Abstract: A cooler curtain for maintaining an air barrier between the opening of a storage facility and the surrounding atmosphere. A plurality of closely spaced, resilient self-closing curtain elements are relatively movable between a closed position in which the elements of a pair thereof are closely adjacent and combinatively define an air barrier to impede air movement through a portion of the opening, and an open position in which the elements in the pair are spaced further apart to provide access therebetween to the storage unit through the opening. A drop-in removable insert frame structure is suspended over the horizontal, top opening of the storage facility to position the curtain elements over the front opening and top opening forming the air barrier. The plurality of self-closing curtain elements extend horizontally between the side rails of the frame over the top opening, and depend generally vertically from the front rail of the frame over the front opening.