From "220V Cooling Fan" demand characteristics forecast for the use of a wide range of small and medium large DC fan, the product structure and manufacturing process is relatively simple, the cost is low, the user is the main pursuit of high efficiency, low noise, long life, and the price cheap. Another is the capital and technology intensive, "220V Cooling Fan" complex structure, long manufacturing cycle, complete and systematic also strong, and operated under high pressure, high temperature and high speed conditions, and some even run in bad conditions , users of the class DC fan have different requirements. Of the turbine drum "220V Cooling Fan" and compressor and large through DC fan, the user is the main pursuit of high quality, high reliability, smooth operation and long life cycle.