Earth air heat exchangers: a review on its exergy assessment

The Earth Air Heat Exchanger (EAHE) is an efficient and sustainable thermal energy system designed to meet the heating and cooling requirements of buildings by utilizing the renewable energy potential of the earth. By reducing dependency on conventional energy sources, EAHE systems contribute to minimizing greenhouse gas emissions and mitigating environmental degradation. This paper presents a comprehensive review of exergy analysis conducted on EAHE systems, highlighting their thermodynamic efficiency and potential for integration with other renewable energy technologies. A systematic evaluation of existing studies has been performed, and the key findings have been compiled in a structured manner. The impact of various design and operational parameters, such as pipe length, pipe diameter, air velocity (mass flow rates), ambient conditions, and soil properties, on the exergetic efficiency of EAHE systems has been critically examined. This review also discusses different methodologies used for exergy assessment and their implications for optimizing system performance. This study emphasizes the importance of exergy analysis in enhancing the overall efficiency of EAHE systems, thereby promoting energy conservation and sustainability. The insights presented in this paper will be valuable for researchers, engineers, and policymakers interested in the design, modeling, and performance evaluation of EAHE systems for energy-efficient building applications.