The Impact of Bus Heating Ventilation and Air Conditioning Systems on Real-World Energy Consumption and Co2 Emissions

Abstract

The efforts to reduce CO 2 emissions from road transport have focused mainly on passenger cars, but the focus shifts to heavy-duty vehicles, which despite their low fleet share, contribute significantly to the sector's greenhouse gas emissions. The current study focused on a bus and investigated the effect of environmental conditions and passenger occupancy on auxiliary usage and CO 2 emissions. It utilised measurements conducted over the Zincirlikuyu – Avcilar route in Istanbul, Turkey, to develop vehicle simulation models. The vehicle was simulated under different environmental conditions and passenger occupancy, and it was found that the auxiliary use could differ between -1.05 and 2.67 kW compared to the European reference conditions. In addition, a factorial analysis was performed to cover a broader range of environmental conditions. The findings were used to develop a methodology to calculate vehicle-specific CO 2 emissions under different on-road conditions by utilising the vehicle's reference emissions.