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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 impact your heating bill by keeping more temperate air in your home while defending against the elements outside. However, you may start to see 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 looking for something wrong with 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. Rather, it means your windows are doing their job.

So, what is causing 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 cause condensation?
Some homeowners connect 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. Actually, it comes as a result of high humidity levels in your home.

In reality, the sight of condensation more often than not is a result of the improved energy efficiency of your new windows. Air with increased humidity keeps 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. Because 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 the window. As the air inside grows drier, or as the glass surface warms, condensation begins to disappear.

Many factors go into whether you might notice condensation on your windows. You might even discover that a window in one part of your room has roomside condensation while another in the same room doesn’t. Air circulation, varying room temperatures, air register location, and the type and size of the window can all increase the likelihood of roomside condensation. Other factors like glass type, window coverings and screens and proximity to a water source can all determine what levels of humidity can be noticed around a window.

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

In the summer months, this same phenomenon can be noticed on the outside of your windows. Exterior condensation can gather because 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 cools below the dew point of the outside air. Since the cooler air inside your home isn’t leaving due to increased energy efficiency, there’s a higher possibility to see external condensation at times like these.

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

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

Sources of humidity in your home 

The most common way roomside humidity increases is through everyday living. Running 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. Factor in today’s energy efficient, well-insulated homes and you can start to understand why that humidity can often find no path to escape.

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

Can Roomside Condensation Ruin My Windows?
One instance 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 case, condensation is a mark of seal failure and the insulating glass must be replaced.

More likely 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 unnoticed, potentially costly problems elsewhere in your house.

igh indoor humidity can eventually cause 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 signal that humidity levels are too high. And while window condensation and musty odors might be seen as nuisances, 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 cause window problems over time. Make sure to take chronic roomside condensation seriously. Think of it as an early warning to high humidity in your room, one that can easily be resolved before it gets worse. 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 resisting condensation effectively, give Pella Windows and Doors in Eau Claire a call or come into the showroom.

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