There are two reasons for the negative pressure of the new fan noise: one is the external cause; the other is the cause of the fan itself. The following is a list of 6 common noise problems. Problem 1: The negative pressure fan is too tightly contacted with the window frame during installation, causing the window frame to resonate when the negative pressure fresh fan operates. Solution: The amount of packing between the window frame and the negative pressure fresh air blower should be appropriately reduced, and the softer material should be used for packing. The bottom of the installation should be stably fixed to the bottom and the installation should be stable and reliable. Question 2: The negative pressure fresh air fan is installed badly, and the negative pressure fresh air fan installation should be suspended. The spring of the foot bolt cannot be pressed to death. Solution: Ask the maintenance personnel to adjust the installation status of the negative pressure fresh air fan so that it is in a suspended state.

 Question 3: The negative vibration cushion or fixing screw of the negative pressure new fan frame is over tightened tightly, and if vibration is lost, vibration noise will be generated when working. Solution: Adjust the tightness of the screws on the negative vibration cushion of the new-pressure fan base, and make the plane surface smooth. Question 4: When the power supply voltage is too low, abnormal noise and vibration may occur when the negative pressure fresh fan starts or operates. Solution: Control the power supply voltage within the rated voltage range. A voltage regulator or power regulator can usually be used to stabilize the voltage. Question 5: The negative pressure fan blows against the blower shell (hood). Solution: adjust the fan six reasons: negative pressure fan motor fan bearing bad, the axial fan base screw loose, the fan blade is not fixed on the shaft, the fan blade and the hood body clearance is too small.

 Solution: Replace the bearing of the negative pressure fresh air motor and tighten the screws on the base and shaft of the axial fan. According to the production technology requirements, the distance between the top of the blade and the cover should be adjusted, which is generally less than the percentage of the length of the blade. Question 6: The base screws of the negative pressure fresh air fan are loose, the impeller assembly is bad, the rotation speed is too fast, and the fixing screws on the shaft are loose. Solution: Install the screws on the fan base and shaft of the negative pressure new fan. Reassemble and adjust the impeller clearance according to the technical requirements.