ISO Needed Fire Flow

NFF = Ci × Oi × (1 + X + P) per the ISO Public Protection Classification; Ci = 18 × F × sqrt(A) by construction class. Rounded to 250 gpm; capped at 12 000 gpm.

NFF = Ci × Oi × (1 + X + P) where Ci = 18 × F × sqrt(A_eff). F per construction class (Frame 1.5 / Joisted masonry 1.0 / Noncombustible and Masonry-noncombustible 0.8 / Modified-FR and Fire-resistive 0.6). A_eff = footprint × min(stories, 3) for non-fire-resistive; footprint × 1 for fire-resistive. X = exposure factor by distance band (0.05-0.25). P = communication factor. Output rounded to 250 gpm; floor 500, cap 12 000 gpm.

ISO Public Protection Classification (PPC) Schedule by name. Cited by name only; the schedule's commentary is not reproduced.

ISO PPC Schedule licensed; class-factor table free in published fire-protection texts and at most state insurance department outreach.

Estimate. AHJ and licensed fire protection engineer govern.

Field names used by the API: area_ft2, stories, construction_class, occupancy_factor, exposure_distance_ft, F_factor, A_eff_ft2, Ci_capped, X_exposure, NFF_gpm

• Construction-class F table 1=1.5 / 2=1.0 / 3=4=0.8 / 5=6=0.6ISO PPC
• Cap on Ci 8000 gpm before X / P / Oi factorsISO PPC engineering practice
• Round increment / floor / cap 250 gpm / 500 gpm / 12 000 gpmISO PPC