The Ontario Building Code | Smoke Detectors in Recirculating Air Handling Systems
9.10.18.5. Smoke detectors in Recirculating Air Handling Systems
(1) Except for a recirculating air system serving not more than one dwelling unit, where a fire alarm system is required to be installed, every recirculating air handling system shall be designed to prevent the circulation of smoke upon a signal from a duct-type smoke detectorwhere such system supplies more than one suite on the same floor or serves more than 1 storey.
In Plain Language
Smoke detectors in recirculating air handling systems must meet the requirements set out in this article, since a forced-air system can otherwise spread smoke throughout a building before anyone notices.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.