Acoustic Challenges in Electric Vehicles: A Comparative Study of HVAC Noise in EVs and ICE Vehicles

With the transition from ICE vehicles to EV’s, the dominant noise sources within the vehicle cabin have shifted from engine noise to auxiliary systems, especially HVAC systems. In conventional vehicles with internal combustion engines (ICE), engine noise tends to mask auxiliary noises. However, in electric vehicles (EVs), the lack of engine noise causes these auxiliary noises, such as those from the HVAC system, to become more prominent and potentially uncomfortable for occupants. The primary objective is to understand how the absence of engine noise in EVs influences the perceived HVAC noises. The research methodology involves static and on-road testing of both electric and ICE vehicle having common platform, conducted under similar testing conditions. The study aims to quantify and compare the acoustic characteristic differences of HVAC noise between ICEs and EVs, primarily focusing on cabin airflow noise, refrigerant flow noise, and AC compressor engagement/disengagement noise. Based on the findings, possible solutions were identified for areas where EV’s exhibit worse noise signatures compared to ICE vehicles, leading to improved acoustic comfort within the cabin. The findings can be beneficial for automotive manufacturers focusing on HVAC noise quality improvements in electric vehicles.