In-cabin energy recovery ventilation for enhanced air quality and reduced air-conditioning energy consumption

Excessive carbon dioxide in vehicle cabins can impair driver judgment and compromise safety. Introducing fresh air into the cabin mitigates this problem but increases the cooling load and energy consumption of the air-conditioning system. To address this issue, this study proposes the use of an in-cabin energy recovery ventilation system that exchanges heat between the expelled cabin air and the incoming fresh air, thereby reducing the cooling load and energy consumption. The system is equipped with a high-efficiency filter that removes suspended particulates from the incoming fresh air, further improving the indoor air quality of the cabin. The performance of the ventilation system was evaluated using computational fluid dynamics simulations. With the system running at a low speed and five occupants within the cabin, the carbon dioxide concentration reduced from approximately 7600 to 3000 ppm within 30 min. Additionally, the number of suspended particles decreased by approximately half to 630 particles/cm³. At high speeds, the carbon dioxide concentration decreased to 2400 ppm after 30 min, and the suspended particle concentration decreased to approximately 530 particles/cm³. The corresponding net energy savings were estimated to be 79.6 and 110.3 W, respectively. The results demonstrate that the proposed system effectively improves the in-cabin air quality while simultaneously enhancing energy efficiency.