Centrifugal In-Line Duct Fans are designed for Residential, Commercial and Light Industrial applications. Backward Curved Centrifugal Impeller gives superior performance in High Air Resistance applications. Most Clothes Dryers are designed with Dryer Vent of approx. 15 feet. Exceeding that length decreases airflow resulting in Increased Energy Costs and Excessive Dryer Wear and Tear.