Blog
Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

It’s almost that weather where energy efficient windows can affect your heating bill by keeping more temperate air in your house while defending against the elements outside. However, you may start to see condensation appearing on your windows and doors during colder months.

If you find condensation on your window, don’t stress! It isn’t time to start diagnosing 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 working well.

So, what is leading to the condensation on your windows? And, more importantly, what signs of condensation should cause concern about your window’s health? Here are the facts about window condensation:

Do my new windows or doors lead to condensation?
Some homeowners associate the sight of condensation in the months after installing new windows with unnoticed problems during the installation process. Condensation on windows and doors is not produced by the window or door product. Instead, it comes as a result of high humidity levels in your room.

In reality, the presence of condensation more often than not is an indication of the increased energy efficiency of your new windows. Air with high humidity retains 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. Because glass surfaces are most likely the coldest part of the home, condensation shows up on windows initially, in the form of water droplets or frost on the roomside of your window. As the air inside grows drier, or as the glass surface becomes warmer, condensation begins to lessen.

Numerous 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 a different one doesn’t. Air circulation, varying room temperatures, air register location, and the type and size of the window can all impact the presence of roomside condensation. Other influnences such as glass type, window coverings and screens and proximity to a water source can all play a role in what levels of humidity are 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 elements of present-day windows. Additionally, other home repairs, such as adding a new roof or siding, might also build a tighter seal against air infiltration in your room. Because of that, your home may retain more humidity making condensation more frequentl than before.

In the summer months, 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 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 leaking due to increased energy efficiency, there’s a higher possibility to see external condensation at these times.

You can deal with exterior condensation by opening shades at night to warm up exterior glass and promote air circulation by cutting back any bushes that might be obstructing windows. Adjusting 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 few common culprits that can lead to roomside condensation:

Sources of humidity in your home 

The most frequent 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 add moisture to the air in your home–as much as four gallons or more per day in some homes. Include today’s energy efficient, well-insulated homes and you can start to see why that humidity can often find no way to escape.

Because of this better insulation, some windows can build a strip of condensation that appears all the way around the roomside of the window. Most often, 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 Ruin My Windows?
One area where condensation on windows should become an immediate warning, however, is if condensation is seen 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.

Most often though, condensation on your windows doesn’t mean there is a concern 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 result in structural damage and even upset your health. Because these effects frequently go without notice 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 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 reoccurring roomside condensation seriously. Think of it as an early alarm to high humidity in your house, one that can easily be resolved before it gets worse. 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 properly, give Pella Windows and Doors in Gaithersburg a call or stop by the showroom.

Back to Blog