Why Your Windows Are Foggy Between the Panes
Condensation on the inside surface of your window is a humidity issue. Moisture trapped between the two panes, where you cannot wipe it off, is something else entirely.
Condensation on the inside surface of your window is a humidity issue. Moisture trapped between the two panes, where you cannot wipe it off, is something else entirely.
Your window is an insulated glass unit: two panes of glass with a sealed, usually gas-filled space between them, held apart by a spacer around the edge. That seal has failed. Outside air carrying moisture is now getting into the cavity, condensing on the cold surface, and it has nowhere to go.
The fog itself is a symptom. The real loss is the insulating gas that used to be in that space, which has been leaking out since the seal opened. The window is still a window. It is just performing closer to a single pane now.
You will usually see it on south and west elevations first. Those get the most heat cycling, and heat cycling is what works the seal loose over years.
Often, yes, and this is the part most companies will not tell you.
In many cases the insulated glass unit alone can be replaced while keeping your existing frame and sash. That is a materially cheaper job than replacing the whole window, and if your frames are in good shape it is frequently the right call.
Two things have to be true: the frame and sash need to be sound, and the unit needs to be one that can still be sourced or fabricated to match. On most windows from the last thirty years, both are usually true.
Defogging services that drill the glass and vent the cavity exist. We do not recommend them. They clear the visible fog without restoring the seal or the gas fill, so you have paid to make a performance problem invisible.
We are not going to put a number on this page, and we would rather tell you why than pretend.
Fog between the panes can be a glass unit replacement on a perfectly good window, or it can be the visible symptom of a window that is finished. Those are very different jobs at very different prices, and nobody can tell which one you have from a web page. Anyone who quotes you a repair price sight unseen is quoting a guess and hoping you anchor to it.
Here is the part that makes this not a stalling tactic: repair moves fast. A repair visit is a look, a diagnosis, and a number. Not a four hour presentation. Where glass has to be ordered we will tell you the actual timeline at the quote instead of guessing at it now.
Then you decide. No deposit to get a number, no pressure to schedule at the door, and you tell us when to start.
If you have one foggy unit in a house full of healthy windows, we will tell you that and quote the repair, even though the whole home quote would be worth more to us. If you have fifteen fogging units in a 1978 house, we will tell you that too.
No deposit to get a number, no four hour presentation, and you pick the start date.