In disclosed embodiments the diameter of the outer portion of the cylinder shaped air diverter 206 is preferably the same diameter as the fan hub (e.g., 59 mm). Preferably, the distance from the bottom of the cylinder air diverter 205 to the fan hub 691 is about 2 mm. The bottom of the cylinder air diverter 206 is open for molding purposes and is not important to the design. The top of the cylinder air diverter 206 is a flat blocked surface.