These portable, self-contained units are about $320 and have an evaporative capacity of about twelve gallons per day. The AM 350/360 is able to humidify a home of up to 4,500 square feet. The Manual Humidifier Control, humidistat, is installed either in the cold air return duct or on an interior wall of the home. Automatic digital control would not work with the 350/360 Model. The automatic digital control must be mounted on the return duct at least 6 inches upstream from the unit. It is important to monitor changes in outdoor temperature and reduce the setting accordingly to avoid condensation. This control includes a Change Water Panel indicator and, for best performance, replacing the water panel evaporator in your AM 350/360 humidifier is recommended once or twice annually. The only difference between the two models is that the AM 350 can be hung from the floor joists in a basement where ductwork would connect to a floor vent in a central location in the home for distribution of the humidified air. This model can be placed in a basement between the floor joists allowing it to be mounted in a central location for more efficient home humidification. Ductwork would connect to a floor vent in a central location in the home for distribution of the humidified air. The 350 comes equipped with mounting brackets as well. The Model 360 can be placed in the central location of the home in a closet. The 360 is installed through the wall and is completely independent of the heating system. Like other Aprilaire humidifiers, this model comes with a five year warranty and the new Aprilaire 350/360 Humidifier Annual Maintenance Kit can be purchased separately as well.