Abstract: A refrigeration unit composed of a drop-in package to be accommodated within an aperture in the top of a cabinet, and comprising a plug insertable neatly into the aperture and mounting refrigeration components on top and an evaporator together with an air impeller in an underside compartment, abutment means on the plug to limit intrusion of the plug to a position substantially flush with the ceiling of the cabinet, and air ducts directing air flow from the air impeller in a path adjacent the ceiling due to a sweeping curvature of a wall of each air duct which influences the path of air flow in compliance with the "Coanda" effect.