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Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

It’s almost that time of year where energy efficient windows can improve your heating expenses by keeping more temperate air in your house while resisting the elements outside. However, you may start to find condensation settling on your windows and doors during colder months.

If you see condensation on your window, don’t worry! 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 doing their job.

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

Do my new windows or doors cause condensation?
Some homeowners connect 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 created by the window or door product. Actually, it comes as a result of high humidity levels in your room.

In reality, the signs of condensation more often than not is an outcome of the increased 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 room, condensation shows up on windows initially, in the form of water droplets or frost on the roomside of the 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 find 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 increase 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 can be noticed around a window.

Why do I sometimes see condensation on opposite sides of the window?
Your previous windows might have been drafty or didn’t feature the advanced, energy efficient technology of modern windows. But, other home repairs, such as adding a new roof or siding, might also build a tighter seal against air infiltration in your room. Due to that, your home may keep more humidity making condensation more frequentl than before.

In the heat, this same phenomenon can be seen on the outside of your windows. Exterior condensation can gather as a result 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 cools below the dew point of the outside air. Since the cooler air inside your room isn’t escaping due to increased energy efficiency, there’s a greater chance to see external condensation at these times.

You can address exterior condensation by opening curtains at night to warm up exterior glass and improve air circulation by trimming any bushes that might be obstructing windows. Programming the air conditioner a few degrees warmer can also improve the situation.

For roomside condensation, there are a number of 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 add 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 get an idea 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. Usually, this happens 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 Ruin My Windows?
One instance where condensation on windows should become an immediate concern, however, is if condensation is appearing between the two sealed panes of insulating glass in multi-pane windows. In this situation, condensation is a mark of seal failure and the insulating glass will need to be replaced.

More likely 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 pricey problems elsewhere in your home.

igh indoor humidity can lead to structural damage and even affect 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 signal 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 home, one that can easily be resolved before it gets worse. 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 doing their jobs properly, give Pella Windows and Doors in Des Moines a call or visit the showroom.

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