A duct booster fan is an auxiliary fan installed inside a duct run to help push air to a room that is too far from the main air handler. These fans are a lifesaver for large homes where one bedroom always seems to stay warmer than the rest during the summer. By increasing the airflow velocity, the booster fan ensures that the conditioned air from your Air Handlers actually reaches its destination. You can find various sizes of booster fans in our Fans collection, including models that turn on automatically when they sense airflow. While they are a great "fix-it" solution, they should not be used to compensate for poorly designed or undersized Ducted systems. Proper installation involves placing the fan mid-way through the run for the best performance boost. They are an inexpensive way to improve the comfort of a specific room without replacing your entire ACIq unit. These fans are a popular DIY upgrade for improving overall air distribution.