T & M Air Duct Cleaning carries Aprilaire Model 1820 and larger dehumidifiers. They are designed to dehumidify the air coming into the unit by passing the incoming air over an evaporator coil to drop the air temperature below the dew point of the air. Moisture is removed from the air and drained out of the unit to a common floor or waste drain. The air is then reheated in the condenser coils and exits the unit. We can take care of the installation and maintenance and service of your dehumidifier. This model comes with a 5-year warranty.