Cavity "Mini Air Cooling Fan" box toward the positive direction of the thin air, completely closed in the opposite direction thick sheet metal wrapped after leaving a narrow gap in a circle, this gap is to vent air from the base up, spread out the wind box filled cavity, it will accumulate to a certain extent than normal atmospheric pressure chamber in vitro, thus forming the wind. The rear end of the front end of a narrow cavity generous experience forced airflow inside the cavity toward the rear end of the broader movement, constantly squeezing each other's air last only go from tiny slit, after continuous operation for some time, this "Mini Air Cooling Fan"structure can gradually strengthen air pressure, resorted to air gap intake air flow in the direction of the wind out of the box once the chamber outlet flow rate, the effect of the formation of hair, it will cause the air box to follow the flow of air around stand up. On the one hand, "Mini Air Cooling Fan" will air on the back came from the supplement forward, to strengthen the central air effect.