The BAER Belt Drive Sidewall Propeller Fan is designed for expanded performance and improved efficiency in wall-mounted clean air applications. It features cast aluminum airfoil blades and hubs, an AC induction motor, and an automatic belt-tensioning system that minimizes regular maintenance of the fan belt. The automatic belt-tensioner will adjust tension as the belt wears, doubling the life of the belt while maximizing the life of the fan and motor.