The Honeywell 500 CFM indoor/outdoor evaporative air cooler offers an energy efficient cooling option when the air is hot with low humidity, such as desert areas like the southwestern United States (recommended humidity level is 60% or less for maximum efficiency). Honeywell evaporative air coolers do not require power hungry components like compressors. The low power consumption (only 235 watts) translates into significant savings on energy bills compared to using air conditioners. Just unpack, add water/ice, plug it in, and use. For outdoor use it is weather resistant, UV protected and has an air-throw up to 9.3 yards. For indoor use, place near an open door or window in an area up to 300 square feet with adequate cross ventilation. This model also includes an extra honeycomb filter. For those living in more humid climates, consider portable air conditioning units or window air conditioners for indoor use.