Todd H. wrote:

"FDR" writes:

When the seal breaks, the argon gas that is normally sandwiched in between
the panes will escape rendering the insulation value to nearly
nothing.

Which, it bears mention, is only slightly worse than the insulation
value of argon gas! Gas is not a terribly good insulator.

It's not bad. Neither is air.

http://www.farleywindows.com/perform..._canadian.html

shows a low-e and argon combination raises the US R-value of double glass
by about 1, from 2.04 to 2.86. Neither are "nearly nothing," altho they
are small, compared to an R30 wall.

Nick