Patent ID: 7048499

Claim:
An axially extending inline centrifugal fan for circulating air within an ambient environment, the fan comprising: (A) a conduit having an intake end and an outlet end; (B) an inlet cone disposed at the intake end for receiving air from the ambient environment; (C) an impeller disposed downstream of the inlet cone and including: (i) a centrally disposed wheel-back configured for rotation by an electric motor; (ii) a plurality of fan blades extending radially outwardly from the wheel-back operable to force air in the direction from the intake end to the outlet end; and (iii) a wheel cone fixedly attached to, and circumscribing the wheel blades; and (D) a drive chamber disposed downstream of the impeller including a plurality of radially extending straightening vanes operable to receive the forced air from the impeller and direct the air substantially axially downstream to the outlet end; wherein the inlet cone has a discharge diameter of substantially 0.75 times a diameter defined by radial outermost edges of opposing fan blades; wherein the inlet cone has an axial length substantially between 0.17 and 0.21 times the diameter defined by the radial outermost edges of opposing fan blades.