What spatial requirement governs the placement of heat detectors near sidewalls?

When placing heat detectors near sidewalls, the requirement specifies that they must be installed no less than 4 inches away from the wall. This spacing is crucial for ensuring that the detector can accurately sense temperature changes caused by potential fires, as environmental factors like heat stratification can affect their performance if placed too close to obstacles such as walls. The 4-inch minimum distance allows for a more reliable detection range, ensuring that the heat detector has an unobstructed view for effective monitoring of ambient temperature changes. Proper installation according to this guideline contributes to operational efficiency and safety in fire detection systems.