Distance between smoke detectors, nominal spacing, is ____ feet?

Distance between smoke detectors, nominal spacing, is ____ feet?

• A. 10
• B. 15
• C. 30
• D. 20

Answer: (C)

The main idea is to ensure coverage so smoke is detected quickly. Standard practice places smoke detectors so that no point in the protected area is farther than 30 feet from a detector. That makes the nominal spacing 30 feet. This maximum distance helps ensure prompt alarm since smoke has to travel at most 30 feet to reach a detector. In spaces with high ceilings or unusual shapes, you still aim for no point farther than 30 feet from a detector, so you may place detectors a bit closer to maintain coverage.

The main idea is to ensure coverage so smoke is detected quickly. Standard practice places smoke detectors so that no point in the protected area is farther than 30 feet from a detector. That makes the nominal spacing 30 feet. This maximum distance helps ensure prompt alarm since smoke has to travel at most 30 feet to reach a detector. In spaces with high ceilings or unusual shapes, you still aim for no point farther than 30 feet from a detector, so you may place detectors a bit closer to maintain coverage.