Reviewed by Lexie CornerMar 3 2025
A recent review article published in Engineering provides a comprehensive overview of vacuum glazing, a technique that could significantly improve building energy efficiency. Since buildings account for about 40 % of overall energy use, improving the thermal performance of glazing is crucial for meeting low-carbon building targets.
Graphical abstract. Image Credit: Jinqing Peng et al.
Vacuum glazing has gained attention for its ability to retain heat, provide sound insulation, be lightweight, and resist condensation. The concept originated in 1913, but it wasn't until 1989 that Australian researchers developed vacuum glazing with exceptional thermal insulation properties. Since then, its development has advanced significantly.
The review explores various aspects of vacuum glazing, including fabrication procedures, support pillar layouts, composite constructions, research methods, and energy efficiency. The three main manufacturing methods are solder glass edge sealing, vacuum chamber edge sealing, and pump-out edge sealing.
Each method has its advantages and disadvantages, but the modified pump-out approach seems the most promising. It addresses the limitations of high-temperature deterioration in the glass powder sealing method and insufficient outgassing in the vacuum chamber method.
Support pillars are critical for maintaining the vacuum gap and withstanding external pressure. Their design must balance mechanical strength and thermal performance. Composite vacuum glazing, including hybrid, triple, and PV vacuum glazing, has also been developed. Triple vacuum glazing has a very low U-value, indicating strong insulation performance, while PV vacuum glazing generates clean power using solar radiation.
Researchers use analytical, numerical, and experimental methods to assess the thermal performance of vacuum glazing. These approaches help in understanding heat transfer and determining the effect of various parameters on the U-value, such as glass type, vacuum level, and low-E coating emissivity.
The energy-saving potential of vacuum glazing varies based on building design, climate, and other factors. Triple vacuum glazing is particularly effective at reducing heat loss in extremely cold temperatures. PV vacuum glazing can significantly improve energy efficiency in areas with high solar radiation. Tinted vacuum glazing is suitable for regions with substantial seasonal heating and cooling demands.
Journal Reference:
Peng, J. et. al. (2025) Excellent Insulation Vacuum Glazing for Low-Carbon Buildings: Fabrication, Modeling, and Evaluation. Engineering. doi.org/10.1016/j.eng.2024.11.027