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Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

It’s almost that time of year where energy efficient windows can improve your heating bill by keeping more temperate air in your room while keeping the elements outside. However, you may start to find condensation appearing on your windows and doors during colder months.

If you find condensation on your window, don’t stress! It isn’t time to start diagnosing your window. In fact, condensation on the inside of your windows—known as roomside condensation—isn’t a sign of a defective window at all. Just the opposite, it means your windows are working well.

So, what is causing the condensation on your windows? And, more importantly, what signs of condensation should make you concerned about your window’s stability? Here are the facts about window condensation:

Do my new windows or doors lead to condensation?
Some homeowners associate the sight of condensation in the months after installing new windows with possible problems during the installation process. Condensation on windows and doors is not produced by the window or door product. Actually, it comes due to high humidity levels in your house.

As a matter of fact, the sight of condensation more often than not is an outcome of the increased energy efficiency of your new windows. Air with more humidity keeps water vapor until it connects with a surface temperature less than or equal to the dew point—the temperature at which air becomes saturated and produces dew. Because glass surfaces are most likely the coldest part of the home, condensation appears on windows more frequently, in the presence of water droplets or frost on the roomside of your window. As the air inside grows drier, or as the glass surface heats up, condensation begins to disappear.

Many factors go into whether you might find condensation on your windows. You might even discover that a window in one part of your room has roomside condensation while one on the other side doesn’t. Air circulation, changing room temperatures, air register location, and the type and size of the window can all increase the presence of roomside condensation. Other factors like glass type, window coverings and screens and proximity to a water source can all play a role in what levels of humidity appear around a window.

Why do I occasionally see condensation on opposite sides of the window?
Your previous windows could have been drafty or didn’t include the advanced, energy efficient technology of modern windows. However, other home repairs, such as installing a new roof or siding, might also build a tighter seal against air infiltration in your home. Due to that, your home may keep more humidity making condensation more likely to be seen than before.

In the summer months, this same phenomenon can be observed on the outside of your windows. Exterior condensation can gather as a result of high outdoor humidity, little or no wind, and a clear night sky. It establishes itself in the same way as roomside condensation, when the temperature of the glass is cooled below the dew point of the outside air. Since the cooler air inside your house isn’t escaping due to increased energy efficiency, there’s a higher possibility to see external condensation in these situations.

You can deal with exterior condensation by opening window coverings at night to warm up exterior glass and promote air circulation by cutting back any shrubbery that might be blocking windows. Adjusting the air conditioner a few degrees warmer can also make a difference.

For roomside condensation, there are a few factors that can impact the humidity in your room. Here are a couple of common culprits that can create roomside condensation:

Sources of humidity in your home 

The most commonly seen way roomside humidity increases is through everyday home activities. Running showers and baths, cooking and washing dishes, doing laundry, even the dog’s water bowl can all increase moisture to the air in your home–as much as four gallons or more per day in some homes. Add today’s energy efficient, well-insulated homes and you can start to see why that humidity can often find no path to escape.

Because of this better insulation, some windows can develop a strip of condensation that forms all the way around the roomside of the window. Normally, this occurs when the center of the glass stays warmer than the glass closest to the edge. It isn’t a sign that the window is leaking air or not functioning correctly.

Can Roomside Condensation Hurt My Windows?
One instance where condensation on windows should become an immediate concern, however, is if condensation is appearing between the two sealed panes of insulating glass in multi-pane windows. In this case, condensation is a mark of seal failure and the insulating glass should be replaced.

More often than not though, condensation on your windows doesn’t mean there is a concern with your windows. It serves as an indicator to the possibility of other unseen, potentially pricey problems elsewhere in your home.

igh indoor humidity can eventually cause structural damage and even affect your health. Because these effects frequently go unseen in the wall cavities, attics and crawl spaces, the visible indication of condensation on glass is a good signal that humidity levels are too high. And while window condensation and musty odors might be seen as annoyances, they can grow into more immediate concerns such as water stains on walls and ceilings if left unchecked.

In the same way, left unaddressed, condensation issues can lead to window problems over time. Make sure to take reoccurring roomside condensation seriously. Think of it as an early warning to high humidity in your house, one that can easily be resolved before it gets worse. Understanding condensation is just the beginning to keeping your home cozy and maintaining your windows. If you have any questions about condensation and whether your windows and doors are working as they should, give Pella Windows and Doors in Minneapolis a call or stop by the showroom.

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