An air damper assembly for regulating an air flow includes a frame, a plurality of elongated damper blade rotatably mounted to the frame, and a drive mechanism for actuating the damper blades between open and closed positions. The drive mechanism includes a gear fixedly secured to a distal end of each of the damper blades and an elongated rack slidably coupled to the frame. The rack meshingly engages the gears such that linear movement of the rack in a first linear direction results in rotational movement of the damper blades in a first rotational direction and linear movement of the rack in a second linear direction opposite the first linear direction results in rotational movement of the damper blades in a second, rotational direction opposite the first rotational direction.
