Indoor covers for air conditioners of any size are available at The Cover Store. Prices range from about $10 to about $15, depending on size, as of March 2015. Exterior covers for air conditioners of various sizes are available at Amazon.com and Wal-Mart.
Indoor air conditioner covers improve energy efficiency by providing insulation against drafts. Outdoor air conditioner covers seal out dust, weather and leaves. Indoor and outdoor air conditioner covers wrap one side of the unit and are held in place by adjustable elastic straps.
The Cover Store recommends measuring the height, width and length of your air conditioner, and ordering a cover that is slightly larger than the dimensions of the unit.