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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 improve your heating expenses by retaining more temperate air in your room while keeping the elements outside. However, you may start to see condensation appearing on your windows and doors during colder months.

If you notice condensation on your window, don’t panic! 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 doing their job.

So, what is causing the condensation on your windows? And, more importantly, what types of condensation should cause concern about your window’s stability? Here are the facts about window condensation:

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

As it turns out, the sight of condensation more often than not is an outcome of the increased energy efficiency of your new windows. Air with more 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. Since glass surfaces are most likely the coldest part of the house, condensation can be seen on windows initially, in the form of water droplets or frost on the roomside of your window. As the air inside grows drier, or as the glass surface heats up, condensation begins to lessen.

Numerous factors go into whether you might notice condensation on your windows. You might even find 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. Other influnences such as 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 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 present-day windows. But, other home repairs, such as installing a new roof or siding, might also build a tighter seal against air infiltration in your house. Due to that, your home may retain more humidity making condensation more frequentl than before.

In the heat, 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 establishes itself 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 manage exterior condensation by opening curtains at night to warm up exterior glass and increase air circulation by trimming any bushes that might be interfering with windows. Programming 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 room. Here are some common culprits that can cause roomside condensation:

Sources of humidity in your home 

The most frequent way roomside humidity increases is through everyday living. 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–as much as four gallons or more per day in some homes. Include today’s energy efficient, well-insulated homes and you can start to get an idea 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 forms all the way around the roomside of the window. Most often, 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 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 case, condensation is a mark of seal failure and the insulating glass should 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 expensive problems elsewhere 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 presence 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 nuisances, they can grow into more immediate 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 continual 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 worse. 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 Concord a call or visit the showroom.

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