Design, construction and installation of heating, ventilating and air-conditioning systems that serve spaces that contain hazardous gases, dusts or liquids, in buildings described in Sentence 1.3.3.2.(1) of Division A.

This also applies to buildings or parts of buildings in which dust, fumes, gases, vapour or other impurities or contaminants have the potential to create a fire or explosion hazard, as stated in Article 3.3.1.20.

This also applies to buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9], with respect to:

• rooms or spaces intended for the storage, manufacture or use of hazardous or explosive material, as stated in Sentence 9.10.1.2.(4),
• mechanical ventilating systems other than self-contained systems serving single dwelling units, as stated in Sentence 9.32.1.2.(2),
• the ventilation of storage garages for more than 4 motor vehicles in residential occupancies, as stated in Sentence 9.32.1.1.(3),
• heating systems, including requirements for combustion air, and air-conditioning systems other than those serving individual dwelling units, as stated in Sentence 9.33.1.1.(2), and
• air duct distribution systems serving heating systems in which the rated heat input exceeds 120 kW, as stated in Sentence 9.33.6.1.(2).

To limit the probability that inappropriate design, construction or installation will lead to performance that is significantly below expectations, which could lead to the creation of ignition sources as a result of the use or operation of heating, ventilating or air-conditioning equipment, which could lead to the ignition of gases, dusts, vapours or residues, which could lead to fire or explosion, which could lead to damage to the building.