Comparative modeling and performance analysis of earth-air heat exchangers in hot-arid and cold-continental climates: A case study of Baghdad and Gothenburg

This study presents a novel and reliable comparative model developed using MATLAB/Simulink to analyze and design Earth-Air Heat Exchanger (EAHE) systems under two distinct climate types: hot-arid and cold-continental. The model stands out for its effectiveness, relying on climate data to evaluate system performance-making it a valuable tool for designers and researchers alike. It has been experimentally verified. Two contrasting case studies were chosen: Baghdad (hot-dry) and Gothenburg (cold continental). Experimental air temperature data were collected and used as input for simulation. The results demonstrate distinct thermal behaviors in each region. At 5 m depth, Baghdad’s soil stays hot (31.3–30.1 °C), while Gothenburg’s remains cooler and stable (12.09–11.55 °C). Performance simulations showed that the EAHE system in Baghdad achieved 602 W cooling in July and 728.3 W heating in December. In Gothenburg, it delivered 478.52 W cooling in July and 447.97 W heating in January. These results confirm higher EAHE effectiveness in hot-arid regions, with Baghdad outperforming Gothenburg by 20.5 % in cooling and 38.5 % in heating. Moreover, Pipes of 40–50 m yielded significant thermal gains-up to 13.83 °C in Baghdad and 10.47 °C in Gothenburg-without major cost increase. Notably, Baghdad showed a 24.3 % higher temperature differential, reaffirming system suitability in arid climates.