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

If you notice condensation on your window, don’t worry! It isn’t time to start investigating 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 leading to the condensation on your windows? And, more importantly, what signs 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 connect the signs of condensation in the months after installing new windows with possible problems during the installation process. Condensation on windows and doors is not caused by the window or door product. Rather, it comes because of high humidity levels in your home.

As a matter of fact, the sight of condensation more often than not is a result of the increased energy efficiency of your new windows. Air with increased humidity retains 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 usually the coldest part of the house, condensation shows up on windows first, in the form of water droplets or frost on the roomside of your window. As the air inside becomes drier, or as the glass surface becomes warmer, condensation begins to lessen.

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, varying room temperatures, air register location, and the type and size of the window can all influence the likelihood 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 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 feature the advanced, energy efficient elements of modern windows. However, other home repairs, such as installing a new roof or siding, might also build a tighter seal against air infiltration in your room. Due to that, your home may keep more humidity making condensation more frequentl than before.

In the heat, this same phenomenon can be noticed 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 drops below the dew point of the outside air. Since the cooler air inside your home isn’t leaving due to increased energy efficiency, it’s more likely to see external condensation at these times.

You can address exterior condensation by opening shades at night to warm up exterior glass and improve air circulation by removing any plants that might be interfering with 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 home. Here are a couple of 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. Taking 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–up to four gallons or more per day in some homes. Factor in today’s energy efficient, well-insulated homes and you can start to see why that humidity can often find no path to escape.

As a result of this better insulation, some windows can build a strip of condensation that appears all the way around the roomside of the window. Normally, this happens 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 Hurt My Windows?
One place 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 situation, condensation is a sign 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 defect with your windows. It serves as a sign to the possibility of other unnoticed, potentially costly problems elsewhere in your home.

High indoor humidity can lead to structural damage and even upset your health. Because these effects frequently go unseen in the wall cavities, attics and crawl spaces, the visible sign 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 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 lead to window problems over time. Make sure to take chronic roomside condensation seriously. Think of it as an early alert to high humidity in your home, one that can easily be dealt with before it gets more severe. 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 in Roanoke a call or stop by the showroom.

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