TM 9-4120-371-14
b. Adjust fresh air damper to desired setting. The unit can be operated in the VENTILATE mode with the
fresh air damper (door) closed, open or partially open.
NOTE
The fabric cover must be rolled up and secured if fresh air damper (door) is to be
opened. When using fresh air for ventilation a window, door, or vent should be opened.
If the room or enclosure is tightly closed, an overpressure will build up and decrease
the volume of fresh air drawn in.