The Ontario Building Code | Outdoor Intake and Exhaust Openings
220.127.116.11. outdoorref ="http://thehandyforce.com/doors/" title ="Toronto Door installer">door Intake and Exhaust openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings
(2) Intake openings="http://thehandyforce.com/windows/" title ="Window installer in Toronto">openings shall be located so as to avoid contamination of the ventilation air from other local sources such as automobile exhausts and exhaust from adjacent buildings.
(3) The distance from the bottom of an air intake opening to finished ground level or to any nearer and lower permanent horizontal surface shall be not less than 450 mm or the depth of expected snow accumulation, whichever is greater.
(4) The distance separating air intakes from buildingenvelope penetrations that are potential sources of contaminants, such as gas vents or oil fill pipes, shall be not less than 900 mm.
(5) Air intakes shall be clearly labelled as such for identification from locations outside the dwelling unit.
(6) The distance from the bottom of an exhaust outlet to finished ground level or to any nearer and lower permanent horizontal surface shall be not less than 100 mm.
(7) Where air intake and exhaust openings are in exposed locations, provision shall be made to protect them from the entry of precipitation by the use of louvres, weather cowls or other suitable protection.
(8) Air intake openings shall incorporate screens or grilles to protect against the entry of animals and insects.
(9) Except for exhaust outlets serving heat recovery ventilators, exhaust outlets shall incorporate backdraft dampers.
(10) Except for clothes dryers, exhaust outlets shall be fitted with screens of mesh not larger than 15 mm, except where climatic conditions may require larger openings.
(11) Where a screen or grille required by Sentences (8) and (10) has a screen mesh less than 6 mm, the screen or grille shall be removable for cleaning.
(12) The gross area of the screens or grilles installed in intake and exhaust openings shall be three times that of the duct served.
(13) Screens and grilles shall be of corrosion-resistant material.
(14) The net free area of an air intake or exhaust outlet shall be equal to or greater than the cross-sectional area of the duct served.