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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 bill by retaining more temperate air in your room while resisting the elements outside. However, you may start to notice condensation settling on your windows and doors during colder months.

If you notice condensation on your window, don’t panic! It isn’t time to start looking for something wrong with 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 working well.

So, what is causing the condensation on your windows? And, more importantly, what signs of condensation should cause concern about your window’s health? Here are the facts about window condensation:

Do my new windows or doors lead to condensation?
Some homeowners associate 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. Rather, it comes as a result of high humidity levels in your house.

As a matter of fact, the presence of condensation more often than not is an indication of the improved 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. Since glass surfaces are usually the coldest part of the room, condensation appears on windows first, in the form of water droplets or frost on the roomside of the window. As the air inside grows drier, or as the glass surface becomes warmer, condensation begins to dissipate.

Numerous 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 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 presence of roomside condensation. Other influnences such as 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 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 components of today’s windows. Additionally, other home repairs, such as building a new roof or siding, might also build a tighter seal against air infiltration in your room. As a result, 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 as a result 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 window coverings at night to warm up exterior glass and promote air circulation by removing any shrubbery that might be obstructing windows. Programming the air conditioner a few degrees warmer can also make a difference.

For roomside condensation, there are a few factors that can influence the humidity in your house. Here are a few common culprits that can cause roomside condensation:

Sources of humidity in your home 

The most frequent 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 increase 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 means of escape.

Due to this better insulation, some windows can build a strip of condensation that forms 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 an indication that the window is leaking air or not functioning correctly.

Can Roomside Condensation Hurt My Windows?
One area where condensation on windows should become an immediate warning, however, is if condensation is noticed 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 often than not though, condensation on your windows doesn’t mean there is a concern with your windows. It serves as an indicator to the possibility of other hidden, potentially expensive problems elsewhere in your room.

igh indoor humidity can lead to structural damage and even impact your health. Because these effects frequently go without notice in the wall cavities, attics and crawl spaces, the visible sign of condensation on glass is a good sign that humidity levels are too high. And while window condensation and musty odors might be seen as nuisances, 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 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 dealt with 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 resisting condensation as they should, give Pella Windows and Doors in Kingston a call or visit the showroom.

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