"Axial Fan" fan total efficiency is the efficiency of short, refers to the percentage of fan output power to input power ratio. Fan reflect the extent of energy transfer process of the axis of the effective use of power, represented by η. Fan establish import and export of energy relations, with gas potential energy g (Z2-Z1) can be ignored, to get the energy per unit volume of gas obtained expression. That fan blower outlet is equal to the total pressure p total pressure 2p and 1p import total pressure difference. Under applicable to import and export the fan is not directly through the atmosphere (ie, configured with suction pipe and duct pressure), the total pressure is calculated fan performance testing. Importers joint experimental device called the system fan, one fan performance test different experimental setup used three.