Air Pressure

Published March 2002

Air pressure can be either positive or negative in reference to a designated area. In animal facilities, an animal room may have air pressure lower than the outside hall, causing the air pressure in the room to be declared "negative" in relation to that of the hall. Air would flow in from the hall to the room. An animal room with "positive" air pressure in relation to the hall would have air moving from the room to the hall. These pressure differentials are set so as to minimize contamination between areas.