Central air conditioning is an important device for controlling the temperature in floating production storage offloading （FPSO） living quarters， mainly composed of chiller units and air handling units. By elaborating on the cooling characteristics of central air conditioning and the existing problems of air handling units， different types of fan failures were analyzed. By measuring vibration values， measuring environmental humidity， replacing belt materials， and changing belt models， the application effects were studied， providing a reference theoretical basis for reducing the frequency of fan failures in central air conditioning air handling units.