This group includes Centrifugal Inline Duct Fan, Mixed Flow Inline Duct Fan,Wall Mounted Centrifugal Inline Duct Fan, Rectangular Inline Centrifugal Duct Fan (Backward Curved), Rectangular Inline Centrifugal Duct Fan (Forward Curved), Belt Driven Centrifugal Duct Fan (Forward Curved), Square Case Centrifugal Duct Fan, Centrifugal Kitchen Exhaust Duct Fan, Centrifugal Kitchen Exhaust Duct Fan (Forward Curved), Centrifugal Kitchen Exhaust Duct Fan (Backward Curved). Duct fans can also be in centrifugal and axial structure. Their characteristics are installed inside the ducts to ensure the circulation of the ambient air, the fresh air flow inside and the polluted air inside to be thrown out.