Enhancing Thermal Comfort and Vehicle Energy Efficiency: A Simulation Study Using GT ISE + TAITherm

The automotive industry is encountering difficulties in balancing occupant thermal comfort with HVAC system energy efficiency, particularly under the hot Indian conditions, to meet user expectations and address range anxiety in electric vehicles. Front-loaded comfort-based approach simulations during the development stages have the potential to increase energy savings compared to the stages required at the end of product design. The focus of the current research targets HVAC energy consumers, such as blower flow rates, temperatures, and Cabin heaters, and investigates how these factors influence occupant overall comfort. Additionally, design elements like glass properties and the impact of solar radiation on human comfort are studied at the early concept stages to adopt an energy-based approach for comfort optimization. Simulations are conducted using GT-SUITE and GT-TAITherm software, integrated with CFD field maps platforms to obtain exact flow field predictions. The simulation results are validated with test results obtained from climatic wind tunnel experiments. Key parameters, such as relative humidity (RH), are analyzed to understand their effect on the comfort index and control strategies to maintain vent temperatures that meet comfort requirements with minimal energy consumption. The impact of solar glass properties on comfort indices is studied. To evaluate thermal comfort comprehensively, the Berkeley model provides localized insights into physiological comfort by accounting for variations in temperature and airflow, while the Fanger model assesses overall comfort parameters using predictive indices. We identified the optimal RH levels that can reduce HVAC load while focusing on localized comfort indices for occupants. This helps to go deeper into occupant comfort under multiple scenarios, including extreme temperatures, and evaluates their physiological aspects. This exercise has helped find possible areas for front-loading comfort-based vehicle development processes and pinpoint opportunities for reducing energy consumption. Furthermore, this study reduces reliance on costly physical prototype testing and accelerates the design and development of sustainable automotive solutions, addressing critical challenges in the transition to sustainable mobility.