This study presents a comprehensive numerical investigation of a concrete solar collector (CSC) integrated into building roofs as an effective passive cooling strategy for hot and arid climates. The research evaluates the influence of key design and operational parameters namely: water mass flow rate, embedded pipe depth, and pipe-to-pipe spacing on the internal roof surface temperature and overall thermal performance. A three-dimensional computational fluid dynamics (CFD) model was developed using SolidWorks Flow Simulation (2022) and validated against previously published experimental data, demonstrating strong agreement and reliability. Parametric analysis was conducted for mass flow rates ranging from 0.007 to 0.028 kg/s, pipe depths between 4 and 16 cm, and pipe spacings of 10, 8, and 6 cm. The results reveal that increasing the mass flow rate significantly enhances heat removal, with an optimal value of 0.014 kg/s achieving a maximum reduction of 17.7% in internal roof surface temperature while maintaining moderate pressure losses. In contrast, pipe depth exhibited a relatively minor effect on thermal performance. Reducing pipe spacing improved heat transfer efficiency, decreasing the internal surface temperature from 30.3°C to 28.4°C and increasing outlet water temperature from 27.5°C to 30°C. Additionally, empirical correlations were developed to predict internal roof surface and outlet water temperatures with accuracies of 97.31% and 95.32%, respectively. The findings highlight that optimized CSC configurations can effectively reduce solar heat gain, enhance indoor thermal comfort, and lower cooling energy demand. This study provides practical design guidelines for integrating CSC systems into building envelopes, supporting sustainable and energy-efficient construction in hot and semi-arid regions.
Jasim et al. (Wed,) studied this question.