Comparative analysis of the heating performance of a hybrid Trombe wall System with Earth air heat exchanger in a cold climate condition

• The Earth-Air Heat Exchanger and Trombe Wall systems are evaluated for their thermal performance. • Thermal comfort is assessed using the widely recognized Predicted Mean Vote (PMV) index. • Different scenarios are analyzed and discussed through detailed CFD simulations. • The relative humidity levels were higher in houses equipped with Trombe walls compared to those utilizing combined systems.The OEAHE-TWall and CEAHE-TWall systems provide thermal comfort for approximately 30% of the study period. Air conditioning systems significantly contribute to global energy consumption and carbon dioxide emissions, highlighting the urgent need for passive energy solutions. This study evaluates the performance of open-loop and closed-loop Earth-to-Air Heat Exchanger (EAHE) systems, integrated with Trombe walls, to enhance thermal comfort in residential buildings in cold, dry winter climates. Results indicate that combined Trombe wall and EAHE systems effectively maintain indoor thermal comfort without supplementary heating. On days with outdoor temperatures below -10°C, the combined systems achieved indoor temperatures of 7°C to 17.5°C. For temperatures between -10°C and 0°C, indoor temperatures ranged from 8.7°C to 29°C. However, on warmer winter days (4.5°C to 22.5°C), the Trombe wall alone outperformed the combined systems, maintaining indoor temperatures of 20°C to 28.5°C, aligning closely with thermal comfort standards. Thermal comfort was ensured by the integrated systems for approximately one-third of winter days. CFD simulations revealed that adding a fan increased flow velocity from 0.2 m/s at the channel inlet to 1 m/s at the outlet, with a 1°C temperature rise through the underground channel. These findings show the potential of Trombe wall and EAHE systems as sustainable solutions for improving thermal comfort in cold climates while reducing dependence on conventional heating.