Enhancing thermal efficiency of passive solar heating systems through copper chip integration: experimental investigation and analysis

This study aims to upgrade the thermal performance of a passive solar system, specifically a Trombe wall (TW), by incorporating a metallic absorbent made of copper chips into its absorbent surfaces. The paper compares the thermal performance of a classic TW with that of a copper chip-enhanced TW. An experimental test was set up for classic and copper chip-TW systems, and a full-day experiment was conducted in January 2018 to investigate the thermal performance under the same operating conditions. The experimental data were used to verify a mathematical model based on energy balance. The theoretical study agreed well with the experimental data, with a maximum error of 11% in the absorbent surface temperature valuation. The results revealed that adding copper chips to the TW system boosts its performance by increasing heat gains and improving thermal efficiency. It improves thermal efficiency and enhances the mean room temperature by 12.44% and 14.1%, respectively.