duct booster fan
A duct booster fan is a fan that is installed between sections of round metal or flexible duct sections in order to improve air circulation through the duct. A duct booster fan is useful where at least one room in a home or other building suffers from poor delivery of heated or cooled air, or there's a need to exhaust an area where moisture or fumes build up. The fan can be wired to turn on with a furnace or central air conditioner blower fan or may contain a pressure sensor that senses positive pressure from the central blower.
Many different makes and models of duct fan are available to suit different duct sizes, types, and applications. They are generally easy to install and may come with extras such as speed control. To get the most efficient performance from a duct booster fan it should be located near the outlet end of a duct.