Condensation in between two panes of glass can ruin your window’s appearance. During home inspections we have seen this on many homes in the past and several recently. It shows itself when the windows have a foggy or misty look. Sometimes you can see the water dripping down the inside of the pane of glass. This can cause significant damage over a period of time if it’s not addressed. In the factory double-pane windows have a layer of air or argon gas pumped in between the panes prior to them being sealed. This takes up the space inside providing additional insulation and not allowing room for water vapor.
There is also an absorbent material, silica desiccant, installed to absorb condensation if it does form. When the factory seal fails, the gas is released and oxygen takes it’s place. With the oxygen comes water vapor. The silica desiccant eventually gets water logged and condensation begins to form on the inside pane of the window.
On an inspection last week there were five windows in this condition. The home buyer and seller were concerned that all these windows would need to be replaced. Fortunately, that’s not always true. In most cases the glass assembly can be changed and only in rare cases must the entire window be replaced. There are also methods to repair the window without replacing anything. A small hole is drilled into the glass and a cleaning solution is pumped in between the panes. This and all other moisture is then sucked out and a valve put in place to allow the window to breath.
The bottom line is there are options available if your windows have fogged up. It may not be necessary to replace these windows. A less expensive option may available.