CFD Modeling of a Semi-transparent PV-PCM Façade Window with Embedded Water Cooling

Urban decarbonization can benefit from façades that both generate power and manage heat. This study examines a semi-transparent PV glazing coupled with a phase-change layer (PCM, ~25 °C melt) and an embedded water loop as a tri-functional façade element suitable for dense cities. A steady state CFD was built with radiation baseline (pressure-based RANS, k–ω SST viscous model, fully conjugate heat transfer) with Discrete Ordinates in participating media to resolve solar transport through PV–PCM–glass and quantify heat flux partitioning. At a summer design point, the sunlit face absorbs ~780 W/m² on average; ~200 W/m² are rejected immediately to ambient (~21% radiative, ~79% convective), while the remainder is routed into the laminate. Results show strong cooling footprints over the serpentine on the PV side and “cold stripes” on the room side (~12–31°C), evidencing effective heat draw toward the coil and reduced indoor loads. Water-side removal derived from outlet temperature yields ~190 W for the numerical simulated panel, and a closed local energy balance corroborates the optical–thermal setup. This study delivers design-relevant metrics (PV operating temperature, exterior/room-side fluxes, useful heat recovery) and highlights levers, like coil pitch, PCM thickness, flow rate, and film coefficients.