Automotive air-conditioning system thermal performance assessment: an experimental approach combining first and second laws of thermodynamics

Thermal comfort is a key requirement in passenger car design. However, automotive air-conditioning (AC) systems increase vehicle fuel consumption and contribute to greenhouse gas emissions. As a result, various studies have focused on identifying refrigerants with lower environmental impact and improving AC system efficiency. Most of this research, however, has primarily examined the energy consumption of the compressor, neglecting the auxiliary components. This study aims to experimentally analyze the thermal performance of an automotive AC system, taking into account the power consumption of auxiliary components, such as fans and the compressor clutch, and assessing their impact on overall system performance. The analysis of the experimental data is based on the first and second laws of thermodynamics, enabling the evaluation of cooling capacity, total power consumption, and the irreversibilities associated with the main components of the AC system. Results show the importance of considering the auxiliary components when evaluating the thermal performance of an automotive AC system. Furthermore, the concept of entropy generation was employed to prioritize the system components under investigation, highlighting the compressor and condenser as having the most significant potential for improvement.