Aprilaire 558 0.5 Gallon Humidifier

Aprilaire bypass humidifiers, like the Model 558, move air through the bypass principle, where air is forced from the warm air supply to the cold air return due to positive air pressure in the supply and negative air pressure in the return. The humidified air mixes with the return air from the home and is then distributed to each room. The Model 558 bypass humidifier, our smallest unit, measures just 12-7/8 wide by 12-3/4 high by 9-1/8 deep. It is designed for application in up to 3,000 sq. ft. tight homes. Along with all other models (except the Model 448), it is equipped with a drain to flush minerals from the system.