In light hazard installations, the maximum spacing between sprinklers is 15 feet.

In light hazard installations, the maximum spacing between sprinklers is 15 feet.

• A. 18 feet
• B. 12 feet
• C. 15 feet
• D. 21 feet

Answer: (C)

In light hazard installations, the goal is to achieve uniform water distribution with overlapping spray patterns so every point in the area is within reach of at least one sprinkler and meets the required water density. When sprinklers are arranged on a regular grid, the farthest point from any sprinkler sits at the center of a square formed by four sprinklers. That point is a distance equal to the grid spacing divided by the square root of two from the nearest sprinkler. With a 15-foot spacing, the farthest point is about 10.6 feet away, which aligns with the typical spray reach and coverage needs for light hazard. If spacing were larger, like 18 or 21 feet, the farthest points would be farther from the sprinklers and could fail to receive the required water density. Smaller spacing would increase the number of sprinklers and cost without a proportional benefit for light hazard. Therefore, 15 feet is the standard maximum to ensure reliable coverage while keeping design practical.

In light hazard installations, the goal is to achieve uniform water distribution with overlapping spray patterns so every point in the area is within reach of at least one sprinkler and meets the required water density. When sprinklers are arranged on a regular grid, the farthest point from any sprinkler sits at the center of a square formed by four sprinklers. That point is a distance equal to the grid spacing divided by the square root of two from the nearest sprinkler. With a 15-foot spacing, the farthest point is about 10.6 feet away, which aligns with the typical spray reach and coverage needs for light hazard. If spacing were larger, like 18 or 21 feet, the farthest points would be farther from the sprinklers and could fail to receive the required water density. Smaller spacing would increase the number of sprinklers and cost without a proportional benefit for light hazard. Therefore, 15 feet is the standard maximum to ensure reliable coverage while keeping design practical.