Global Cancellation of Centrifugal Fan Noise

By Xiu-Wei Liu (劉修瑋)

The centrifugal fans are widely used in industrial equipment or consumer products for heat dissipation. However, noise generated by centrifugal fans is a crucial problem especially for some information technology (IT) products like laptops and medical equipment like continuous positive airway pressure (CPAP) respirators. This project presents development and performance evaluation of active noise control (ANC) system for reducing centrifugal fan noise. By placing multiple microphones and loudspeakers to the fan, the anti-noise signals are generated destructively interfere with the centrifugal fan noise at both the air entrance and exhaust sides. Real-time experimental results show that the proposed ANC system can achieve global cancellation of the centrifugal fan noise.