Multi-parameter thermal performance and investment cost analysis of opaque ventilated facades in hot-humid climates

Heat gains and losses through facade components significantly impact total energy consumption over a building's lifecycle. In hot-humid climates, where summer cooling demand is rapidly increasing due to global warming, high-performance building envelope design is critical. Although opaque ventilated facade (OVF) systems offer notable passive cooling potential, no comprehensive parametric study simultaneously addresses vent configuration, facade orientation, cladding material, joint typology, insulation layer, and cost. This study examines these parameters through a systematic CFD approach for Turkey's hot-humid climate zone. A total of 126 ANSYS Fluent simulations evaluated the effects of facade orientation, cladding material, joint typology, and insulation layer on thermal performance. Results indicate that OVF application should be prioritized on south- and west-facing facades. Clay-based cladding reduces interior heat transfer by 40% compared to alternatives. The open-joint bi-directional outlet vent configuration (F2-K3) increases cavity air velocity by approximately 1 m/s, strengthening the chimney effect, and reduces heat transfer to the interior by 64% relative to the unventilated reference facade. Thermal and economic analyses demonstrate that, within the defined design parameter space and the set of configurations investigated in this study, F2-K3 delivers the highest thermal efficiency at the lowest construction cost (139.14 USD/m²). These findings provide designers with a numerically grounded guide for reducing cooling loads and improving thermal comfort in hot-humid climates.