Kitchen Fire Suppression Calculator

Wet chemical suppression systems (the kind required under UL 300 and NFPA 17A for commercial cooking lines) are sized by counting nozzles per appliance type, since each nozzle only protects a defined area or piece of equipment. This calculator assigns one nozzle per fryer, one nozzle per 4 linear feet of griddle or range, and — because charbroilers carry meaningfully higher fire risk from open flame and grease flare-ups — one nozzle per just 2 linear feet of charbroiler, twice the density of griddle coverage. It adds one plenum nozzle per 10 feet of hood length to protect the space behind the filters, plus a fixed single nozzle at the duct collar, since code requires duct protection regardless of hood size.

Agent volume is then tallied per nozzle type rather than as a flat rate: fryer and charbroiler nozzles are budgeted at 2.0 gallons each (higher-hazard appliances need more agent), griddle nozzles at 1.5 gallons, and plenum/duct nozzles at 1.0 gallon each. That total gallon figure is matched to the smallest standard tank size that covers it (1.5, 3.0, 4.0, or 6.0 gallons); if the system needs more than 6 gallons of agent, the calculator switches to multiple 6-gallon tanks rather than one oversized tank, since 6 gallons is the largest common standard size. Piping length and manual pull station counts are rough estimates tied to hood length, and the cost estimate is a simple base-installation charge plus a per-nozzle cost — useful for ballpark budgeting, but any real installation should be quoted against actual equipment layout and local fire code by a licensed fire suppression contractor, since this is a planning estimate, not a certified design.