Experimental investigation on heat transfer analysis of open loop shallow geothermal combined thermally activated building structure in a semi-arid region

Balaji Thiyagarajan, Balaji Kumar

The increase in temperature and population would result in an expansion of building areas, the use of traditional cooling, and energy usage, leading to carbon dioxide emissions in semi-arid regions. Shallow geothermal power is currently the most power-efficient and lowest greenhouse gas alternative for room cooling and heating. This study examines an open-loop shallow geothermal combined thermally activated building structure (GeoTABS) to determine how indoor surface heat flux varies under different cooling strategies tailored for tropical climates. System involves embedding pipes within the building framework to control surface temperatures, thereby enabling cooling in conditioned areas. This study presents a novel design of a GeoTABS system, analyzing the impact of Indian cooling climatic conditions on heat transfer and the indoor ambient features of the systems inside surfaces. Without ventilation, the ceiling was the main route for heat transfer into the room starting at 11:00 h, while the all-surface cooling functioned as cooling surfaces, inhibiting heat transfer into the space with a net average heat flux of 10.5 W/m 2 . Introducing natural ventilation led to non-uniform potential and heat distribution for localized heat spikes on the walls, especially during the peak hours. Initially, floor and wall temperature owing to convective cooling, then dropped as the combined effect of GeoTABS cooling took over, before increasing once more with the growing influence of thermal inertia and solar radiation absorption.