| Keywords |
Building-Applied Photovoltaic (BAPV); Air Cavity; Thermal Performance; CFD; Korean Energy Saving Design Standard |
| Abstract |
This study examines the validity of the constant thermal resistance applied to enclosed air cavities thicker than 10 mm in the Korean Energy Saving Design Standard for PV-backed building envelopes. Thermal? fluid simulations were performed using ANSYS CFX with various combinations of turbulence and radiation models. The Generalized k?ω and Discrete Transfer model combination showed the most stable convergence and was selected for analysis. Cavity thicknesses from 10 to 100 mm were investigated to evaluate thermal resistance and airflow characteristics. The results indicate conduction-dominated heat transfer below 20 mm, laminar natural convection at 30 mm, and turbulent natural convection above 40 mm. Although the thermal resistance increase converges in the turbulent regime, it does not become constant. At 100 mm thickness, the thermal resistance increased by about 52% compared with the fixed standard value, suggesting the need for a complementary evaluation approach to better reflect the thermal behavior of thick PV air cavities. |