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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 home while keeping the elements outside. However, you may start to find condensation appearing on your windows and doors during colder months.

If you see condensation on your window, don’t stress! It isn’t time to start diagnosing 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 causing the condensation on your windows? And, more importantly, what signs of condensation should make you concerned about your window’s strength? 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 possible problems during the installation process. Condensation on windows and doors is not caused by the window or door product. Actually, it comes due to high humidity levels in your house.

As it turns out, the presence of condensation more often than not is an indication of the increased energy efficiency of your new windows. Air with high humidity holds water vapor until it connects 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 often the coldest part of the house, condensation can be seen on windows more frequently, in the indication of water droplets or frost on the roomside of the house’s window. As the air inside becomes drier, or as the glass surface heats up, condensation begins to dissipate.

Many factors go into whether you might notice 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, changing room temperatures, air register location, and the type and size of the window can all influence the chances of roomside condensation. Other factors like glass type, window coverings and screens and proximity to a water source can all play a role in what levels of humidity appear around a window.

Why do I occasionally see condensation on opposite sides of the window?
Your previous windows might have been drafty or didn’t feature the advanced, energy efficient elements of today’s windows. However, other home repairs, such as adding a new roof or siding, might also create a tighter seal against air infiltration in your house. Because of that, your home may hold more humidity making condensation more likely to be seen than before.

In the heat, this same phenomenon can be seen 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 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 leaking due to increased energy efficiency, it’s more likely to see external condensation in these situations.

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

For roomside condensation, there are a group of factors that can determine the humidity in your home. Here are a couple of common culprits that can cause roomside condensation:

Sources of humidity in your home 

The most frequent 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. Include 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 have 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 a warning that the window is leaking air or not functioning correctly.

Can Roomside Condensation Damage My Windows?
One instance where condensation on windows should become an immediate issue, 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 must be replaced.

More often than not 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 house.

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 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 bothersome, they can develop into more serious concerns such as water stains on walls and ceilings if left unresolved.

In the same way, left unaddressed, condensation issues can lead to window problems over time. Make sure to take chronic roomside condensation seriously. Think of it as an early warning 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 comfortable and maintaining your windows. If you have any questions about condensation and whether your windows and doors are doing their jobs effectively, give Pella Windows and Doors in Jackson a call or visit the showroom.

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