Based on practice and research in performance test of direct air-cooling system

some imperfect points stipulated in VGB guidlines have been expounded

and the tightness of vacuum during performance test of air-cooling system has to be ≤ 200 Pa/min being put forward.On the basis of different purposes of test and different situations of equipments

the temperature of wind entering into air-cooling condenser at different locations may be adopted

the correct coefficient of fan's power can be selected as 1 in calculation during test;and adding correction coefficient for frequency of the fan;the certified power consumption range under designed environment condition and designed frequency of said fan has to be ±3% of the disigned value specified in evaluation indices of power consumption for air-cooling fans;the average environmental wind speed at height 1 m above the upper edge of the air-cooling condenser has to be ≤ 5 m/s in effective time of every test condition was stipulated as the environmental wind speed.