Foggy Windows in Kelowna: Can a Failed Sealed Unit Be Fixed, and What Does It Cost?
There is a specific kind of haze that no amount of cleaning touches. You wipe the inside, you wipe the outside, and the milky film is still there, sitting in the middle of the glass like the window has clouded over from within.
That is a failed insulated glass unit, and it is one of the most common window complaints in Kelowna. Here is what actually happened, what can be done, and what it costs.
What a sealed unit is and how it fails
A modern window is not one piece of glass. It is an insulated glass unit: two, sometimes three, panes separated by a spacer bar, with the cavity between them sealed and usually filled with an inert gas such as argon. Inside the spacer is a desiccant, a drying agent that absorbs the small amount of moisture present when the unit is assembled.
The unit works as long as the seal holds. When the seal fails:
1. The gas fill escapes and is replaced by outside air.
2. That air carries moisture in and out with every temperature swing.
3. The desiccant saturates and can no longer absorb it.
4. Moisture condenses on the inner surfaces of the glass where you cannot reach it.
5. Over time it leaves mineral deposits and permanent etching.
The window still works as a window. It is weathertight, it still keeps rain out. What it has lost is a meaningful part of its insulating value, its clarity, and often its appearance from the street.
Why this happens so much in Kelowna
Seal failure is driven by thermal cycling and by UV degradation of the sealant, and this valley delivers a lot of both.
Large daily temperature swings. The Okanagan's dry climate means big differences between afternoon and overnight temperatures, in summer especially. The gas inside the unit expands and contracts with each cycle, and the seal flexes each time.
High UV exposure. Long, intense sun degrades the perimeter sealant, particularly on south and west elevations.
Direct solar load. A south facing window in full August sun gets very hot. Add a dark blind or a heavy curtain close to the glass and heat builds between the covering and the window, which stresses the seal harder still.
The result is a pattern almost every Kelowna glass company sees: the south and west windows fail years before the north ones. If a few of your windows have gone and they are all on the same side of the house, that is not a coincidence and it is not a defect in those particular units.
Can it be repaired?
There is a defogging service that exists in the market: drill small holes in the glass, clean or flush the interior, and fit a vent or valve. Honest assessment of it:
- It can improve the appearance where the haze is condensation rather than permanent mineral etching.
- It does not restore the gas fill, so the original insulating performance does not come back.
- It leaves the cavity vented rather than sealed.
- If the glass is already etched or the coating is damaged, it does not help.
For a window that will be replaced within a few years anyway, or in a location where appearance is all that matters, some people find it worthwhile. For a permanent fix, the sealed unit gets replaced.
The real choice: glass only or whole window
This is where most of the money is decided, and a lot of homeowners are quoted a full window replacement when they did not need one.
Replace the glass unit only, keeping the existing frame and sash, when:
- The frame and sash are sound, not rotted, not distorted, and operate properly.
- The hardware works.
- Only the sealed unit has failed.
- You are happy with the window style.
This is a considerably cheaper job and it is often done in a day. Depending on the window, the glass can sometimes be changed in place; on other units the sash comes out, goes to the shop, and comes back.
Replace the whole window when:
- The frame is damaged, rotted, or is a vinyl unit that has warped.
- The window no longer operates or seals properly at the sash.
- You want a different style, size or operation.
- Multiple windows are failing and you want to upgrade the whole assembly's performance while the work is happening anyway.
2026 cost ranges in Kelowna
Broad ranges. Size, glass type, coating, whether the unit is tempered, and access all move these.
| Work | Typical range |
|---|---|
| Measure and quote | often free, confirm |
| Sealed unit replacement, standard residential size | roughly $350 to $700 per unit |
| Sealed unit, large, tempered or specialty coated | roughly $700 to $1,600 per unit |
| Triple glazed unit | premium over double |
| Second storey or difficult access | premium for lift or scaffold |
| Full window replacement, retrofit into existing opening | roughly $900 to $2,500 per window |
| Full window replacement, full frame with exterior finishing | roughly $1,500 to $4,000 per window |
| Patio or sliding door glass unit | roughly $700 to $1,800 |
Volume matters. Doing six units in one visit is meaningfully cheaper per unit than doing one, because measuring, mobilization and the shop run are shared. If you have several failing, do them together.
Lead time also matters. Sealed units are usually made to order, so expect a wait between measure and install. Ask for the current lead time when you get the quote.
Warranty worth checking before you pay
Many sealed units carry a manufacturer warranty against seal failure, and the term is often long. Before you pay for replacement:
- Look for markings on the spacer bar between the panes, which often carry a manufacturer name and a date code.
- Check your home's build or renovation documents if the windows were installed by a previous owner.
- Ask the glass company to identify the unit. They see these every day and can often tell you the manufacturer from the spacer profile.
Warranties commonly cover the glass unit and not the labour, so even a successful claim usually still involves a bill. It is a smaller one.
Frequently asked questions
Is a foggy window an emergency?
No. It is a performance and appearance problem, not a weather tightness problem. Plan it rather than rush it.
Will it get worse?
Generally yes. Once the seal is open, moisture cycles in and out and mineral deposits accumulate. A unit caught early is more likely to defog cleanly if you go that route.
Does it really cost me on my energy bill?
It costs you some. Losing the gas fill reduces the unit's insulating value. On one window in a house it is small; on a whole south elevation it is noticeable, mostly as summer heat gain in this climate.
Can I replace the glass myself?
On some window types physically yes, but measuring a sealed unit correctly is exacting, the units are heavy and fragile, and an error means paying for a custom piece of glass twice.
My window is fogging on the outside surface in the morning. Is that failure?
No, that is dew on the exterior glass and it is usually a sign of a well insulating window. It clears as the day warms.
How long should new units last?
Ask the specific manufacturer's warranty term, and note that the south and west elevations of your house are a harder environment than the average.
A Kelowna option worth calling
*Disclosure: Glass Project Solutions Ltd, which serves the Kelowna market, is a business listed on the Okanagan Trade Directory. The description below comes from their own published information. They do not have a public Google star rating in our records, so ask for local references.*
Glass Project Solutions Ltd is a glass and glazing company serving homeowners, builders, renovation contractors, interior and commercial designers, architectural engineers and developers. The team handles both residential and commercial work, including glass railings in picket and topless styles, frameless shower enclosures and bathtub glass, mirrors, glass backsplashes, office glass partitions, wine rooms, smart glass and films, sunrooms and patio enclosures, storefront windows and doors, and curtainwall systems. They also offer window and glass repair and replacement. In the Okanagan they list service areas including Kelowna, West Kelowna, Vernon, Penticton, Summerland, Osoyoos and Lake Country. The company states it is fully licensed and insured with more than 25 years in the glass industry.
See their Okanagan Trade Directory listing or visit glassprojectsolutions.ca.
Before you pay for anything, walk the house and count how many units have gone. Doing them in one visit is the cheapest version of this job.