Abstract: A self-contained induction air supply unit is provided for an exhaust hood having an exhaust fan drawing of freeze laden air through an angled filter. The supply unit includes a supply chamber with a bottom stream forming slot having a curved bottom wall for turning air through the slot and into the exhaust hood. An air deflector includes an adjustable support coupled to the curved bottom wall to vary the angular orientation of the stream to permit changing the angle of the induction air stream for proper engagement with the filter and simultaneously change the curved bottom wall. The deflector in one form includes a single plate having a curved portion abutting the underside of the curved bottom wall and an outer planar portion. In another structure the curved bottom slot wall is flexibly mounted. A deflector plate is pivotally mounted beneath the outer end of flexibly mounted wall and projects outwardly thereof.