The Ontario Building Code | Air Filters and Equipment
6.2.4.14. Air Filters and Equipment
(1) Air filters for air duct systems shall conform to the requirements for Class 2 air filter units as described in ulc-S111, "Fire Tests For Air Filter Units".
(2) When electrostatic-type filters are used, they shall be installed so as to ensure that the electric circuit is automatically de-energized when filter access doors are opened or when the system circulating fan is not operating.
(3) When odour removal equipment of the adsorption type is used it shall be,
(a) installed to provide access so that adsorption material can be reactivated or renewed, and
(b) protected from dust accumulation by air filters installed on the inlet side.
6.2.5. Heating Appliances, General
In Plain Language
Air filters for residential duct systems must conform to the same Class 2 air filter unit fire-performance requirements referenced throughout the Code's HVAC provisions.
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.