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

If you notice condensation on your window, don’t worry! 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. Just the opposite, it means your windows are being efficient.

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

Do my new windows or doors lead to 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 created by the window or door product. Actually, it comes due to high humidity levels in your room.

In reality, the sight of condensation more often than not is a result of the better energy efficiency of your new windows. Air with increased 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 often the coldest part of the home, condensation appears on windows first, in the presence of water droplets or frost on the roomside of the house’s window. As the air inside gets drier, or as the glass surface becomes warmer, condensation begins to dissipate.

Many 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 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. Even the 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 may have been drafty or didn’t have the advanced, energy efficient technology of present-day windows. But, other home repairs, such as building a new roof or siding, might also create a tighter seal against air infiltration in your home. As a result, your home may keep more humidity making condensation more likely to happen than before.

In the warmer seasons, this same phenomenon can be observed on the outside of your windows. Exterior condensation can form because of high outdoor humidity, little or no wind, and a clear night sky. It forms 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 leaving due to increased energy efficiency, it’s more likely to see external condensation in these situations.

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

For roomside condensation, there are a group of factors that can impact the humidity in your room. Here are a couple of common culprits that can create roomside condensation:

Sources of humidity in your home 

The most common 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–up to 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 way to escape.

As a result of this better insulation, some windows can have a strip of condensation that forms all the way around the roomside of the window. Normally, this is created 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 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 case, 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 a sign to the possibility of other unseen, potentially expensive problems elsewhere in your home.

igh indoor humidity can eventually cause structural damage and even affect your health. Because these effects frequently go unnoticed in the wall cavities, attics and crawl spaces, the visible indication 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 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 continual roomside condensation seriously. Think of it as an early warning to high humidity in your room, one that can easily be resolved 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 resisting condensation properly, give Pella Windows and Doors in Boone a call or stop by the showroom.

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