Patent ID: 7874268

Claim:
A method for adjusting airflow in a rodent containment cage to a set level, which comprises: ventilating the rodent containment cage with a blower assembly connected to the rodent containment cage with an air supply conduit, air exhaust conduit or both an air supply conduit and air exhaust conduit; sensing air pressure with an air pressure sensor disposed in the air supply conduit or air exhaust conduit connected to the animal cage wherein the sensor sends an air pressure signal directly to a controller; comparing the sensed air pressure to a set level of air pressure by the controller; and increasing or decreasing the speed of one or more fans in the blower assembly until the air pressure reaches the set level, wherein the controller slows the response rate for increasing or decreasing the speed of the one or more fans when the air pressure signal sent by the sensor to the controller is near the set level.