An electronic device. The electronic device comprises a heat source, a housing having an inlet and an outlet, a fan disposed in the housing and selectively rotating at a first speed and a second speed higher than the first speed to generate air flow in the housing to cool the heat source, and a plurality of louvers disposed on the housing, having adjustable angles and selectively positioned at a first angle and a second angle. When the louvers are positioned at the first angle, the fan rotates at the first speed, and when the louvers are at the second angle, the fan rotates at the second speed.