Blog
Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

It’s almost that weather where energy efficient windows can improve your heating expenses by keeping more temperate air in your room while defending against the elements outside. However, you may start to notice condensation settling on your windows and doors during colder months.

If you find condensation on your window, don’t stress! 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. Just the opposite, it means your windows are doing their job.

So, what is creating 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 cause condensation?
Some homeowners connect the sight of condensation in the months after installing new windows with potential problems during the installation process. Condensation on windows and doors is not caused by the window or door product. Rather, it comes because of high humidity levels in your home.

As it turns out, the signs of condensation more often than not is an indication of the better energy efficiency of your new windows. Air with increased humidity holds 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 house, condensation can be seen on windows first, in the form of water droplets or frost on the roomside of the house’s window. As the air inside grows drier, or as the glass surface becomes warmer, condensation begins to disappear.

More than a few 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 another in the same room doesn’t. Air circulation, changing room temperatures, air register location, and the type and size of the window can all increase 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 can be noticed 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 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. As a result, your home may hold more humidity making condensation more likely to happen than before.

In the warmer seasons, this same phenomenon can be seen on the outside of your windows. Exterior condensation can appear due to 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 drops 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 at times like these.

You can manage exterior condensation by opening window coverings at night to warm up exterior glass and promote air circulation by removing any shrubbery that might be interfering with windows. Adjusting the air conditioner a few degrees warmer can also improve the situation.

For roomside condensation, there are a group of factors that can influence the humidity in your house. Here are a few common culprits that can cause roomside condensation:

Sources of humidity in your home 

The most frequent way roomside humidity increases is through everyday living. Heat and moisture from showers and baths, cooking and washing dishes, doing laundry, even the dog’s water bowl can all bring 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.

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. 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 Hurt My Windows?
One place where condensation on windows should become an immediate concern, 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 will need to 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 unnoticed, potentially costly problems elsewhere in your room.

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 annoyances, 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 reoccurring roomside condensation seriously. Think of it as an early warning to high humidity in your house, 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 Edmonton a call or come into the showroom.

Back to Blog