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Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

It’s almost that season where energy efficient windows can improve your heating bill by retaining more temperate air in your room while resisting the elements outside. However, you may start to find condensation appearing on your windows and doors during colder months.

If you notice condensation on your window, don’t panic! It isn’t time to start investigating 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 kind of condensation should cause concern about your window’s health? 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 potential problems during the installation process. Condensation on windows and doors is not created by the window or door product. Rather, it comes due to high humidity levels in your house.

As a matter of fact, the presence of condensation more often than not is an outcome of the improved energy efficiency of your new windows. Air with more 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. Due to the fact that glass surfaces are most likely the coldest part of the home, condensation appears on windows initially, in the form of water droplets or frost on the roomside of the window. As the air inside becomes 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 one on the other side doesn’t. Air circulation, changing room temperatures, air register location, and the type and size of the window can all impact 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 appear around a window.

Why do I at times see condensation on opposite sides of the window?
Your previous windows may have been drafty or didn’t have the advanced, energy efficient elements of present-day windows. However, other home repairs, such as installing 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 seen on the outside of your windows. Exterior condensation can gather 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 room isn’t leaking due to increased energy efficiency, there’s a greater chance to see external condensation at times like these.

You can manage exterior condensation by opening shades at night to warm up exterior glass and promote air circulation by removing any shrubbery that might be obstructing windows. Setting the air conditioner a few degrees warmer can also make a difference.

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

Sources of humidity in your home 

The most common way roomside humidity increases is through everyday living. Running 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–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 understand why that humidity can often find no path to escape.

Due to this better insulation, some windows can build a strip of condensation that shows up all the way around the roomside of the window. Usually, 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 Damage My Windows?
One place where condensation on windows should become an immediate concern, however, is if condensation is noticed 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 defect with your windows. It serves as an indicator to the possibility of other hidden, potentially pricey problems in other areas in your home.

igh indoor humidity can eventually cause structural damage and even upset your health. Because these effects frequently go without notice in the wall cavities, attics and crawl spaces, the visible indication 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 severe concerns such as water stains on walls and ceilings if left unchecked.

In the same way, left unaddressed, condensation issues can cause window problems over time. Make sure to take reoccurring roomside condensation seriously. Think of it as an early alert to high humidity in your room, one that can easily be resolved before it gets more severe. 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 doing their jobs as they should, give Pella Windows and Doors in Calgary a call or stop by the showroom.

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