This is one of the most common myths that keep homeowners from replacing their windows. They feel that if their windows are double pane, they are fine and working efficiently, no matter how old they are. The fact is older double pane windows are simply two panes of glass that were set in the frame to create an additional air-gap barrier that reduces some energy transfer.
Replacement window technology of today has advanced so far in the past twenty years, that older double pane windows are highly inefficient compared to today’s double-pane windows. Special technology advancements like gas fills, spacers, films, and specially formulated seals create a highly efficient window that prevents sound and energy transfer, along with blocking certain harmful light rays.
Few, if any of these are found in older double pane windows. And chances are, your older windows have broken seals and perhaps condensation. Replacing them will reduce energy usage, protect your furniture from the sun’s rays, and quiet your home from outdoor noise.