Where should heat detectors be mounted on beam ceilings when the specified beam dimensions apply?

Where should heat detectors be mounted on beam ceilings when the specified beam dimensions apply?

• A. On the bottom of the beam
• B. On the top surface of the beam
• C. On the wall adjacent to the beam
• D. In the open space between beams

Answer: (A)

Mount heat detectors on the bottom surface of the beam. When the beam dimensions are specified, the intended protection pattern is built around having detectors in the space below the beam where the room air and heat plume are most representative of the occupied area. Placing the detector on the bottom of the beam keeps it within the protected volume and avoids being shielded by the beam itself, ensuring quicker and more reliable heat detection. Mounting on the top surface can put the detector closer to the ceiling and may be obstructed by the beam, delaying response. Placing detectors in the open space between beams or on the adjacent wall falls outside the designed coverage and can be affected by drafts or be out of the intended sensing zone.

Mount heat detectors on the bottom surface of the beam. When the beam dimensions are specified, the intended protection pattern is built around having detectors in the space below the beam where the room air and heat plume are most representative of the occupied area. Placing the detector on the bottom of the beam keeps it within the protected volume and avoids being shielded by the beam itself, ensuring quicker and more reliable heat detection.

Mounting on the top surface can put the detector closer to the ceiling and may be obstructed by the beam, delaying response. Placing detectors in the open space between beams or on the adjacent wall falls outside the designed coverage and can be affected by drafts or be out of the intended sensing zone.