Impact of support pillars geometry on thermal insulation performance of vacuum glazing: CFD research and exergy analysis

Abstract

Vacuum glazing technology is based on evacuating the gas between the double glasses and aims to prevent heat losses by eliminating convection effects. This study evaluates the effect of thermal conductivity and column design on the window heat transfer coefficient with a 2D CFD study, taking 200 x 350 mm vacuum glass as a reference. The effect of changing the glass thermal conductivity between 0.1-0.4 W/mK on the window heat transfer coefficient (Uw) is analysed. For thermal conductivity of support pillars, solutions in the range of 0.04-0.20 W/mK are taken. Model results are evaluated for convergent and divergent column design. The reference Uw value of 1.21 W/m2K was determined as 0.76 W/m2K in the converging cylindrical column design and 0.92 W/m2K in the divergent one.