What is the typical area per sprinkler unit used to determine spacing?

What is the typical area per sprinkler unit used to determine spacing?

• A. 130 ft2 (12 m2) per unit
• B. 120 ft2 (11 m2) per unit
• C. 140 ft2 (13 m2) per unit
• D. 150 ft2 (14 m2) per unit

Answer: (A)

In NFPA 13R, spacing is determined by how much floor area each sprinkler is expected to cover. That design area per sprinkler sets how far apart heads should be placed so every area receives adequate coverage with the standard spray pattern. For typical low-rise residential systems, the standard design area per sprinkler is about 130 ft² (roughly 12 m²). So you layout sprinklers so each one is responsible for about 130 ft² of space, which corresponds to roughly an 11 ft by 11 ft area per head. The other values would change the coverage area per sprinkler and are not the commonly used design area for NFPA 13R.

In NFPA 13R, spacing is determined by how much floor area each sprinkler is expected to cover. That design area per sprinkler sets how far apart heads should be placed so every area receives adequate coverage with the standard spray pattern. For typical low-rise residential systems, the standard design area per sprinkler is about 130 ft² (roughly 12 m²). So you layout sprinklers so each one is responsible for about 130 ft² of space, which corresponds to roughly an 11 ft by 11 ft area per head. The other values would change the coverage area per sprinkler and are not the commonly used design area for NFPA 13R.