EcoRenovator - fill window with propane

re:
I'm getting condensation between the panes:

Civil question so I'll give you a civil answer:

1. depends on how long you have noticed it 'fogged'
If just recent, very carefully drill a 1/16" dia hole thru the edge thru the spacer - one near the top, the other near the bottom, dont hit the glass or you wil likely crack it. The 'fog' will clear up in a few days.
If ambitious, you can inset a small tube and blow in dry N2, CO2, Argon from a welding bottle, or even propane, then seal with butyl. You can also drill a hole in the glass at top and bottom with a cheap 1/4", $5 harbor freight diamond cup drill, reseal with duct tape if you like. Outside or inside depending on your climate - outside in Phoenix, inside in Seattle ,etc

2. If it has been 'fogged' for a few months or more, you can get rid of the condensation by the above method but the internal moisture will have reacted with the glass forming silicates that wont evaporate off, and longer can form enzymes that literally ETCH the glass inside - it will always looked fogged, even if you strip the panes apart, you cannot clean them without abrasive polish.