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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 improve your heating costs 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 worry! It isn’t time to start investigating your window. The fact is, 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 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 connect the presence 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. Instead, it comes because of high humidity levels in your house.

As a matter of fact, the sight of condensation more often than not is a result of the improved energy efficiency of your new windows. Air with high humidity holds 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 usually the coldest part of the home, condensation appears on windows first, in the form of water droplets or frost on the roomside of the house’s window. As the air inside gets drier, or as the glass surface heats up, condensation begins to disappear.

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 one on the other side doesn’t. Air circulation, varying room temperatures, air register location, and the type and size of the window can all impact the likelihood of roomside condensation. Other factors like glass type, window coverings and screens and proximity to a water source can all have an impact on what levels of humidity are around a window.

Why do I sometimes see condensation on opposite sides of the window?
Your previous windows may have been drafty or didn’t feature the advanced, energy efficient technology of today’s windows. But, other home repairs, such as adding a new roof or siding, might also establish a tighter seal against air infiltration in your room. Due to that, your home may hold 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 appear because of 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 drops below the dew point of the outside air. Since the cooler air inside your home isn’t leaving due to increased energy efficiency, it’s more likely to see external condensation at these times.

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

For roomside condensation, there are a group of 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 commonly seen 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. Include today’s energy efficient, well-insulated homes and you can start to get an idea why that humidity can often find no way to escape.

Because of this better insulation, some windows can have a strip of condensation that shows up all the way around the roomside of the window. Most often, this occurs 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 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 mark of seal failure and the insulating glass will need to be replaced.

Most often though, condensation on your windows doesn’t mean there is a problem with your windows. It serves as an indicator to the possibility of other hidden, potentially expensive problems in other areas in your room.

High indoor humidity can eventually cause 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 annoyances, they can evolve into more immediate 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 chronic roomside condensation seriously. Think of it as an early warning to high humidity in your house, one that can easily be solved before it gets more severe. 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 properly, give Pella Windows and Doors in Cape Cod a call or come into the showroom.

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