(1)
Supply, return and exhaust air openings located less than 2 m above the floor in rooms or spaces in buildings shall be protected by grilles having openings of a size that will not allow the passage of a 15 mm diam sphere.
(2)
Outdoor air intakes shall be located so that
(a)
the quality of the air entering the building complies with Sentences 6.2.1.2.(2) and (3), and
(b)
they are separated a minimum distance from sources of contaminants in accordance with Table 6.3.2.9.
(3)
Outdoor air intakes shall be installed not less than 0.3 m above roofs, landscape grades or other surfaces, taking into account anticipated snow accumulation levels.
(4)
Exterior openings for outdoor air intakes and exhaust outlets shall be shielded from the entry of snow and rain and shall be fitted with corrosion-resistant screens of mesh having openings not larger than 15 mm, except where experience has shown that climatic conditions require larger openings to prevent the screen openings from icing over.
(5)
Screens required in Sentence (4) shall be accessible for maintenance.
(6)
Combustible grilles, diffusers and other devices covering supply, return, intake and exhaust openings shall comply with Article 3.6.5.7.
Table 6.3.2.9. Minimum Distances of Air Intakes from Sources of Contaminants
Forming Part of Sentence 6.3.2.9.(2)
