What are outdoor air (OA) dampers and how are they used?
A properly designed, installed, operated, and maintained OA damper will preclude the entry of water (rain, snow) into the AH system and will stop the flow of air into the system when it is closed. When open, it allows the AH equipment to supply a known amount of fresh outdoor air (OA) to the building to dilute air contaminants that are generated by the building, its furnishings, and its occupants. Damper-controlled OA also provides for space pressurization (to help prevent infiltration of air at the building exterior wall or “envelope”) and makeup air for building exhaust fans (e.g., kitchen, bathroom, mechanical room, hoods).
