Test method and failure criteria for the testing of combustible coverings and linings [of air duct systems] referred to in Sentences 3.6.5.4.(2) and (3), in buildings described in Sentence 1.3.3.2.(1) of Division A.

This also applies to:

• the fire safety characteristics of heating, ventilating and air-conditioning systems, as stated in Article 6.2.1.2., and
• buildings to which Part 9 applies [see Sentence 1.3.3.3.(1) of Division A for application of Part 9], with respect to:
  • mechanical ventilation systems other than self-contained systems serving single dwelling units, as stated in Sentence 3.6.5.4.(2),
  • the ventilation of storage garages for more than 5 motor vehicles in residential occupancies, as stated in Sentence 9.32.1.1.(3),
  • mechanical ventilation systems used for the ventilation of rooms and spaces in dwelling units during the non-heating season, where natural ventilation is not provided in accordance with Article 9.32.2.2., as stated in Clause 9.32.2.1.(1)(b),
  • heating 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 in which the rated heat input exceeds 120 kW, as stated in Sentence 9.33.6.1.(2).

To limit the probability that combustible coverings and linings of air duct systems will flame, glow, smoulder or smoke when exposed to fire conditions, which could lead to the coverings and linings contributing to the growth or spread of fire, which could lead to the spread of fire to other parts of the building by means of the air duct systems, which could lead to harm to persons.