Ducting goes hand in hand with the extractor fans that are connected to the ducting system to enable the extraction or supply to materialize.  Extractor fans are key in the ducting extraction or supply systems as ducting is the driver or transporter of extracted substance.  Extractor fans are differently used, for kitchen extraction systems, spray booth systems, air supply systems, dust extraction systems, sawdust systems, toilet fans, ceiling fans and many more.  Fans are either wall mount fans, in-line fans, centrifugal fans etc.  Extractor fans are also heavily and mainly used in the air-conditioning systems with diffusers to either supply fresh air or extract hot air in the rooms.