A cooling fan includes a housing and a motor. The housing includes a support portion, a cover portion and a lateral wall portion. The lateral wall portion is disposed between the cover portion and the support portion, and the lateral wall portion, support portion and the cover portion define a compartment, with the lateral wall portion having at least one lateral air inlet and at least one lateral air outlet penetrating through the lateral wall portion and communicating with the compartment. The motor is mounted inside the compartment of the housing and contains a stator and a impeller, with the impeller rotatably mounting to the stator. The motor further contains a hub with a top and a plurality of blades, with the top facing the cover portion, with the top and the cover portion delimiting a lateral flow path in the compartment, and with each blade being contained in the lateral flow path.