Sentence 9.32.3.11.(1)

Intent 1:

To limit the probability that ducts will leak, which could lead to failure to completely remove pollutants or water vapour from buildings, which could lead to:

• the discharge of pollutants into living space or into spaces that communicate with living spaces, or
• condensation, which could lead to the generation of pollutants from biological growth or from materials that become unstable on wetting.

This is to limit the probability of negative effects on the air quality of indoor spaces, which could lead to harm to persons.

Intent 2:

To expand the application of Section 9.33. to include ventilation ducts and their fittings installed in dwelling units.

Intent 3:

To exempt certain exhaust ducts from the requirement to be made of noncombustible material as stated in Article 9.33.6.2., on the basis that the ducts are unlikely to contain grease or other ignitable pollutants.

Intent 4:

To direct Code users to Sentence 9.32.3.11.(6) for requirements regarding ductwork for range hoods and range-top fans.