2. Centrifugal fan. When air is brought into the fan, it flows out in the radius direction by the centrifugal principle. This is mainly used for tunnel construction, mine work, factory production, ship driving, cooling and dust removal. It is widely used in industrial use. Many ventilation and ventilation facilities should use centrifugal fans, which are also used in hovercraft propulsion devices and grain drying. 　　

3. Mixed flow fan. Its air flow direction, centrifugal and axial flow type are different, between the two, this fan is easy to install, small size, low noise, high internal pressure, high power, can bring a large air volume, in hotels, guesthouses, office buildings, high-level civil facilities to make fresh air systems, mainly used for ventilation and exhaust. 　　

4. Cross-flow fan. The working principle of the fan is to direct the air flow into the vertical direction of the axis, and then flow out from the other side, its application scenario is narrow, mainly used for air conditioning internal units, of course, directly above the doors of hotels and shopping malls to increase the supply air volume, the production of air curtains can also be used this fan, can isolate dust and heat insulation.