This study investigates the performance of solar chimney systems as a passive cooling solution for buildings in hot arid climates. A combination of experimental and computational simulations was employed to analyze the impact of various chimney size configurations on indoor air temperature and cooling energy consumption. Results demonstrated that the incorporation of a solar chimney reduced mean indoor air temperature by up to 1.53 ℃ (5.3%) compared to the base case without solar chimney and achieved a 3% reduction in energy demand over the summer period. Among the 25 configurations tested, the optimal design, featuring a width of 38 cm and a height of 155 cm, achieved the best performance. This design also demonstrated scalability, with a width-to-height ratio of 1:4.08 and compatibility with typical room dimensions. Computational Fluid Dynamics (CFD) analysis validated the improved airflow dynamics of the optimized configuration, highlighting its potential for enhancing natural ventilation. The findings underline the effectiveness of solar chimneys as a sustainable and versatile design strategy for improving energy efficiency and indoor thermal comfort in residential, commercial, and institutional buildings in hot arid environments.