The best whole-house humidifier is the Essick Air MA1201, according to Consumer Search. This model is available from Amazon.com, as of 2015, and has received a rating of 3.9 stars out of 5 stars.
The Essick Air MA1201 has a 3.9-gallon tank and can produce as much as 12 gallons of moisture each day, which is enough to humidify up to 2,500 square feet. It features a digital display with a humidistat, and the humidity can be adjusted in increments of 5 percent. This humidifier has a double tank, a four-speed fan and a mildew-resistant filter. It also sits on swivel casters, which allow a person to move it easily from room to room.