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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 house while keeping the elements outside. However, you may start to see condensation appearing on your windows and doors during colder months.

If you find condensation on your window, don’t stress! It isn’t time to start looking for something wrong with 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 being efficient.

So, what is leading to the condensation on your windows? And, more importantly, what types of condensation should make you concerned about your window’s strength? Here are the facts about window condensation:

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

As it turns out, the sight of condensation more often than not is a result of the better energy efficiency of your new windows. Air with high 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 room, condensation can be seen on windows initially, in the presence of water droplets or frost on the roomside of the house’s window. As the air inside gets drier, or as the glass surface becomes warmer, condensation begins to lessen.

Many factors go into whether you might find 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 impact the presence 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 appear 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 have the advanced, energy efficient technology of modern windows. Additionally, other home repairs, such as installing a new roof or siding, might also establish a tighter seal against air infiltration in your house. Because of that, your home may retain more humidity making condensation more likely to happen than before.

In the heat, this same phenomenon can be seen on the outside of your windows. Exterior condensation can form 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 is cooled below the dew point of the outside air. Since the cooler air inside your room isn’t escaping due to increased energy efficiency, there’s a greater chance to see external condensation at times like these.

You can address exterior condensation by opening window coverings at night to warm up exterior glass and increase air circulation by cutting back any shrubbery that might be obstructing windows. Adjusting 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 home. Here are a couple of common culprits that can cause roomside condensation:

Sources of humidity in your home 

The most common way roomside humidity increases is through everyday living. Heat and moisture from 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–topping out at four gallons or more per day in some homes. Factor in today’s energy efficient, well-insulated homes and you can start to understand 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 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 appearing between the two sealed panes of insulating glass in multi-pane windows. In this instance, condensation is a mark of seal failure and the insulating glass must 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 hidden, potentially pricey problems in other areas in your room.

igh indoor humidity can lead to structural damage and even impact 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 clue that humidity levels are too high. And while window condensation and musty odors might be seen as bothersome, 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 mean window problems over time. Make sure to take chronic roomside condensation seriously. Think of it as an early warning to high humidity in your house, one that can easily be resolved 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 effectively, give Pella Windows and Doors in Washington DC a call or stop by the showroom.

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