Parallel Fan-powered VAV box. The operational unit is the flow sensor and motor fan assembly, and it is equipped with various necessary controllers depending on the kind of application. The fundamental model of this type of terminal contains an initial flow damper. Open coils of electric heating and hot water are also employed to account for any fluctuations in the area’s load.

The outdoor areas of buildings are where the variable volume air terminal with parallel flow fan is most frequently employed. Additionally, it enables the central ventilation system to shut off when the room is unoccupied for a predetermined amount of time. In this instance, the fans and heating coils of the terminals individually supply the requisite heat to keep the area at the minimum required temperature during the central system shutdown times.