Patent ID: 6942459

Claim:
A centrifugal fan wheel comprising: a) a hollow hub having: i) a hollow portion; ii) a hollow hub axis connected to a top of the hollow hub at a center of the hollow portion protruding toward a bottom of the hollow hub; iii) a closed part located on the bottom of the hollow hub; iv) a curved guiding inlet part located on a side of the hollow hub; and v) a curved surface located between the closed part and the curved guiding inlet part and having a smooth fillet extending to the closed part; and b) a set of blades located on an exterior of the hollow hub and having: i) an up ring located on a top of the set of blades; ii) a down ring located on a bottom of the set of blades and having an inner part connected to the closed part of the hollow hub and a plurality of perforations located through a bottom thereof, each of the plurality of perforations is spaced apart an equal distance; iii) a plurality of blades located between the up ring and the down ring, each of the plurality of blades is spaced apart an equal distance; and iv) a plurality of wind holes located between the plurality of blades; wherein each of the plurality of wind holes communicating with an exterior of the bottom of the set of blades through one the plurality of perforations.