Blog
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 costs by keeping more temperate air in your room while keeping the elements outside. However, you may start to find condensation appearing on your windows and doors during colder months.

If you find condensation on your window, don’t panic! 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. Instead, it means your windows are being efficient.

So, what is leading to the condensation on your windows? And, more importantly, what kind of condensation should make you concerned about your window’s stability? Here are the facts about window condensation:

Do my new windows or doors cause condensation?
Some homeowners connect the signs 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. Instead, it comes as a result of high humidity levels in your room.

In reality, the signs of condensation more often than not is an indication of the better energy efficiency of your new windows. Air with high humidity keeps 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 most likely the coldest part of the house, condensation appears on windows more frequently, in the indication of water droplets or frost on the roomside of your window. As the air inside grows drier, or as the glass surface heats up, condensation begins to disappear.

More than a few factors go into whether you might see condensation on your windows. You might even find that a window in one part of your room has roomside condensation while one on the other side doesn’t. Air circulation, changes in room temperatures, air register location, and the type and size of the window can all influence the presence 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 sometimes see condensation on opposite sides of the window?
Your previous windows could have been drafty or didn’t feature the advanced, energy efficient technology of modern windows. However, other home repairs, such as building a new roof or siding, might also build a tighter seal against air infiltration in your house. As a result, your home may keep more humidity making condensation more likely to be seen than before.

In the warmer seasons, this same phenomenon can be noticed on the outside of your windows. Exterior condensation can gather due to 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 is cooled below the dew point of the outside air. Since the cooler air inside your room isn’t leaving due to increased energy efficiency, there’s a greater chance to see external condensation at these times.

You can deal with exterior condensation by opening window coverings at night to warm up exterior glass and promote air circulation by trimming any plants that might be obstructing windows. Adjusting the air conditioner a few degrees warmer can also make a difference.

For roomside condensation, there are a few factors that can determine the humidity in your room. Here are a few 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 activity. 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–as much as four gallons or more per day in some homes. Factor in today’s energy efficient, well-insulated homes and you can start to understand why that humidity can often find no path to escape.

As a result of this better insulation, some windows can build a strip of condensation that shows up all the way around the roomside of the window. Most often, 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 Ruin My Windows?
One area 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 mark of seal failure and the insulating glass should be replaced.

Most often though, condensation on your windows doesn’t mean there is a concern with your windows. It serves as an alert to the possibility of other unseen, potentially pricey problems in other areas in your home.

igh indoor humidity can lead to structural damage and even upset 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 evolve 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 alarm to high humidity in your room, one that can easily be dealt with before it gets worse. Understanding condensation is just the beginning to keeping your home cozy 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 Danville a call or come into the showroom.

Back to Blog