An indium-based seal augmented with an adhesive, developed to maintain
a vacuum between two sheets of glass, avoids the high temperatures re
quired to produce a seal in evacuated glazings to date. An experimenta
lly-validated three-dimensional transient model has been used to predi
ct heat transfer for an indium/adhesive sealed 1 m(2) area evacuated w
indow with a highly insulating frame. An overall heat loss coefficient
of 0.9 W m(-1) K-1, with a midplane value of 0.36 W m(-2) K-1, can be
achieved with 0.72 visible transmittance for two 6 mm panes separated
by 0.2 mm diameter pillars 40 mm apart. The conduction through a 3 mm
edge-seal was 1.14 W m(-2) K-1. Detailed three-dimensional isothermal
contour plots through the system are presented. (C) 1998 Elsevier Sci
ence Ltd. All rights reserved.