What is the minimum flow density required for sprinkler coverage in NFPA 13R practice?

• A. 0.1 gpm/ft2 (4.1 mm/min)
• B. 0.2 gpm/ft2 (8.2 mm/min)
• C. 0.15 gpm/ft2 (6.1 mm/min)
• D. 0.05 gpm/ft2 (2.0 mm/min)

Answer: (A)

Flow density is how much water is delivered per unit area to the protected space. For NFPA 13R practice in low-rise homes, the minimum coverage density is 0.1 gpm per square foot (about 4.1 mm per minute when spread evenly). This level provides practical residential protection without the higher densities required for commercial occupancies. Higher values, like 0.2 gpm/ft^2 or 0.15 gpm/ft^2, align more with NFPA 13 ordinary hazard requirements, while 0.05 gpm/ft^2 would be too low to protect typical home fires. So 0.1 gpm/ft^2 is the correct minimum.