Thermal Performance of Window with Vacuum Glazing. Case Study

Abstract

This document deals with the determination of thermal transmission properties of wood-aluminium window with vacuum glazing. Test measurements are performed with guarded hot-box method at defined temperature difference. They describe how the support pillars influence temperature distribution on the surface and how the edge vacuum glazing influence the heat flow through window. The deformation of the temperature field due to support pillars is surprisingly small and its range is from 0.40 K to 0.51 K with temperature difference on both sides of approximately 33 K. Decrease of internal surface temperature from the middle of glass to the edge is about 18.92 °C – 12.37 °C = 6.55 K, and so it is considerable effect. The effect of the edge on the glazing is not explicitly quantified in the term of heat flow in this document, but is implicitly documented by means of surface temperature. Thermography was used to check if there are touching points between glasses where distance is from 0.15 to 0.2 mm. The vacuum glazing measured in this work was a sample, which was fabricated in Asian producer. The window was tested two years after delivery from the producer.