"Mini Air Cooling Fan" The main components are: AC motor. Its working principle is: energized coil in a magnetic field force rotates. Form of energy is transformed: the main electrical energy into mechanical energy, while the coil resistor, so there is an inevitable part of energy converted to heat. Due to poor design of air flow channel turbulent high-frequency noise will occur if the runner does not improve very difficult to have a qualitative improvement. Cooling fan speed sooner the better, the greater the larger the size of the fan air flow, cooling effect better. The larger the fan speed, the higher the noise, the greater the larger the size of the noise. After reducing the temperature difference between the temperature rises, the cooling effect is reduced.