of 4-inch duct, and subtract 5 feet for every 90-degree turn and 2 1/2 feet for every 45-degree turn for dryer vent installation. For example, a dryer with a 90-degree elbow at the exhaust port ...

If the flap still won’t close, replace it. It only costs about $5 at home centers, and installing a new dryer vent will only ...