Honeywell CO48PM 1062 CFM Indoor/Outdoor Evaporative Air Cooler Swamp cooler for both indoor and outdoor use when humidity level is 60Percent or less for maximum efficiency Best used when the air is hot with low humidity, such as Desert areas like the Southwestern United States Indoor use: for open environments with adequate cross ventilation up to 610 sq. Ft Outdoor use: weather resistant, UV protected, and has an air-throw up to 9.4 yards Non-compressor system Cools naturally, efficiently and inexpensively