If your dryer vent is longer than 35 feet, we recommend that a booster fan is installed to help your system run more efficiently. The airflow through your dryer vent cannot be maintained at the speed necessary to move lint for more than 35 feet. A professional booster fan installation provides proper airflow throughout the entire system. Proper airflow is essential for reducing lint build up and keeping your dryer working efficiently. An efficient dryer saves you money by reducing drying time.