Gaseous fire suppression
, also called clean agent fire suppression, is a term to describe the use ofinert gasesand chemical agents to extinguish afire. These agents are governed by theNational Fire Protection Association(NFPA) Standard for Clean Agent Fire Extinguishing Systems – NFPA 2001 in the US, with different standards and regulations elsewhere. The system typically consists of the agent, agent storage containers, agent release valves,fire detectors, fire detection system (wiring control panel, actuation signaling), agent delivery piping, and agent dispersion nozzles. Less typically, the agent may be delivered by means ofsolid propellantgas generatorsthat produce either inert or chemically active gas.
There are four means used by the agents to extinguish a fire. They act on the "fire tetrahedron":
- Reduction or isolation of fuel. No agents currently use this as the primary means of fire suppression.
- Reduction of heat. Representative agents:Clean agent FS 49 C2(NAF S 227, MH227, FM-200),Novec 1230,pentafluoroethane(NAF S125, ECARO-25).
- Reduction or isolation of oxygen: Representative agents: Argonite / IG-55 (ProInert),CO
2carbon dioxide,Inert Gas 541IG-541 Inergen, and IG-100 (NN100).
- Inhibiting the chain reaction of the above components. Representative agents:FE-13,1,1,1,2,3,3,3-Heptafluoropropane,FE-25,haloalkanes,bromotrifluoromethane,trifluoroiodomethane, NAF P-IV, NAF S-III, NAF S 125, NAF S 227, and Triodide (Trifluoroiodomethane)
Broadly speaking, there are two methods for applying an extinguishing agent: total flooding and local application:
- Systems working on a total flooding principle apply an extinguishing agent to a three dimensional enclosed space in order to achieve a concentration of the agent (volume percent of the agent in air) adequate to extinguish the fire. These types of systems may beoperated automaticallyby detection and related controls or manually by the operation of a system actuator.