"24V DC Cooling Fan" to play the role of energy-saving control of the inverter and other equipment, the cooling fan selection, to choose the right size fan, should not choose unconventional size, fan speed is too high, that would lead to increased costs . What size regardless of the selected "24V DC Cooling Fan", we should first power consumption - saving; moderate speed and air flow - improve the efficiency of the fan; dual ball bearing - best to ensure the life of the fan; DC 24V voltage fan selection more appropriate, intelligent fan best choice with RD alarm function (this function inverter manufacturers in foreign countries has been more common to use) "24V DC Cooling Fan" use 220V voltage safer, because the current grid of undulating, use 380V voltage of the fan can easily burn-in, and electrical properties of the fan 220V AC voltage is relatively mature, the highest voltage reaches 260V are not easy to burn.