Spot-type heat detectors may be installed on which surfaces? If mounted on the ceiling, they must be at least how many inches from the side wall?

Spot-type heat detectors may be installed on which surfaces? If mounted on the ceiling, they must be at least how many inches from the side wall?

• A. 2 inches
• B. 4 inches
• C. 6 inches
• D. 8 inches

Answer: (B)

Spot-type heat detectors sense heat from the surrounding room air, so their location needs to provide unobstructed delivery of air to the sensing element. When you mount one on the ceiling, keeping it at least four inches away from the side wall helps ensure the detector isn’t affected by the wall’s boundary layer, drafts, or heat from the wall itself. This spacing reduces the chance of delayed or inaccurate readings and promotes a quicker, more reliable response to heat buildup in the room. These detectors can be installed on ceilings or on walls, but for ceiling mounting the four-inch distance from the side wall is the important rule.

Spot-type heat detectors sense heat from the surrounding room air, so their location needs to provide unobstructed delivery of air to the sensing element. When you mount one on the ceiling, keeping it at least four inches away from the side wall helps ensure the detector isn’t affected by the wall’s boundary layer, drafts, or heat from the wall itself. This spacing reduces the chance of delayed or inaccurate readings and promotes a quicker, more reliable response to heat buildup in the room. These detectors can be installed on ceilings or on walls, but for ceiling mounting the four-inch distance from the side wall is the important rule.