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

If you find condensation on your window, don’t stress! It isn’t time to start investigating 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. Rather, it means your windows are doing their job.

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

Do my new windows or doors cause condensation?
Some homeowners associate the signs 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. Actually, it comes because of high humidity levels in your room.

In reality, the presence of condensation more often than not is an outcome of the better energy efficiency of your new windows. Air with high humidity keeps 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 most likely the coldest part of the room, condensation appears on windows initially, in the form of water droplets or frost on the roomside of your window. As the air inside gets drier, or as the glass surface heats up, condensation begins to dissipate.

More than a few factors go into whether you might see 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 impact the chances of roomside condensation. Other influnences such as glass type, window coverings and screens and proximity to a water source can all determine what levels of humidity appear 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 include the advanced, energy efficient components of present-day windows. Additionally, other home repairs, such as installing a new roof or siding, might also establish a tighter seal against air infiltration in your home. Due to that, your home may hold more humidity making condensation more likely to happen than before.

In the summer months, this same phenomenon can be seen on the outside of your windows. Exterior condensation can appear 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 home isn’t leaking due to increased energy efficiency, it’s more likely to see external condensation in these situations.

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

For roomside condensation, there are a number of factors that can influence 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 commonly seen way roomside humidity increases is through everyday home activities. Heat and moisture from 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 see why that humidity can often find no way to escape.

As a result of this better insulation, some windows can build a strip of condensation that forms all the way around the roomside of the window. Normally, this occurs 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 Hurt My Windows?
One place where condensation on windows should become an immediate issue, 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 costly problems in other areas in your house.

igh 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 indication 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 develop into more immediate concerns such as water stains on walls and ceilings if left alone.

In the same way, left unaddressed, condensation issues can lead to window problems over time. Make sure to take reoccurring roomside condensation seriously. Think of it as an early alarm 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 effectively, give Pella Windows and Doors in Bloomington a call or visit the showroom.

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