Why Can’t You Wipe the Fog Away?
Because the moisture is not on a surface you can reach.
Modern insulated windows typically use multiple panes with a sealed space between them.
When moisture appears inside that sealed space, the insulated glass unit may have lost its seal.
Pella specifically distinguishes condensation between glass panes from ordinary interior condensation and identifies it as an indication of glass-seal failure.
Why Does the Seal Matter?
The sealed space helps create the window’s insulating performance.
Depending on the product, it may contain:
- Dry air
- Argon
- Other insulating gas
Does Fog Mean the Whole Frame Is Bad?
Not necessarily.
The issue may be isolated to the insulated glass unit.
But the complete window should still be assessed for:
- Frame condition
- Age
- Operation
- Air leakage
- Water damage
Can You Drill a Hole and “Defog” It?
That may improve appearance temporarily.
It does not recreate the original factory-sealed insulated glass unit.
When Does Full Replacement Make Sense?
If seal failure is combined with:
- Old frames
- Difficult operation
- Drafts
- Multiple failed units
a complete replacement may make more sense.
Fog Between the Panes Is Different From Condensation on the Panes.
Envirotech Exteriors can determine whether the problem is limited to the glass or whether the complete window is ready for replacement.