The Ontario Building Code | Exhaust Ducts Serving More Than One Fire Compartment
188.8.131.52. Exhaust Ducts Serving More Than One Fire Compartment
(1) Where a vertical service space contains an exhaust duct that serves more than one fire compartment, the duct shall have a fan located at or near the exhaust outlet to ensure that the duct is under negative pressure.
(2) Individualfire compartments referred to in Sentence (1) shall not have fans that exhaust directly into the duct in the vertical service space.