Where must heat detectors be mounted on the ceiling in relation to the wall?

Heat detectors must be mounted on the ceiling at least 4 inches from the wall to ensure they function correctly and detect heat generated by a fire effectively. This distance is necessary to account for air currents and potential obstructions that could interfere with the detector's ability to sense temperature changes.

Mounting the detector too close to the wall could lead to inaccurate readings, as it may be affected by cooler air from the wall or other nearby obstacles, diminishing its effectiveness in detecting a fire event. Proper placement as outlined in the guidelines ensures that the heat detector can respond to the thermal energy of a fire source in the most accurate manner possible.