NRD61 – back draft damper

Back draft dampers also named non return dampers type ‘NRD61’, are designed for use intake and discharge opening in commercial and residential air conditioning systems. When the ventilation system is on, the blades of the non-return damper are held in the open position by the airflow. If the system is switched off, the damper blades close automatically, thus preventing reverse airflow and giving protection against the ingress of untempered air, rain and birds into the air conditioning system.

Design