"Waterproof Cooling Fan" dual ball bearing cooling fan fan is to rely on the input of mechanical energy, improve gas pressure side to send a gas driven fluid machinery. Can be made of two types of right-handed and left-handed, face impeller rotates clockwise from the motor side, as the right cooling fan rotation, counterclockwise rotation, called L. "Waterproof Cooling Fan" works with turbine compressor basically the same, but because of the low gas flow rate, pressure changes little, generally do not need to consider changes in the specific volume of gas, that gas as an incompressible fluid handling. Newly installed cooling fan air flow will be too large, newly installed after the cooling fan began formal operation, or use of the process occurs too large or too small, can be used to eliminate one of the following methods: changing the cooling fan speed to regulate the flow. "Waterproof Cooling Fan" by adjusting the degree of opening and closing the door to regulate the flow. Changes in the pipe network regulate the flow resistance coefficient. Higher or lower exchange pressure regulated flow cooling fan.