What makes a Fan noisy


Sometimes we may hear unusual noises from a fan. These sounds are often an indication that a fan (no matter DC Fan or AC Fan) is not working properly. In general, there are a few different factors that may affect this noise level.


  1. Inadequate venting can increase the noise of a fan. This affects the impeller effectiveness and causes airflow (CFM) to drop. You can reduce this noise and improve your fan’s performance by increasing the vent area to 1.5 times of fan venturi.

  2. Airflow obstructions can also increase fan noise. If any obstacle is at the fan’s inlet or outlet and directly in the airstream direction, it will affect the airflow and is the same as inadequate venting. Try to move the fan farther away or remove the obstacle; this will reduce the issue.

  3. Vibration can cause the fan noise to increase, especially loose mounting screws. Fan are often mounted on a thin metal, laminate or wooden surface. The fan will vibrate against this surface. This surface can amplify the vibration to become soft noise, much like a large, poorly tuned speaker. This problem can often be solved by adding plastic or rubber grommets between the fan and mounting surface.

  4. Sometimes the fan noise comes from a bearing issue. If the fan has been run for long periods of time, the bearings may simply be worn out. You should arrange to replace the fan if this is your issue.