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

If you see condensation on your window, don’t panic! It isn’t time to start diagnosing your window. As a matter of 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 causing the condensation on your windows? And, more importantly, what signs of condensation should cause concern about your window’s strength? 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 created by the window or door product. Instead, it comes due to high humidity levels in your house.

As it turns out, the signs of condensation more often than not is a result of the better energy efficiency of your new windows. Air with more humidity retains 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. Because glass surfaces are often the coldest part of the room, condensation appears on windows initially, in the presence of water droplets or frost on the roomside of your window. As the air inside grows drier, or as the glass surface warms, condensation begins to dissipate.

More than a few factors go into whether you might find condensation on your windows. You might even notice that a window in one part of your room has roomside condensation while a different one doesn’t. Air circulation, changes in room temperatures, air register location, and the type and size of the window can all influence the likelihood 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 can be noticed around a window.

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

In the warmer seasons, this same phenomenon can be observed 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 establishes itself 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 home isn’t escaping due to increased energy efficiency, there’s a higher possibility to see external condensation in these situations.

You can deal with exterior condensation by opening shades at night to warm up exterior glass and promote air circulation by removing any shrubbery that might be interfering with windows. Adjusting the air conditioner a few degrees warmer can also help.

For roomside condensation, there are a few factors that can determine the humidity in your room. Here are a few common culprits that can lead to roomside condensation:

Sources of humidity in your home 

The most frequent 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 increase 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 means of escape.

Because of this better insulation, some windows can have a strip of condensation that appears all the way around the roomside of the window. Most often, this happens when the center of the glass stays warmer than the glass closest to the edge. It isn’t a sign 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 warning, however, is if condensation is appearing 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 must 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 unnoticed, potentially pricey problems elsewhere in your home.

igh indoor humidity can eventually cause structural damage and even affect 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 signal that humidity levels are too high. And while window condensation and musty odors might be seen as bothersome, 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 room, one that can easily be solved before it gets serious. 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 working as they should, give Pella Windows and Doors in Scottsdale a call or stop by the showroom.

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