9.32.3.8.(2)

Intent 1:

[Clause (a)] To limit the probability of excessive negative pressure, which could lead to:

• the spillage of combustion products from fuel-burning appliances that are susceptible to spillage, or
• moisture ingress from the ground.

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:

[Clause (b)] To limit the probability of an excessive volume of makeup air, which could lead to excessive positive pressure, which could lead to condensation within assemblies.

This is to limit the probability of:

• 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.