Round Backdraft Dampers - Non return dampers

Backdraft damper - what are they made of? 

Backdraft dampers also refer to as non return dampers have a split flap closure and allow the airflow to pass in one direction only. The aluminium closure flaps are pressed against a foam seal when closed to reduce the operating noise in the ductwork.

The split flap closure is held closed with a spring gear, which makes it also possible to use the backdraft damper in vertical installations.

Backdraft damper types in Alnor offer

• backdraft dampers are available in versions with a rubber seal (DAOSL) and without (DAOS);
• backdraft dampers with additional reinforcement rod (DAOSL-B and DAOS-B);
• backdraft damper that slips inside the ducting (DAOSL-IN).