This group includes Horizontal Roof Mounted Fans, Centrifugal Roof Mounted Fans, Vertical Discharge Centrifugal Fan, Roof Mounted Axial Extract Fan. Roof fans are manufactured in two different types as horizontal and vertical blow. It is also used in hood suction systems due to the fact that the fans have sparse blades and the possibility of the electric motor apart from the air flow. Roof Type Fans are used for light to medium density particle transfer.