15 year old windows.. repair or replace ?

[Joel Owens]

There is a house I am looking at. House built in 1998. Great shape but I saw condensation through the double pane windows.

I Googled windows with moisture and this came up.

http://windowmedics.com/restore/

I have never heard of venting a window to solve this problem. Has anyone tried this or had success with it??

It says it can be almost 75% cheaper than replacement. I bet that is retail pricing though and if I found new windows for a great deal and labor the savings would be nominal. That is why I am still leaning toward window replacement versus venting.

Any thoughts appreciated......