Fire Suppression
Sprinkler Density (NFPA 13)
Density (GPM/sf) × area of application = the design discharge. Pick the hazard class to get NFPA 13's density/area curves.
FAQ
What's 'area of application'? +
The hydraulically most-demanding area assumed to operate simultaneously. Designers calculate the worst-case zone (usually farthest from the riser) using this area and density.
Why include hose allowance? +
NFPA 13 §11.2.3.1: fire department hose streams pull from the same water supply. Total demand = sprinklers + hose. Always factor it.
Is this a real hydraulic calc? +
No — it gives you the demand the system must meet at the base of the riser. Real hydraulic design uses Hazen-Williams loss + K-factor balancing per node. Use HASS or AutoSPRINK.