Abstract: An energy-saving cover for evaporative coolers. An oversized top portion provides a sufficient overhang about all four sides of the cooler for shading purposes. An insulative side panel is associated with each of the sides of the cooler and the panels are positioned a predetermined distance away to allow sufficient air flow to improve the cooling efficiency of the cooler during the cooling season. During the heating season the side panels may be repositioned onto close flush against the sides of the cooler so as to seal the vent portions thereof and prevent the escape of warm air from the dwelling through the duct system. Additionally an interior duct cover can be used to seal the cooling vent to prevent the escape of warm air from the room having the cooling vent thereby saving energy and increasing heating efficiency in the heating season.