Unlike most humidifiers, the 9 Gallon Recirculating Humidifier from Lasko offers an evaporative filter for your humidification needs. That means that instead of producing mist, water droplets, steam or excessive condensation, this humidifier disperses invisible moisture, eliminating any threat of oversaturation in your room. Because it operates without oversaturating, the risk of molding is removed. You do not have to worry about the tap water that you fill this humidifier with; the evaporative feature will filter out any unwanted minerals, thus restricting any white dust to be dispersed into the air. Filling the humidifier is simple due to the dual handles on the removable water reservoir. The reservoir is capable of holding up to 4-1/2 gallons of water with a 9 gallon daily output. This 9 gallon humidifier can work in large rooms up to 3200 sq. ft. and is mobile on any surface because it sits on castors. You can operate this humidifier with its adjustable humidistat and three comfort control speeds. Thanks to its patented, cascading waterfall with a viewing window, you’ll even be able to see when it is in operation.