Tamarack's Cape Damper consists of a fabric sleeve attached to an outer metal duct. The fabric sleeve will allow air to pass through in the desired direction of flow with a miniscule reduction in airflow. For reverse airflow the backdraft damper will reduce the airflow. The Cape Damper is quiet, with no metal clanging sounds, and can be installed in a horizontal or vertical orientation. It is available in two sizes, 4" and 6".
The Cape Damper will not contribute to increased static air pressure as much as butterfly and gravity backdraft dampers will. Understand that this backdraft damper is not going to offer as tight a reverse airflow seal as a spring-loaded butterfly damper, but it will not impede the forward airflow as much as other dampers will.
