9.33.6.7.(7)

Intent 1:

To limit the probability of the accumulation of water in ducts, which could lead to:

• excessive relative humidity, or
• the accelerated deterioration of ducts.

This is to limit the probability of the generation of pollutants from biological growth or from materials that become unstable on wetting, which could lead to:

• negative effects on the air quality of indoor spaces, or
• the inadequate thermal comfort of persons.

This is to limit the probability of harm to persons.

Intent 2:

To limit the probability of the entry of sewer gases into duct systems, which could, on system operation, lead to the distribution of sewer gases throughout living spaces, which could lead negative effects on the air quality of indoor spaces, which could lead to harm to persons.