Our ventilators are with fantastic fan with excellent performance and elegant shape for circular pipe. With the perfect match between new designed shell and backward centrifugal impeller, our ventilators have the best pneumatic and hydrodynamic performance as well as compact size and practical application, our ventilators are easy to be installed, lightweight, quiet, and able to provide strong power for air feeding, exhausting, returning and purifying. With extremely high pressure, our ventilators can be used for a pipe over several decameters long, able to control multiple areas by one ventilator and can be applied to buildings, indoor air exchanging and pipe pressurizing. Air intake and outlet are designed in compliance with standard pipe diameters and can be connected to a pipe directly at both ends. Our ventilators are wildly used in public places like hotel, hall, conference room, supermarket, station, airport, etc.