Smoke Dectors

[Randazzo]

Imagine their is a sofit hallway containing duct work for a living room supply grill. Can you mount a smoke dector within 3' of this grill in the hallway. Note.. the sofit ceiling is 8" dropped from the concrete ceiling and the supply grill is facing into the living room.

Reason for this question is their is no allowable means for mounting this smoke dector in the hallway due to bathroom and return air AC closet. If I was to maintain the 3' Rule including the living room supply I would not be able to install the smoke anywhere.

 

[bphgravity]

Re: Smoke Dectors

For these situations, I feel it is preferable to install the smoke alarms in the least problematic location when all spacing cannot be maintained. In this case, I don't see why you must maintain spacing from the return register. The NFPA 72 11.8.3.5 indicate the spacing from the supply register only needs the proper separation.

That being said, if the smoke alarm is within 36" of the supply register but not in the direct air flow, it will probably still be effective.