The FreshMist unit mounts outside your ducts. It routes some of the airflow through a chamber where a rotating evaporative drum humidifies the air. The humidified air is then routed back into the duct. The included humidistat control allows you to set your desired humidity level. The system will automatically cycle on and off to maintain that level.
Water level is also automatically refilled and maintained.
Power supply can be plugged into an X10 Appliance Module for home automation integration if desired. The external duct design provides mounting flexibility and provides easy access for cleaning. Evaporative design ensures that only pure water vapor enters the air.