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Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

It’s almost that weather where energy efficient windows can affect your heating expenses by holding more temperate air in your house while resisting the elements outside. However, you may start to find condensation settling on your windows and doors during colder months.

If you find condensation on your window, don’t panic! It isn’t time to start investigating 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 being efficient.

So, what is leading to the condensation on your windows? And, more importantly, what signs of condensation should raise alarms about your window’s stability? Here are the facts about window condensation:

Do my new windows or doors cause condensation?
Some homeowners pair the presence of condensation in the months after installing new windows with potential problems during the installation process. Condensation on windows and doors is not caused by the window or door product. Rather, it comes due to high humidity levels in your home.

In reality, the sight of condensation more often than not is an outcome of the better energy efficiency of your new windows. Air with high humidity retains water vapor until it comes into contact 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 usually the coldest part of the room, condensation appears on windows initially, 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 becomes warmer, condensation begins to dissipate.

More than a few factors go into whether you might see condensation on your windows. You might even notice that a window in one part of your room has roomside condensation while another in the same room doesn’t. Air circulation, changing room temperatures, air register location, and the type and size of the window can all impact the chances of roomside condensation. Other factors like glass type, window coverings and screens and proximity to a water source can all have an impact on what levels of humidity are around a window.

Why do I sometimes see condensation on opposite sides of the window?
Your previous windows might have been drafty or didn’t have the advanced, energy efficient components of modern windows. However, other home repairs, such as building a new roof or siding, might also create a tighter seal against air infiltration in your home. Because of 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 appear as a result of high outdoor humidity, little or no wind, and a clear night sky. It grows 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 leaking due to increased energy efficiency, there’s a higher possibility to see external condensation at these times.

You can address exterior condensation by opening curtains at night to warm up exterior glass and improve air circulation by cutting back any bushes that might be interfering with windows. Adjusting the air conditioner a few degrees warmer can also help.

For roomside condensation, there are a number of factors that can impact the humidity in your home. Here are a couple of common culprits that can cause roomside condensation:

Sources of humidity in your home 

The most frequent way roomside humidity increases is through everyday home activities. Taking 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–up to 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 way 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 Damage My Windows?
One area where condensation on windows should become an immediate concern, however, is if condensation is seen between the two sealed panes of insulating glass in multi-pane windows. In this instance, condensation is a sign of seal failure and the insulating glass must be replaced.

Most often though, condensation on your windows doesn’t mean there is a concern with your windows. It serves as a sign to the possibility of other hidden, potentially costly problems to be found in your home.

igh indoor humidity can result in structural damage and even upset your health. Because these effects frequently go without notice in the wall cavities, attics and crawl spaces, the visible sign 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 evolve 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 continual roomside condensation seriously. Think of it as an early alarm to high humidity in your room, one that can easily be resolved before it gets serious. 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 working properly, give Pella Windows and Doors in Asheville a call or stop by the showroom.

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