Written by Big Easy Windows
Key Takeaways
- Haze or moisture trapped between the panes means the insulated glass unit’s perimeter seal has failed. You cannot clean it, because the surfaces are sealed inside.
- Gulf heat drives the failure. Daily expansion and contraction cycles work the seal, and our humidity supplies plenty of moisture to be drawn in.
- West and south-facing glass fails first, because those units run the hottest.
- You can often replace just the glass unit and keep the frame, which costs less than a whole window.
- Big Easy Windows handles glass unit replacement and full window replacement. Call (504) 384-8165.
What You Are Actually Looking At
Quick Answer: A modern window has two panes separated by a spacer and sealed around the perimeter, with the cavity filled with dry air or an inert gas. When that perimeter seal fails, humid outside air gets into the cavity. As the glass heats and cools through the day, moisture in that trapped air condenses on the inner glass surfaces. That’s the haze, and it’s inside a sealed assembly, so no amount of cleaning touches it.
Homeowners across Kenner and Covington often assume it’s a cleaning problem for a season before realizing what it is. The giveaway is that it comes and goes with temperature and never wipes off.
Why It Happens Faster Here
Insulated glass seals fail everywhere. They fail sooner in our climate for three reasons that compound.
Thermal cycling. Glass in direct sun gets very hot, then drops when a thunderstorm rolls through or the sun goes down. The sealant and spacer expand and contract with every cycle. Our long, intense cooling season delivers a lot of cycles.
Available moisture. Once the seal is compromised, the desiccant inside the spacer absorbs incoming moisture until it’s saturated. In sustained high humidity, that happens faster than in dry air.
UV exposure. Sunlight degrades sealants over time, and our UV load is significant.
This is why the failures cluster on the west and south elevations. Homeowners frequently report one wall of foggy windows while the north side looks fine, and that’s exactly what you’d expect.
Not All Condensation Is Seal Failure
Location tells you which problem you have:
- Between the panes. Seal failure. Nothing you do inside the house fixes it.
- Inside surface, facing the room. Indoor humidity meeting cool glass. It’s an air and moisture management issue, covered in ways to reduce condensation.
- Outside surface. Usually dew on cool glass in the morning. Harmless, and often a sign the glass is insulating well.
Try to wipe it. If it clears, it isn’t a seal failure.
What It Costs You Beyond Appearance
A failed unit loses insulating performance, since any inert gas fill has escaped and moisture conducts heat. The loss is real but usually modest compared with the visual problem and the eventual staining, where mineral deposits etch the inner surfaces permanently.
The bigger issue is what it signals. A window failing at 8 years is telling you something different from one failing at 25. If several fail together on a house of the same vintage, you’re likely looking at the whole set aging out rather than isolated defects. Our post on how long replacement windows last in Louisiana covers realistic service life here.
Repair the Glass or Replace the Window?
Glass Unit Replacement
The sealed unit is removed and a new one fitted into the existing sash and frame. This makes sense when the frame and hardware are in good shape, the window is relatively young, and only a few units have failed. It’s the cheaper path.
Match the glass package when you do it. Putting clear glass into a house that had low-E creates a hot room and a visibly different pane. Our guide to reading a window energy label explains what to specify.
Full Window Replacement
Makes more sense when the frames are failing too, hardware is worn, many units have gone at once, or the windows are old enough that replacing glass is money into a unit that’s near the end anyway. It’s also the moment to reconsider performance and, if relevant, impact-rated glass.
Our comparison of window repair or replacement walks through the decision.
Is It Under Warranty?
Worth checking before spending anything. Insulated glass units usually carry their own warranty term, often separate from the frame warranty, and seal failure is the classic covered defect. Find your paperwork, note the installation date, and contact the manufacturer or the original installer. Coverage may be prorated and may not include labor, but it can still cut the cost meaningfully.
Frequently Asked Questions
Can foggy glass be fixed by drilling and drying it?
Services exist that drill, dry, and vent the cavity. It can improve appearance. It does not restore the sealed unit or any gas fill, and etching already on the glass stays.
How long should a seal last?
It varies by product quality, exposure, and installation. Our heat and UV shorten it compared with milder climates, and sun-facing elevations go first.
Can I replace one pane only?
No. The unit is a sealed assembly, so the whole unit gets replaced, not one sheet of glass.
Does it mean my windows were installed badly?
Not necessarily. Seal failure is usually a product and exposure story. Installation matters more for water intrusion and air leakage, covered in our installation process.
Should I replace all the windows if a few fogged?
Not automatically. If they’re relatively new, replace the failed units. If the whole set is aging and several went at once, price both paths.
Get the Failed Units Looked At
We’ll identify which units have actually failed, check whether frames and hardware justify keeping them, and quote glass replacement against full replacement so you can compare.
Big Easy Windows serves the New Orleans metro and Northshore. See window repair or call (504) 384-8165.
