Products

NRDR – backdraft damper for round ducts

Backdraft dampers also named non return dampers type ‘NRDR’, are designed for use intake and discharge opening in commercial and residential round ducting 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.

Features

For automatic shutoff of the air ducts and prevention of back drafting when the fan is off. Suitable for installation in various premises.
Compatible with ∅ 100 up to 315 mm round air ducts.

Design

Galvanized steel case.
Two spring loaded blades made of aluminium.
Blades are opened by air pressure and are closed with a spring.

Mounting

Fixing to round ducts with clamps.
Provide vertical position of blade axis.
Install the backdraft damper into the ventilation system with respect to the air flow direction.