Various types of garage ventilation systems are known in the prior art.  However, what is needed is a garage ventilation system including a housing body having a pair of side walls and rear and front mounting plates with louvered vents on the front mounting plates.  Support frames vertically disposed on the rear mounting plate have a channel longitudinally disposed therein and a stop body disposed within an outer end thereof.  A mount bracket engages each of the channels.  Legs disposed on each side of a central pivot member engage the respective channel with termination at the stop body.  The mount brackets extend outwardly and away from the rear mounting plate.  A fan casing, having a fan disposed therein, is rotatingly mounted to the mount brackets allowing rotation of the fan into an exhaust position and an alternate intake position to direct airflow away from or alternately into a garage.  A heater contained within the housing body generates heated airflow directed by the fan.