This "220V Cooling Fan" Although the amount of wind and high static pressure are more FANa, but customers should use the best choice OPa; non only fan the maximum air flow and maximum static pressure as a selection basis. 3. The system impedance design quality also choose one of the key "220V Cooling Fan" of; R1 line impedance optimal system design, R2 line system impedance is higher, lower R3; to improve the system impedance should be designed from the system inlet and outlet the size of the adjustment, position adjustment in the emission system components, etc., then you can adjust it through the wind tunnel test and verify the best system impedance. Compare FANa motor torque can be learned and FANb FANa it with "220V Cooling Fan" fan, the more FANb good frame design features.