Thermal Performance of Glazing vs Insulated Curtain-Wall Panels in Hot-Arid Urban Environments: Implications for Climate-Adaptive Façade Design

The thermal performance of glazed façade systems is a key driver of building energy demand and indoor thermal comfort, particularly in hot climates. This study numerically evaluates steady-state heat transfer in a representative uPVC-framed window/curtain-wall-like glazed façade section detail by comparing two infill configurations: (i) an opaque insulated infill panel and (ii) a gas-filled double-glazed unit (DGU) including the edge/spacer region. A two-dimensional finite-element model was developed in COMSOL Multiphysics and formulated in accordance with ISO 10077-2:2012 to extract the section thermal conductance, L 2D , the frame thermal transmittance, Uf (insulated-panel case), and the linear thermal transmittance, \(\:ψ\:\) (DGU case). Under Madinah summer boundary conditions (Ti = 24°C, Te = 45°C), the insulated-panel configuration yielded \(\:{L}2D=0.240\)W/(m·K) and \(\:{U}f=0.405\:\)W/(m²·K), with a negligible linear thermal transmittance \(\:ψ\:≈\:0.00\)W/(m·K). In contrast, the DGU configuration increased the section conductance to \(\:{L}2D=0.352\)W/(m·K) and produced \(\:ψ\:=0.061\)W/(m·K), indicating a measurable edge thermal bridge at the frame–glazing junction. These findings provide quantitative guidance for façade selection strategies in hot-arid urban environments, contributing to energy-efficient land development and climate-adaptive building design in rapidly urbanizing regions. In cooling-dominated cities characterized by extensive glazed high-rise developments, heat transfer or heat gains can accumulate at the district scale, influencing urban energy demand and resilience to extreme heat.