With the Air Sponge dehumidifier from Williams, you get maximum control of excess indoor moisture, every moment of every day. The unit automatically samples the room are once each hour to measure the humidity level. If required, the fan and compressor activate and continue to run until the humidity level in the air reaches the preset level. If cooling is required the Air Sponge simply shuts down until the air conditioner can adjust the temperature to the desire level. Once achieved, the Air Sponge resamples the room air to ensure a comfortable humidity level.