For "Axial Fan" should be noted that, although reflecting fan total energy concept with full pressure, but the pressure of the whole kinetic energy tends to account for a large proportion, but really overcome the pipeline resistance is part of the total pressure of the kinetic energy. Official channel resistance is large, with a total pressure to determine the operating point is difficult to meet the requirements of the system. Thus the fan operating point and sometimes static pressure flow curve Pst-QV and characteristic curve of the intersection of M, see Figure 5-1 p-QV fan performance curve and characteristic curve intersection N is the total points of the fan.