Vacuum glazing: Current performance and future prospects

The development of vacuum glazing is a significant advance in the area of low heat loss glazing systems with great potential to reduce building heating and when combined with solar control glazing, cooling loads. The basic concept of vacuum glazing is reviewed and the procedures and research undertaken in the development of both high-temperature and low-temperature sealing of vacuum glazing are outlined. The achieved thermal performance of current laboratory systems and those that are now commercially available are presented. The potential levels of performance that may be achieved using high-performance low-emittance (low-e) coatings and tempered glass are reported. Research into window systems that incorporate vacuum glazing to achieve improved thermal performance is also outlined.