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Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

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

If you see condensation on your window, don’t worry! It isn’t time to start diagnosing your window. The fact is, condensation on the inside of your windows—known as roomside condensation—isn’t a sign of a defective window at all. Rather, it means your windows are working well.

So, what is leading to the condensation on your windows? And, more importantly, what types of condensation should make you concerned about your window’s strength? Here are the facts about window condensation:

Do my new windows or doors lead to condensation?
Some homeowners associate the signs of condensation in the months after installing new windows with unnoticed problems during the installation process. Condensation on windows and doors is not created by the window or door product. Actually, it comes as a result of high humidity levels in your room.

As a matter of fact, the signs of condensation more often than not is an indication of the increased energy efficiency of your new windows. Air with more humidity holds water vapor until it touches a surface temperature less than or equal to the dew point—the temperature at which air becomes saturated and produces dew. Since glass surfaces are often the coldest part of the home, condensation can be seen on windows more frequently, in the form of water droplets or frost on the roomside of your window. As the air inside becomes drier, or as the glass surface becomes warmer, condensation begins to lessen.

Many factors go into whether you might notice condensation on your windows. You might even notice 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 influence the likelihood of roomside condensation. Even the glass type, window coverings and screens and proximity to a water source can all have an impact on what levels of humidity appear around a window.

Why do I at times see condensation on opposite sides of the window?
Your previous windows might have been drafty or didn’t feature the advanced, energy efficient elements of today’s windows. But, other home repairs, such as adding a new roof or siding, might also establish a tighter seal against air infiltration in your home. As a result, your home may keep more humidity making condensation more likely to be seen than before.

In the warmer seasons, this same phenomenon can be seen on the outside of your windows. Exterior condensation can appear because of high outdoor humidity, little or no wind, and a clear night sky. It forms in the same way as roomside condensation, when the temperature of the glass drops below the dew point of the outside air. Since the cooler air inside your room isn’t leaving due to increased energy efficiency, there’s a higher possibility to see external condensation in these situations.

You can address exterior condensation by opening window coverings at night to warm up exterior glass and increase air circulation by removing any shrubbery that might be blocking windows. Programming the air conditioner a few degrees warmer can also make a difference.

For roomside condensation, there are a group of factors that can determine the humidity in your home. Here are a few common culprits that can lead to roomside condensation:

Sources of humidity in your home 

The most commonly seen way roomside humidity increases is through everyday home activities. Heat and moisture from showers and baths, cooking and washing dishes, doing laundry, even the dog’s water bowl can all add 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 understand why that humidity can often find no means of escape.

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

Can Roomside Condensation Hurt My Windows?
One place where condensation on windows should become an immediate warning, however, is if condensation is seen between the two sealed panes of insulating glass in multi-pane windows. In this case, condensation is a sign of seal failure and the insulating glass will need to 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 alert to the possibility of other unnoticed, potentially costly problems to be found in your home.

igh indoor humidity can lead to structural damage and even impact 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 clue that humidity levels are too high. And while window condensation and musty odors might be seen as nuisances, they can grow into more serious concerns such as water stains on walls and ceilings if left alone.

In the same way, left unaddressed, condensation issues can lead to window problems over time. Make sure to take chronic roomside condensation seriously. Think of it as an early alarm to high humidity in your room, one that can easily be dealt with before it gets more severe. Understanding condensation is just the beginning to keeping your home comfy and maintaining your windows. If you have any questions about condensation and whether your windows and doors are doing their jobs effectively, give Pella Windows and Doors in South Portland a call or stop by the showroom.

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