Fan wind speed should not be too large to open, so that the human body has a process of adaptation. Indoor wind speed is best controlled at 0.2-0.5 m/s, especially in well ventilated room and in draughty place, fans of the wind speed but can not be too large. "Waterproof 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.