Cabin Insulation as a Key Factor for HVAC System Performance and Efficiency in Electric Vehicles

Abstract

Cabin insulation is a key factor for HVAC system performance and efficiency in electric vehicles. Both on hot summer and cold winter days, the HVAC system of an electric vehicle faces significant challenges: - As the peak power of an electric compressor is limited, fast cool-down of a hot-soaked cabin under high solar loads can push the AC system to its limits - The high-energy consumption in these high-load operating points has a strong impact on the vehicle range - In winter, the effort for cabin heating can become even higher, both due to fresh air requirements and high-temperature gradients between warm cabin interior and cold ambience In a joint project, Magna ECS and Honeywell have investigated the impact of cabin insulation under these conditions. Based on an existing baseline-vehicle simulation model, we added an insulation layer inside all cabin walls (except windows). We then compared the WLTC (Worldwide harmonized Light vehicles Test Procedure) vehicle range prediction for cases with and without added insulation. We also compared cabin cool-down and warm-up times. The results show that cabin insulation can contribute significantly to more efficient electric vehicles.