Design, Development and Thermal Performance Analysis of Ultra-Low Heat Loss Triple Vacuum Glazing

Heat loss through windows of buildings is one of the significant causes of high-energy consumption that require intervention to advance their thermal performance in a move towards net-zero energy buildings. High-performance triple vacuum glazing features ultra-low heat loss that maintains the transparency, regardless of tiny pillar spots, and slimness due to its narrow evacuated cavities. This study reports the design and development of high-vacuum system with the modified vacuum cup which provides an effective pump-out hole sealing and has an achievable vacuum pressure of 4.02x10-5 Pa. A new dual-edge seal (low temperature melt 186˚C) consists of Cerasolzer CS186 alloy as a main and J-B Weld epoxy steel adhesive as a support seal is developed and the triple vacuum glazing (area of 300 x 300mm) samples are fabricated, in which the vacuum pressure of 4.8x10-2 Pa is achieved. A 3D FEM of the fabricated triple vacuum glazed is developed and the centre-of-pane and overall U-value of 0.33Wm-2K-1 and 1.05 Wm-2K-1, respectively, are predicted.