Understanding the Three Sources of EC Fan Noise and Ways to Eliminate It

EC fans are an essential part of many industries, used in ventilation systems, air conditioning, and cooling systems. However, the noise generated by EC fans can often prove to be a significant problem. EC fan noise is caused by three sources: aerodynamic noise, mechanical noise, and electromagnetic noise. In this article, we will discuss these sources and explore ways to eliminate them.

The Three Sources of EC Fan Noise

Aerodynamic noise:

This type of noise is caused by the vibration of air molecules as they move through the EC fan. It is typically the most common source of EC fan noise.

Mechanical noise:

This type of noise is caused by the vibrations of the solid components of the EC fan, including the blades, motor, and housing.

Electromagnetic noise:

This type of noise is caused by the electrical components of the EC fan, including the motor and control circuitry.

Reasons for EC Fan Noise

Blade rotation:

The faster the EC fan rotates, the louder the noise.

Vortex noise:

When blades generate vortices, it produces noise.

Turbulent flow noise:

Occurs when the air passing through the EC fan creates turbulence, resulting in noise.

Resonance with the outer casing:

If the EC fan resonates with the casing, it produces noise.

External factors:

Other external factors, such as adjacent equipment, may also produce noise.

Eliminating EC Fan Noise

There are several ways to eliminate noise, both on the customer side and the manufacturer side.

Aerodynamic noise（customer side）

• Add sound insulation materials inside the device, such as glass wool, slag wool, foam plastic, and cotton wool.
• Adjust the device's material thickness to avoid resonance due to the EC fan's frequency.
• Reduce the EC fan's rotational speed to reduce noise.
• Change the size of the impeller to use a larger impeller and lower speed to reduce noise.

Mechanical noise (manufacturer side )

Ensure that there are no foreign objects in the rotor causing friction noise.

Confirm that the EC fan is running stably, and the dynamic balance is good, reducing any vibration noise by using balancing equipment.

Electromagnetic noise(manufacturer side)

• Use magnetic rings or tiles to ensure sufficient magnetism.
• Use skewed magnetization characteristics.
• Eliminate electromagnetic noise by using control boards that produce sine waves.

Contact PBM for EC fans today

If you have high requirements for product noise, we recommend using PBM's axial fan, centrifugal fan, and mixed flow fan to match your product needs. These three products fully consider noise reduction during the initial design stage.

PBM is a leading manufacturer and technology consulting company for EC brushless motors in China mainland. The company offers extensive ranges of EC motors, EC fans, and intelligent ventilation solutions designed to move air quietly and precisely. By understanding the sources of EC fan noise and implementing effective solutions, PBM is committed to providing customers with quiet and efficient EC fans for their needs. For more information about EC fans, kindly contact us today.