Backdraft Damper Airflow Control Valve

This model is a round backdraft (or intake) damper designed to prevent cold air from flowing back into warm air ducts, e.g. a bathroom extractor fan. It allows airflow in one direction while blocking reverse airflow.The model has a cylindrical frame with an hinged flap valve. When air flows through the duct in the intended direction, the flaps open freely to allow air to pass. As soon as the airflow stops or reverses, the flaps swing shut to seal off the duct.Key features:Cylindrical frame with