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

If you notice condensation on your window, don’t panic! It isn’t time to start looking for something wrong with 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. Instead, it means your windows are working well.

So, what is creating the condensation on your windows? And, more importantly, what types of condensation should raise alarms about your window’s strength? Here are the facts about window condensation:

Do my new windows or doors cause 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 produced by the window or door product. Rather, it comes due to high humidity levels in your home.

In reality, the signs of condensation more often than not is a result of the better energy efficiency of your new windows. Air with more 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. Due to the fact that glass surfaces are often the coldest part of the home, condensation can be seen on windows initially, in the form of water droplets or frost on the roomside of the window. As the air inside becomes drier, or as the glass surface becomes warmer, condensation begins to dissipate.

Many factors go into whether you might see 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, changes in room temperatures, air register location, and the type and size of the window can all increase the likelihood of roomside condensation. Even the glass type, window coverings and screens and proximity to a water source can all play a role in what levels of humidity are around a window.

Why do I occasionally 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 present-day windows. Additionally, other home repairs, such as building a new roof or siding, might also establish a tighter seal against air infiltration in your home. As a result, your home may keep more humidity making condensation more frequentl than before.

In the summer months, this same phenomenon can be observed on the outside of your windows. Exterior condensation can gather due to 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 house isn’t leaving due to increased energy efficiency, it’s more likely to see external condensation in these situations.

You can address exterior condensation by opening window coverings at night to warm up exterior glass and increase air circulation by removing any bushes that might be obstructing windows. Adjusting the air conditioner a few degrees warmer can also make a difference.

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

As a result of this better insulation, some windows can have a strip of condensation that appears all the way around the roomside of the window. Usually, 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 issue, however, is if condensation is noticed 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 often than not though, condensation on your windows doesn’t mean there is a problem with your windows. It serves as an indicator to the possibility of other unseen, potentially expensive problems elsewhere in your home.

High indoor humidity can lead to structural damage and even affect your health. Because these effects frequently go unnoticed 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 bothersome, they can develop into more severe concerns such as water stains on walls and ceilings if left unchecked.

In the same way, left unaddressed, condensation issues can mean window problems over time. Make sure to take continual roomside condensation seriously. Think of it as an early alarm to high humidity in your house, 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 effectively, give Pella Windows and Doors Southwest in El Paso a call or come into the showroom.

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