One of the most common ways to talk about a "duct booster fan" is to call it "a booster fan." "Main ductwork can accommodate these fans, but they are more commonly found in small ducts serving a room. Adding this to your ductwork is meant to help the airflow to the rooms in your home that aren't near your heating and cooling system. It works with your heating, ventilation, and air conditioning (HVAC) systems.