[quote=Hobie]Appears just the seal went bad. These windows are not in a vacuum or contain inert gas.

From the outside they will remove the outside single pane, clean window, reseal and reinstall old glass.[/quote]

Just curious. How can you tell they aren’t vaccuum sealed or doesn’t contain inert gas?

I had a small bathroom sliding window that also fogged. I took a drill and put a tiny hole in the top and bottom. And then I left the window in a hot car. After the fog cleared I dropped small dessicant pellets in the bottom and plugged both holes. Hasn’t fogged since. Can’t do the same thing to this window though