Abstract: An air exhaust system comprises a chamber. The chamber has side walls, a ceiling, an attic and a roof. The ceiling and roof have air flow apertures. Provided next is a duct with upper and lower ends. A turbine fan is provided. The fan is operatively coupled to the upper end of the duct and rotatable about a vertical axis. The fan is further adapted to be self rotated as the air moves from a location in the chamber to a cooler location above the fan. Last provided is a damper. The damper is located above the lower end of the duct. The damper is moveable between closed and open orientations. The closed orientation precludes the flow of air through the duct. The open orientation allows for the flow of air through the duct.