Question: How much pressure does it take to open damper?
Answer: Any airflow will open the damper it is very minimal. The manufacture does not have a measurement on the airflow.
Question: Can this backdraft damper be used in gas stove pipes to keep air from coming?
Question: Can this damper be used as a takeoff from an HVAC duct that provides heating and air conditioning?
Question: Would this work in a dryer vent?
Answer: Yes, just be sure to install the damper between the fan and the exterior penetration of the building.
Question: Will this work vertical and horizontal?
4 Inch Duct Spring Loaded Backdraft Damper