"220V Cooling Fan" in the inlet and outlet parallel; their performance ranged from axial fans and centrifugal fans, air volume, air pressure is large; it out of the wind and into the wind with a tilt angle, if the two fans in parallel , the air flow can spread to the entire system. In order to make the most efficient fan, the optimum operating point at 1/3 of the axial fan after fan characteristic curve, ie air volume, wind down range. According to the actual situation, if "220V Cooling Fan" air flow enough, it may also be 1/3 of the foregoing, that a small amount of wind, high wind pressure range, to avoid the unstable region in the middle; the optimum operating point of the centrifugal fan before 1/3 of the fan characteristic curve, namely high pressure range; fan cooled card from the distance is greater than one times the minimum thickness of the fan; "220V Cooling Fan" fan outlet is on the front of the device should be avoided local personnel to operate; the cooling fan power equipment shall not exceed 10% of the overall power consumption.