Self-acting back draught damper FIDm

FIDm is a self-acting back draught damper designed to prevent the spread of combustion gases via the intake air system in ventilation systems. FIDm is equipped with an actuator and is suitable for systems where you adjust the ventilation as required.

Quick facts

  • Sizes from Ø 100 to 250 mm
  • With actuator
  • Available in MagiCAD


The back draught damper should be used in combination with a fan in use solution, smoke venting via exhaust air or the like and to maintain its function requires the intake air fan to be operational during the fire. The fire protection functions work for all design fire scenarios that can be expected to occur with traditionally used fire development rates. Planning and fire protection analysis are to be made by fire experts.


FIDm has a simple pull-out insert with a membrane that closes very quickly with overpressure in the room. The design of FIDm means that the back draught damper has a low build height, but also that the insert is easy to remove. Removing the insert also allows access for inspection and cleaning of the duct in both directions.