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Pollution Flows in Underground Garage
Animation Series 4:
Pollution Flows in Underground Garage
Normal Flows with Exhaust Fan
Mouse over the animated picture above to see messages which are referenced in more detail below.
Pressure relationships between rooms is designated at the bottom of each room (with a plus for positive and minus for negative pressure).
- [GARAGE]: Exhaust fans in the garage are fully operational during significant use periods to insure that all garage contaminants are fully exhausted to the outside.
Exhaust fans may be in partial use during slack periods. Sometimes carbon monoxide sensors are used to control fan operations. In any case, the garage should be maintained
UNDER NEGATIVE PRESSURE relative to the building at all times.
- [VESTIBULE]: The vestibule is acting as a buffer between the garage and the occupied spaces in the building. It may be subject to slight depressurization because of a stack effect up the elevator shaft and stairwell which draws some air, and because of the exhaust fans in the garage. However, some ventilation air is supplied through a supply air duct to neutralize this effect. Some air flows up the elevator and stairwell, and some flows from the vestibule into the garage. But garage pollutants do not enter the vestibule.