Many homeowners  believe that  because they already have dual pane windows that they do not need to replace them.

That fact is that many dual pane windows are not  energy efficient.

Many  homes have aluminum framed dual pane windows, which are not energy efficient. Most were made before the newer technology was available. Aluminum is a conductor of heat and cold and thus not energy efficient. Most of the old aluminum dual pane windows do not have  low e glass, plus they have the old aluminum spacers between the  panes which conduct heat and cold.

Many homeowners have vinyl dual pane windows that also are not energy efficient. This is because most builders installed windows that barely met the code of .40 ufactor and .55 shgc (old Energy Star requirements) Most of them  also had aluminum spacers between the panes which also  conducted heat and cold. The result is that they have dual pane windows that are really not very energy efficient.

To emphasize the point that most older dual pane windows, either aluminum or vinyl are not very energy efficient, consider this….. the newer energy star rated windows .30 u factor and .30 Shgc are at least 25 % more energy efficient   than the older vinly ones and  about 50-75 % more energy efficient than the older aluminum ones.

Therefore, if you believe that just because you have dual pane windows you do not need to consider changing them, perhaps you need to at least  get some more information.

www.northwestenergysavers.com  download free report “Things you need to know about windows before you buy “