The Helios Fans DRVM 200 is a circular backdraft damper designed to block cold air from entering the ductwork when the fan is not in operation. It features a spring-return motor mounted outside the airstream, which automatically closes the damper when the fan is turned off. Electrical control is synchronized with the fan using a 0.9‑meter cable.
Constructed from robust cylindrical sheet steel, the housing includes flanges on both ends for easy mounting. The DRVM 200 is directly attachable to the fan base plate or flange and follows the hole pattern specified in DIN 24155. This damper is not suitable for use in explosive (Ex) environments.