Select this option if your humidifier is a scrubber type. This type is commonly used in Europe and consists of a fill valve, water tank, pump, spray bar, and optional drain valve. If you select the optional Drain Valve, you have additional options to Open valve if scrubber is inactive to drain the tank when not in use, and Open Valve on Network Input to drain the tank when commanded through a network input. You may optionally select Humidifier Status to indicate when the humidifier is operating.