This paper describes the first long-term field tests done on vacuum gl
azing. In this preliminary study, glazing samples were mounted in an o
utdoor environment and observed for more than one year. The effects of
large temperature differences and thermal cycling on the thermal perf
ormance and the mechanical stability of the glazings have been investi
gated. The results provide support for the viability of vacuum glazing
s in their intended application as thermally insulating windows. (C) 1
997 Elsevier Science Ltd.