Work out fire water storage instantly with clear inputs, formula shown and shareable results.
Fire water storage is the combined design flow of the systems assumed to operate together, sustained for the required duration. Codes specify which systems are additive: sprinklers and hydrants are usually combined, hose reels are added, and the duration ranges from thirty minutes for light hazard to two hours or more for high hazard storage.
Storage volume
Litres = (sprinkler flow + hydrant flow + hose reel flow) x required duration in minutes
Preliminary estimate only. Fire water demand and storage must be determined by a qualified fire protection engineer to the applicable code.
Litres = (sprinkler flow + hydrant flow + hose reel flow) x required duration in minutes. Fire water storage is the combined design flow of the systems assumed to operate together, sustained for the required duration.
That is the conservative and commonly required assumption. Some codes allow the hydrant demand to be reduced where sprinklers are installed, on the basis that sprinklers control the fire before manual attack begins.
This calculator takes 4 inputs: Sprinkler design flow, Hydrant design flow, Hose reel flow, Required duration. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.