Abstract: The fan has a volute inlet. Designing the shape of inlet to improve the heat dissipation of the fan. The fan has a volute inlet having a reference point on the housing with respect to an outlet. The blades are partially covered by the inlet from the reference point wherein an area of the blades covered by the inlet is from a maximum to a minimum gradually in a closed loop. As a result, the set up current of air can reach a maximum prior to output from the outlet, thereby increasing the heat dissipation capability of the fan.