HVAC Ducts

By Kuan-Chun Chen、Chun-Ning Chiou (陳冠勳、邱群甯)

This project implements active noise control (ANC) system in an HVAC (heating, ventilating, and air conditioning) duct to reduce the noise in public buildings. The HVAC system delivers fresh air to every room in a building; however, it also produces low frequency noise. The traditional method uses passive noise control which uses relatively large and costly materials, and is ineffective at low frequencies. ANC technique is implemented to reduce noise in a duct. Experimental results verify the effectiveness of the ANC system for HVAC ducts. The bandlimited white noise (100-1000 Hz) can be reduced 24-25 dBA at the end of the duct by sound pressure meter. People in lab can strongly feel the difference before and after the ANC system turning on.