Heat detectors with a listed spacing of 50 feet placed on a smooth and flat ceiling which is 10 feet AFF. Based on this ceiling height, the heat detectors shall have a spacing of ____ feet between devices?

Heat detectors with a listed spacing of 50 feet placed on a smooth and flat ceiling which is 10 feet AFF. Based on this ceiling height, the heat detectors shall have a spacing of ____ feet between devices?

• A. 50
• B. 35
• C. 40
• D. 45

Answer: (A)

Heat detectors are spaced based on ceiling height and the way heat rises. On smooth, flat ceilings, the heat spreads horizontally, so the detector spacing is set to prevent a hot spot from developing between devices. At a ceiling height of 10 feet above the finished floor, the maximum recommended spacing is 50 feet. Since the detectors in question are listed for 50-foot spacing, they are appropriate for a 10-foot-high flat ceiling, ensuring full coverage. If the ceiling were higher, the spacing would have to be reduced to maintain the same level of coverage.

Heat detectors are spaced based on ceiling height and the way heat rises. On smooth, flat ceilings, the heat spreads horizontally, so the detector spacing is set to prevent a hot spot from developing between devices. At a ceiling height of 10 feet above the finished floor, the maximum recommended spacing is 50 feet. Since the detectors in question are listed for 50-foot spacing, they are appropriate for a 10-foot-high flat ceiling, ensuring full coverage. If the ceiling were higher, the spacing would have to be reduced to maintain the same level of coverage.