Skip to Content
Blog
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 expenses by keeping more temperate air in your house while keeping the elements outside. However, you may start to notice 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. 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 doing their job.

So, what is leading to the condensation on your windows? And, more importantly, what signs of condensation should raise alarms 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 created by the window or door product. Actually, it comes because of high humidity levels in your house.

As a matter of fact, the sight of condensation more often than not is an outcome of the improved 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. Due to the fact that glass surfaces are usually the coldest part of the home, condensation shows up on windows more frequently, in the presence of water droplets or frost on the roomside of the window. As the air inside becomes drier, or as the glass surface warms, condensation begins to lessen.

Numerous 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 a different one doesn’t. Air circulation, changing 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 determine what levels of humidity can be noticed 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 include the advanced, energy efficient components of present-day windows. Additionally, other home repairs, such as installing a new roof or siding, might also create a tighter seal against air infiltration in your room. As a result, your home may retain more humidity making condensation more frequentl than before.

In the warmer seasons, this same phenomenon can be observed 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 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 leaving 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 promote air circulation by trimming any shrubbery that might be blocking windows. Programming the air conditioner a few degrees warmer can also make a difference.

For roomside condensation, there are a number of factors that can determine the humidity in your room. Here are a few common culprits that can create roomside condensation:

Sources of humidity in your home 

The most commonly seen way roomside humidity increases is through everyday activity. 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–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 see why that humidity can often find no path to escape.

Because of this better insulation, some windows can develop a strip of condensation that forms all the way around the roomside of the window. Usually, this occurs when the center of the glass stays warmer than the glass closest to the edge. It isn’t a sign that the window is leaking air or not functioning correctly.

Can Roomside Condensation Ruin My Windows?
One instance 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 instance, condensation is a mark of seal failure and the insulating glass will need to be replaced.

More likely though, condensation on your windows doesn’t mean there is a defect with your windows. It serves as an alert to the possibility of other hidden, potentially pricey problems to be found in your home.

High 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 presence of condensation on glass is a good sign that humidity levels are too high. And while window condensation and musty odors might be seen as bothersome, they can develop into more severe concerns such as water stains on walls and ceilings if left alone.

In the same way, left unaddressed, condensation issues can mean window problems over time. Make sure to take chronic roomside condensation seriously. Think of it as an early alarm to high humidity in your home, one that can easily be resolved before it gets more severe. 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 doing their jobs properly, give Pella Windows & Doors - Victoria in Victoria a call or visit the showroom.

Back to Blog