A blower unit includes a housing, a shroud, a motor, a feed air impeller, a fan casing and a cooling air impeller. A motor shaft extends from both ends of the motor. The feed air impeller is attached to a front of the motor and the cooling air impeller is attached to a rear of the motor. The feed air impeller is contained in the fan casing. The shroud retains the motor and forms a guide chamber around the fan casing. The shroud is retained in the housing. Air is drawn through a front of the housing by the cooling air impeller. The air flows between the motor and the shroud and out of a bottom of the housing. Air is drawn by the feed air impeller and forced through the plurality of apertures in the fan casing and through a housing outlet by the feed air impeller.