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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 costs by retaining more temperate air in your house while keeping the elements outside. However, you may start to notice condensation gathering 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. As a matter of 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 doing their job.

So, what is creating 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 signs of condensation in the months after installing new windows with unnoticed 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.

As a matter of fact, the presence of condensation more often than not is a result of the increased energy efficiency of your new windows. Air with increased humidity holds 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 often the coldest part of the house, 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.

Numerous factors go into whether you might find 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, changes in room temperatures, air register location, and the type and size of the window can all impact the presence of roomside condensation. Even the 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 may have been drafty or didn’t include the advanced, energy efficient elements of modern windows. Additionally, other home repairs, such as building a new roof or siding, might also create 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 warmer seasons, this same phenomenon can be observed on the outside of your windows. Exterior condensation can form 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 cools below the dew point of the outside air. Since the cooler air inside your house isn’t leaking due to increased energy efficiency, there’s a higher possibility to see external condensation at times like these.

You can address exterior condensation by opening window coverings at night to warm up exterior glass and improve air circulation by cutting back any shrubbery that might be obstructing windows. Programming the air conditioner a few degrees warmer can also help.

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

Sources of humidity in your home 

The most commonly seen way roomside humidity increases is through everyday activity. Running showers and baths, cooking and washing dishes, doing laundry, even the dog’s water bowl can all bring 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.

As a result of this better insulation, some windows can develop a strip of condensation that shows up 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 a warning that the window is leaking air or not functioning correctly.

Can Roomside Condensation Damage My Windows?
One place where condensation on windows should become an immediate warning, 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 will need to be replaced.

More likely though, condensation on your windows doesn’t mean there is a problem with your windows. It serves as a sign to the possibility of other hidden, potentially costly problems to be found in your house.

igh indoor humidity can lead to 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 sign that humidity levels are too high. And while window condensation and musty odors might be seen as annoyances, they can grow into more serious concerns such as water stains on walls and ceilings if left unresolved.

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 alarm to high humidity in your home, one that can easily be resolved 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 working effectively, give Pella Windows and Doors in Mt. Pleasant a call or stop by the showroom.

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