The space defined as dead air space for detectors is typically located at what distance from any corner?

The space defined as dead air space for detectors is typically located at what distance from any corner?

• A. 6 inches
• B. 8 inches
• C. 12 inches
• D. 4 inches

Answer: (D)

Dead air space is the stagnant pocket of air that forms where walls meet the ceiling. Smoke tends to accumulate and move along the ceiling, but in that corner area air doesn’t circulate well, so smoke can be slow to reach a detector if it’s placed too close. To avoid this delay, detectors are mounted with a minimum clearance from corners. Four inches from any corner is the standard minimum distance, keeping the sensing chamber out of the stagnant zone while still positions high enough to catch rising smoke. Distances greater than four inches also work, but four inches is the typical minimum recommended to prevent dead air interference.

Dead air space is the stagnant pocket of air that forms where walls meet the ceiling. Smoke tends to accumulate and move along the ceiling, but in that corner area air doesn’t circulate well, so smoke can be slow to reach a detector if it’s placed too close. To avoid this delay, detectors are mounted with a minimum clearance from corners. Four inches from any corner is the standard minimum distance, keeping the sensing chamber out of the stagnant zone while still positions high enough to catch rising smoke. Distances greater than four inches also work, but four inches is the typical minimum recommended to prevent dead air interference.