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

If you notice condensation on your window, don’t stress! It isn’t time to start diagnosing 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 doing their job.

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 stability? Here are the facts about window condensation:

Do my new windows or doors lead to 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 caused by the window or door product. Instead, it comes due to high humidity levels in your home.

In reality, the presence of condensation more often than not is a result of the improved 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. Because glass surfaces are most likely the coldest part of the house, condensation appears on windows first, in the presence of water droplets or frost on the roomside of the window. As the air inside gets drier, or as the glass surface warms, condensation begins to disappear.

Many factors go into whether you might see condensation on your windows. You might even find that a window in one part of your room has roomside condensation while a different one doesn’t. Air circulation, varying 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 have an impact on what levels of humidity can be noticed around a window.

Why do I occasionally see condensation on opposite sides of the window?
Your previous windows might have been drafty or didn’t feature the advanced, energy efficient components of today’s 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. 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 observed 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 grows in the same way as roomside condensation, when the temperature of the glass cools below the dew point of the outside air. Since the cooler air inside your house isn’t escaping due to increased energy efficiency, it’s more likely to see external condensation in these situations.

You can manage exterior condensation by opening curtains at night to warm up exterior glass and improve air circulation by removing any plants that might be interfering with 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 room. 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. Taking showers and baths, cooking and washing dishes, doing laundry, even the dog’s water bowl can all increase moisture to the air in your home–topping out at 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 means of escape.

As a result of this better insulation, some windows can develop a strip of condensation that appears all the way around the roomside of the window. Normally, this is created 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 Hurt My Windows?
One place where condensation on windows should become an immediate warning, however, is if condensation is seen between the two sealed panes of insulating glass in multi-pane windows. In this instance, condensation is a result of seal failure and the insulating glass should 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 alert to the possibility of other hidden, potentially pricey problems in other areas in your house.

igh indoor humidity can lead to structural damage and even upset 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 clue that humidity levels are too high. And while window condensation and musty odors might be seen as bothersome, they can evolve into more serious concerns such as water stains on walls and ceilings if left unresolved.

In the same way, left unaddressed, condensation issues can lead to window problems over time. Make sure to take reoccurring roomside condensation seriously. Think of it as an early warning to high humidity in your room, one that can easily be solved before it gets worse. 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 Falls Church a call or stop by the showroom.

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