The Honeywell 500 CFM indoor 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, place near open door or window, plug it in, and use. This unit is ideal for indoor use in open environments with adequate cross ventilation up to 300 square feet. Four fan speeds and oscillating louvers evenly distribute cool air through the honeycomb cooling media while the carbon dust filter cleanses the air. For those living in more humid climates, consider portable air conditioning units or window air conditioners.