Hello Rockford, the i-EcoDefrost function should be mentioned here. This controls the entire dehumidifier. To the question: The fan stops completely after reaching the target humidity. The fan is activated for 5 minutes per hour to circulate the air in the room. If the humidity in the room has risen above the target value again, the dehumidifier restarts. Otherwise, ventilation is repeated for 5 minutes in 1h. This function is unique on the market. Thank you and best regards Manuel Rupp