We have a large distribution warehouse that was recently updated with roof top supply fans. The fans are unducted and provide fresh air into the building. The AHJ says these fans must have smoke detectors on them.. NFPA mentions smoke detectors in ducted systems, but does not say what to do on unducted fans.
These fans supply air at 20,000 cfm. Do they need smoke detectors? Has anyone installed a smoke detector on fams like these?