Improve airflow in long dryer vent systems with this 4 in. dryer booster fan delivering 170 CFM at 0.2 in. static pressure (HVI rated). Designed for extended or complex dryer exhaust runs, this inline duct fan is ideal for duct systems exceeding the standard 25 ft. vent length or installations with multiple bends. By increasing airflow through the duct, it helps reduce drying time, lower energy consumption, and minimize lint buildup that can create a fire hazard in dryer vent systems. An automatic pressure switch turns the fan on when the dryer runs and off when it stops. For proper installation, mount the fan at least 15 ft. from the dryer in the path of the existing duct. When installed correctly, it supports vent runs up to 150 ft. while maintaining effective exhaust performance. With a 4 in. duct connection and durable inline construction, this dryer booster fan provides reliable airflow for residential, commercial, and light industrial electric dryer applications.