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

If you see condensation on your window, don’t worry! It isn’t time to start investigating 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. Just the opposite, it means your windows are doing their job.

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

Do my new windows or doors create condensation?
Some homeowners connect the presence of condensation in the months after installing new windows with unnoticed problems during the installation process. Condensation on windows and doors is not caused by the window or door product. Actually, it comes due to high humidity levels in your room.

As it turns out, the sight of condensation more often than not is a result of the improved 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. Since glass surfaces are often the coldest part of the home, condensation appears on windows first, in the indication of water droplets or frost on the roomside of your window. As the air inside gets drier, or as the glass surface heats up, condensation begins to disappear.

Numerous factors go into whether you might notice condensation on your windows. You might even discover 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 increase the chances 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 are 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 technology of present-day windows. But, other home repairs, such as building a new roof or siding, might also establish a tighter seal against air infiltration in your house. Due to that, your home may retain 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 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 window coverings at night to warm up exterior glass and improve air circulation by trimming any shrubbery that might be interfering with windows. Setting the air conditioner a few degrees warmer can also help.

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

Sources of humidity in your home 

The most common way roomside humidity increases is through everyday activity. 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–as much as 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 way to escape.

Due to this better insulation, some windows can develop a strip of condensation that forms 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 area where condensation on windows should become an immediate issue, however, is if condensation is appearing 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 likely 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 hidden, potentially costly problems in other areas in your house.

igh indoor humidity can result in 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 signal that humidity levels are too high. And while window condensation and musty odors might be seen as annoyances, they can grow into more severe concerns such as water stains on walls and ceilings if left alone.

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 alert to high humidity in your home, one that can easily be dealt with before it gets worse. Understanding condensation is just the beginning to keeping your home comfy and maintaining your windows. If you have any questions about condensation and whether your windows and doors are resisting condensation as they should, give Pella Windows and Doors in Denver a call or come into the showroom.

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