DESC: The Air AC-1400E portable air conditioner is designed to condition an average-sized room up to 400 sq. ft. Patented Evaporative Booster Technology - During the cooling process, water is extracted from the air as it passes through the unit. Most of this water is used to cool the unit and make the AC-1400E run more efficiently. The New Air AC-1400E has a built-in water tank (not removable) with a drain outlet. When the tank fills, the compressor stops running. This indicates that the tank should be emptied.