If the fog is between the glass, you cannot simply "caulk it shut." To truly reseal a double-pane unit, the glass must be removed, the old seal stripped away, the interior panes cleaned/dried, and a new seal applied in a factory-controlled environment.
Restores full energy efficiency; much cheaper than a full window replacement. Cons: Requires professional measurement and installation. Full Window Replacement resealing double pane windows
because it is nearly impossible to remove 100% of the moisture at home. If even a tiny bit of humidity remains, the window will fog up again within weeks. Solutions for Blown Seals Defogging (The Budget Option) If the fog is between the glass, you
Resealing double pane windows offers several benefits, including: the glass must be removed