quote:

Originally posted by Schmelby:
Most window makers use nitrogen instead of argon, much cheaper. One company had a couple cylinders of Krypton but it was stupid expensive.

But well worth it if you don't want Superman busting into your house! Next thing you know, your daughter's knocked up, and money's missing off the dresser, seen it a hundred times!

I doubt that it matters much what inert or other gas is inside the "sandwich." What matters is that there is no convection happening as through a single pane. I suppose conduction might be reduced too.

My experience in these matters is mostly with ~ 4' x 6.5' double-pane "sandwiches" used for patio doors. The window shop I last used built these at their shop and brought them whole to the home site where they were inserted into the Al door frame. I didn't ask what gas they pumped between the panes. I lose far more heat around the edges of the door and frame than through the glass.