Centrifugal fan selection needs to provide air volume and pressure, fan flow units are m3/h, m3/min, m3/s, pressure units are pa, kpa, the greater the fan pressure the smaller the air volume, this can be seen from the fan selection programme curve, the same series of fans can meet many different flow pressure requirements, but the power required for each operating point is not exactly the same. The greater the flow rate, the lower the efficiency for the same fan. The higher the pressure, the more the same fan may stall, so the corresponding operating point should be selected within the curve.

      Centrifugal fan selection two to take into account the use of working conditions, according to the characteristics of different working conditions design and selection of fan materials. Chemical plants generally contain corrosive gases in the gas, need to consider the fan flow channel corrosion resistance. Cement plant to take into account the wear life of the fan, the dust content of high and low also determine the choice of impeller; therefore need to understand clearly the use of the fan environment, whether the dust and corrosive gases and so on.

      Centrifugal fan selection should also consider, for temperature and altitude, working temperature and altitude will affect the density of the gas, altitude will also be associated with air pressure, the pressure of the fan has an impact, usually the default is room temperature and plain, clear parameters requires can guarantee the correct selection of fan models.