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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 impact your heating costs by holding more temperate air in your home while keeping the elements outside. However, you may start to notice condensation appearing on your windows and doors during colder months.

If you find condensation on your window, don’t panic! 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. Instead, it means your windows are working well.

So, what is leading to the condensation on your windows? And, more importantly, what types of condensation should raise alarms about your window’s health? 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. Instead, it comes because of high humidity levels in your room.

As it turns out, the signs of condensation more often than not is an indication of the better 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. Since glass surfaces are often the coldest part of the home, condensation shows up on windows more frequently, 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 warms, condensation begins to dissipate.

Numerous factors go into whether you might see 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 have an impact on what levels of humidity appear around a window.

Why do I sometimes see condensation on opposite sides of the window?
Your previous windows could have been drafty or didn’t have the advanced, energy efficient technology of today’s windows. But, other home repairs, such as installing a new roof or siding, might also create a tighter seal against air infiltration in your home. Because of that, your home may keep more humidity making condensation more likely to happen than before.

In the heat, this same phenomenon can be noticed 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 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 escaping due to increased energy efficiency, it’s more likely to see external condensation at these times.

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

For roomside condensation, there are a few factors that can determine the humidity in your house. Here are a couple of common culprits that can cause 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. Include today’s energy efficient, well-insulated homes and you can start to get an idea why that humidity can often find no means of escape.

Due to this better insulation, some windows can develop a strip of condensation that appears all the way around the roomside of the window. Normally, 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 instance where condensation on windows should become an immediate concern, however, is if condensation is noticed between the two sealed panes of insulating glass in multi-pane windows. In this situation, condensation is a result of seal failure and the insulating glass should be replaced.

Most often though, condensation on your windows doesn’t mean there is a concern with your windows. It serves as a sign to the possibility of other hidden, potentially pricey problems elsewhere in your home.

High indoor humidity can result in structural damage and even upset your health. Because these effects frequently go unnoticed in the wall cavities, attics and crawl spaces, the visible sign of condensation on glass is a good signal that humidity levels are too high. And while window condensation and musty odors might be seen as annoyances, they can evolve into more immediate 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 alert to high humidity in your home, one that can easily be solved before it gets serious. Understanding condensation is just the beginning to keeping your home comfortable and maintaining your windows. If you have any questions about condensation and whether your windows and doors are working as they should, give Pella Windows and Doors in Wilmington a call or stop by the showroom.

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