Where is the correct location to mount a heat detector on a beam ceiling when the beams are less than 12 inches in depth and less than 96 inches on center?

Where is the correct location to mount a heat detector on a beam ceiling when the beams are less than 12 inches in depth and less than 96 inches on center?

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

Answer: (C)

In a beam ceiling, the heat detector should be mounted on the bottom surface of the beam. This places the sensing element in the same air space as the room and in the path where heat and smoke rise into the ceiling, giving quick and reliable detection across the open bay between beams. If you put the detector on the top surface, it sits against the beam and can be shielded by the beam itself, delaying response. Installing it in the open space above the beam can create dead-air pockets and reduce effective sensing in the occupied space. Mounting on the wall misses the ceiling area where heat typically accumulates first, so it provides poorer coverage.

In a beam ceiling, the heat detector should be mounted on the bottom surface of the beam. This places the sensing element in the same air space as the room and in the path where heat and smoke rise into the ceiling, giving quick and reliable detection across the open bay between beams. If you put the detector on the top surface, it sits against the beam and can be shielded by the beam itself, delaying response. Installing it in the open space above the beam can create dead-air pockets and reduce effective sensing in the occupied space. Mounting on the wall misses the ceiling area where heat typically accumulates first, so it provides poorer coverage.