907.2.18.1 Smoke detectors.
BC § 907.2.18.1
Not fewer than one smoke detector listed for the intended purpose shall be installed in all of the following areas: 1. Mechanical equipment, electrical, transformer, telephone equipment, elevator machine or similar rooms.
2.Elevator lobbies.
3.The main supply, main return, and exhaust air plenum of each air-conditioning system serving more than one story and located in a serviceable area downstream from filters on supply ducts and in return/exhaust ducts downstream of the last duct inlet.
4.Each connection to a vertical duct or riser serving two or more floors from return air ducts or plenums of heating, ventilating and air-conditioning systems, except that in Group R occupancies, a listed smoke detector is allowed to be used in each return air riser carrying not more than 5,000 cfm (2.4 m 3 /s) and serving not more than 10 air inlet openings.
