Can smoke detectors be installed above suspended ceilings or beneath raised floors for environmental air?

Smoke detectors are designed to detect the presence of smoke as an indicator of fire. For optimal performance, they should be installed in areas where they can effectively sense smoke without interference from obstacles or environmental conditions. Installing smoke detectors above suspended ceilings or beneath raised floors is generally not advisable because these locations can impede smoke from reaching the detectors in a timely manner.

In suspended ceilings, smoke may take longer to travel up and reach the detector due to the space and potential barriers, diminishing the device's effectiveness. Similarly, beneath raised floors, smoke may become trapped or fail to rise adequately to alert the detector. For this reason, smoke detectors must be placed in proper locations, typically mounted on walls or ceilings in the occupied spaces of a building where they can respond quickly to the presence of smoke, ensuring the safety of occupants and facilitating timely responses to fire events. Thus, the answer is that smoke detectors should not be installed in these areas for environmental air.