Intent 1:
To limit the probability that:
- pollutants or water vapour will not be removed from
the building, or
- when an exhaust system is not in operation and conditions
of positive wind or stack effect pressure exist, airborne contaminants
(e.g. exhaust fumes from a parking garage) will enter the building.
This is to limit the probability of
negative effects on the air quality of indoor spaces, which could
lead to harm to persons.