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What Causes Cloudy Windows? Foggy Window Repair Options

If your home was built—or your windows replaced—after 1990, chances are that the glass in your window frames is double- or triple-pane. This insulated glass is far more energy-efficient than its single-pane predecessor, making it the preferred option for all builders and installers. If you are in need of affordable foggy window repair options, keep reading!

Especially with the hot summers we get in Raleigh, having an extra layer of protection to keep cool air in and hot air out makes a major dent in your heating and cooling bills. But what if you’ve noticed fog and condensation forming on the inside of your window where you can’t wipe it away? If foggy windows are blocking your light and visibility, our custom glass company in Raleigh is breaking down why this insulated glass forms condensation, what it means for your energy efficiency, and how to restore clarity to your windows. 

How Does Insulated Glass Work?

Double- and triple-pane glass, also known as thermal windows, or insulated glass units (IGUs), can be as simple as two or three panes of glass that have been sealed together within your frame and can’t be separated. In these simpler constructions, the space between the panes is filled only with air. While these prove more energy-efficient than a single-pane window, the molecules in the air still allow for a fairly easy transfer of thermal energy. That means they might not provide the most effective prevention of heat loss.

The best option for energy efficiency is double- or triple-pane insulated glass in which a heavy gas like argon is sealed within the panes or specialized thermal coatings on the glass. The molecules in this gas move slower when they come into contact with thermal energy, minimizing its transfer so you won’t experience hot August air radiating into your home through your windows (or cold January air, for that matter). 

A foggy window can be fixed by affordable foggy window repair options

Why Does Fog Get Between Double Pane Windows?

Over time, the sealed edges of the glass can wear out or fail and if there is inert gas between the panes, it will eventually filter out. Sunlight, water, water vapor, and even temperature and barometric pressure can cause these seals to break down. The average life expectancy of the insulated glass unit (IGU) is around 15 years, though the factors listed can speed up or slow down that time frame.

Broken Seals

Broken seals are the number one culprit when it comes to foggy windows. Once the seals fail—which will happen eventually to all windows with these seals—moisture leaches into the space between the glass and temperature shifts, causing condensation to form. 

While the foggy windows may evaporate and clear up from day to day, if left untreated, calcium in condensation can etch the glass and leave a permanent hazy appearance on your windows.

Excess Moisture 

Floods, rainstorms, and even extreme humidity can contribute to the quicker dissolution of the window seals and therefore lead to foggy windows. 

To mitigate the moisture your seals are exposed to, try to keep the humidity lower in your home whenever possible. 

Temperature Outside

The more dramatic the temperature change in your area, the worse the condensation on your windows will be. In the summer, you may not notice this condensation as often, if at all, as the moisture is unlikely to condense. Once the weather cools, though, you’ll probably notice foggy windows as moist air on cold panels condenses into water. 


Similar to the effects of extreme temperatures, very warm weather and accompanying direct sunlight can speed up the deterioration of the window seals.

As air warms inside a window pane, it may stretch the seals themselves, causing them to wear. Direct sunlight increases these temperatures, which leads to a quicker breakdown. 

Barometric Pressure  

Changes in barometric pressure, also known as atmospheric pressure, can cause an increase in the intensity of weather phenomena like hurricanes and tornado winds. This can then create more pressure on a window seal, or affect its suction. Prolonged or repeated changes can wear on the seal and cause it to break. 

It’s also important to note that foggy windows are more than an inconvenience. Because there is a build-up of moisture between the panes of glass, it can lead to mold and water damage.

Is Foggy Window Repair Necessary for Energy Efficiency?

Though it is a good idea to prioritize foggy window repair if you are dealing with an issue in your home, it is not always in need of immediate or emergency repair. The fact is that foggy windows, though they can lead to mold and water damage when left untreated for too long, are largely an aesthetic issue. The breaking down of the seal will impact the gas in between the panes and therefore your energy efficiency, but not so much that you see a huge difference in your energy bill. 

If need be, you can wait a bit to replace or defog your windows without significant losses or damage being incurred. 

Solutions for Foggy Windows

For a long time, the only way to fix an IGU was to replace the entire window  – even the wooden or vinyl frame. Today, professional glass installers have a few other tricks up their sleeve when it comes to foggy window repair. 

Replacing the Entire Window

If you’re dealing with foggy windows that you want to be fixed ASAP, and you are also looking to update your home’s appearance, you might take this opportunity to replace the entire window—frame and all. 

This is a good option if you are working with a larger budget, as it is the most expensive route. It’s also helpful if you’re living in a much older house where the long-term cost and aesthetic benefits of new energy-efficient windows and brand-new frames might be worth the bigger undertaking. 

Replacing the IGU Panels Only 

Replacing only the glass panels of your windows will be less expensive than replacing the entire unit, and solve the problem of foggy windows. 

If you are only in need of foggy window repair for one or two windows, you’ll likely easily find a contractor to do this work at a lower cost than an entire window replacement throughout your home. 

Keep in mind that when you replace your window glass entirely, you will be protected by a warranty against damage or required repair for a certain amount of time post-installation. 

Window Defogging

There are window defogging kits available for a DIY repair, and you can also have your windows defogged by professionals like those at Glass Solutions. 

Basically, during the process tiny holes are drilled in the glass to remove the moisture, then an anti-fog solution is applied between the panes of glass, and a liquid sealant is applied to the bottom of the glass. Once complete, another seal is installed where any holes were drilled.

While this provides a great cosmetic solution to the issue, clearing up visibility and restoring clarity, you will lose the window’s insulation benefits. This is because the inert gas in the IGUs will be released and air will fill the space instead.   

However, this is also the least expensive foggy window repair solution, and that upfront savings may be worth it until you can replace your windows further down the line. 

Contact Us for Foggy Window Repair

If you want your windows to let in light and block out heat and cold, let us help you with our foggy window repair services. Our experienced team of glass experts is able to quickly install new insulated window glass so you can keep your energy efficient without having to replace an entire window. 

We serve Raleigh, Cary, Garner, Apex, Wake Forest, and surrounding areas. To get a free estimate or to schedule service, reach out to us today at  919-772-1007 or fill out our contact form below!