Evaluating the performance of outdoor shading devices on human thermal comfort in hot humid climates: A case study of Dhahran

Urban temperature rise significantly impacts human health and comfort, particularly in regions where natural shading is unfeasible. This study evaluates the cooling performance of artificial shading devices using three materials commonly applied in Saudi Arabia: Cotton Canvas, High-Density Polyethylene (HDPE), and Polyvinyl Chloride (PVC). Field measurements in the central square of King Fahd University of Petroleum and Minerals (KFUPM), combined with ENVI-met simulations, assessed various shading configurations, including coverage ratios, heights, and double-roof systems with air gaps. Cotton Canvas demonstrated the highest thermal performance, reducing mean radiant temperature (Tmrt) by over 16°C and globe temperature by over 8°C. The optimal solution was identified as a staggered double-roof system with a 100 % coverage ratio at a 4-meter height, achieving reductions exceeding 20°C in T_mrt and 8°C in PET. Additionally, a double-roof system with a 25 cm air gap provided further cooling benefits, lowering T_mrt by 1.9°C and PET by 2.2°C. Lower shading heights (4m) were found to be most effective in mitigating heat stress, emphasizing the critical role of proximity in enhancing thermal comfort. These findings underscore the effectiveness of higher coverage ratios, optimized configurations, and material properties in improving outdoor thermal environments, offering actionable design insights for hot, arid climates.