.