Comprehensive review on climatic feasibility and economic benefits of Earth-to-Air Heat Exchanger (EAHE) systems

An Earth-to-Air Heat Exchanger (EAHE) is a shallow geothermal system that utilizes ambient air as the working fluid to directly provide fresh air and heating/cooling capacity for buildings. EAHE systems have gained considerable attention because of their low maintenance operations and straightforward design. A literature review was conducted to reveal the climatic feasibility, energy-saving potential, indoor thermal comfort, hybrid system, and economic benefits of EAHE systems. Special attention is paid to describing the aspects of climatic feasibility and economic benefits, because these are the key parameters influencing the extent to which EAHE systems can be applied in practical projects. This review will not only deepen reader understanding of EAHEs from a techno-economic perspective but also offer practical strategies for the application of EAHE systems in an efficient and effective manner.