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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 impact your heating costs by keeping more temperate air in your house while defending against the elements outside. However, you may start to find condensation settling on your windows and doors during colder months.

If you notice condensation on your window, don’t stress! 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. Instead, it means your windows are being efficient.

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

Do my new windows or doors create condensation?
Some homeowners associate the sight of condensation in the months after installing new windows with potential problems during the installation process. Condensation on windows and doors is not created by the window or door product. Rather, it comes as a result of high humidity levels in your house.

In reality, the presence of condensation more often than not is a result of the increased energy efficiency of your new windows. Air with high 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. Since glass surfaces are often the coldest part of the room, condensation appears on windows first, in the presence of water droplets or frost on the roomside of your window. As the air inside gets drier, or as the glass surface becomes warmer, condensation begins to lessen.

More than a few 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 a different one doesn’t. Air circulation, changes in room temperatures, air register location, and the type and size of the window can all influence 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 elements of modern windows. Additionally, other home repairs, such as building a new roof or siding, might also build a tighter seal against air infiltration in your home. Due to that, your home may hold 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 due to 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 home isn’t leaving due to increased energy efficiency, there’s a higher possibility to see external condensation at times like these.

You can manage exterior condensation by opening shades at night to warm up exterior glass and increase air circulation by removing any bushes that might be blocking windows. Programming the air conditioner a few degrees warmer can also improve the situation.

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

Sources of humidity in your home 

The most frequent 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 increase moisture to the air in your home–topping out at four gallons or more per day in some homes. Include 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 develop a strip of condensation that shows up all the way around the roomside of the window. Usually, 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 Ruin My Windows?
One instance 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 instance, condensation is a mark of seal failure and the insulating glass must be replaced.

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

igh indoor humidity can result in structural damage and even affect your health. Because these effects frequently go without notice 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 annoyances, they can develop 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 room, one that can easily be dealt with before it gets serious. 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 doing their jobs as they should, give Pella Windows and Doors in Boise a call or visit the showroom.

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