The panes of glass in an insulating unit must be kept apart
at the appropriate distance by spacers. In addition to keeping the glass panes
separated, the spacer system serves a number of other functions:
• Accommodate stress induced by thermal expansion and
pressure differences;
• Provides a moisture barrier that prevents passage of water
or water vapor that would fog the unit;
• Provides a gas-tight seal that prevents the loss of any
special low-conductance gas in the air space;
• Creates an insulating barrier that reduces the formation
of interior condensation at the edge
