Optimizing Biological Resilience in Passive Solar Aquaponics: A Synergistic Approach to EAHE-Based Thermal Buffering and Gaseous Exchange Dynamics

The requirement of energy efficiency in designs of sustainable aquaponics has brought about the incorporation of passive solar systems and earth–air heat exchangers (EAHE). In this study, an evaluation of the physiological effects that arise from the implementation of the use of underground thermal stabilization by means of heat exchangers and the limitations of this technology will be carried out. The greatest strength of this technology is the “thermal buffer” that is created in the physiology of the fish; this technology makes the fish resilient to changes in environmental temperatures, thus reducing energy usage. However, the weakness is that there are ecological risks involved, such as moisture build-up due to low air exchange and biofilm formation in pipes, which occur when this technology is used without biological controls. This review highlights the critical balance between energy efficiency and biological safety while analyzing the impacts of these technological advantages on growth performance, metabolic regulation, and physiological stress responses in fish. This review demonstrates that, beyond improving heating and cooling efficiency, successful implementation of EAHE-assisted passive solar aquaponics depends on balancing engineering performance with biological requirements, including thermal regulation, gas exchange, humidity control, and biosecurity.