Max Sprinkler Design Area for a Water Supply (NFPA 13)
The inverse of the sprinkler-demand tile: the largest hydraulic design area a water supply can serve at a density, once the hose allowance is taken off the top, max area = (supply - hose) / density. A 550-gpm supply with 250 gpm of hose at 0.20 gpm/ft^2 covers up to 1,500 ft^2; a lighter hazard (lower density) covers more. The area/density screen; a most-remote-area hydraulic calculation governs. A design aid; a fire-protection engineer and the AHJ govern.
Formula and source
sprinkler_gpm = available_supply_gpm - hose_gpm; max_design_area_ft2 = sprinkler_gpm / density. The NFPA 13 area/density demand solved for the area.
NFPA 13 (Standard for the Installation of Sprinkler Systems), 2022, by name, solved for the design area.
Audience
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Posture
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