Blog
Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

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

If you notice condensation on your window, don’t panic! It isn’t time to start looking for something wrong with 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. Rather, it means your windows are doing their job.

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

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

As it turns out, the sight 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 most likely the coldest part of the room, condensation appears on windows initially, in the form of water droplets or frost on the roomside of your window. As the air inside becomes drier, or as the glass surface becomes warmer, condensation begins to lessen.

Many factors go into whether you might see condensation on your windows. You might even discover that a window in one part of your room has roomside condensation while a different one doesn’t. Air circulation, changes in 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 determine what levels of humidity can be noticed around a window.

Why do I occasionally 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 today’s windows. But, other home repairs, such as building a new roof or siding, might also build a tighter seal against air infiltration in your room. Because of that, your home may hold more humidity making condensation more likely to happen than before.

In the summer months, this same phenomenon can be seen 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 is cooled below the dew point of the outside air. Since the cooler air inside your home isn’t leaking 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 increase air circulation by trimming any bushes that might be blocking 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 impact the humidity in your house. Here are a couple of common culprits that can lead to roomside condensation:

Sources of humidity in your home 

The most common way roomside humidity increases is through everyday living. Running 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–up to four gallons or more per day in some homes. Include today’s energy efficient, well-insulated homes and you can start to get an idea why that humidity can often find no means of escape.

Due to this better insulation, some windows can develop a strip of condensation that forms all the way around the roomside of the window. Usually, this happens 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 Damage 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 situation, condensation is a result 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 problem with your windows. It serves as an alert to the possibility of other unseen, potentially expensive problems in other areas in your room.

igh indoor humidity can lead to structural damage and even impact your health. Because these effects frequently go unseen in the wall cavities, attics and crawl spaces, the visible presence 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 nuisances, they can develop into more serious concerns such as water stains on walls and ceilings if left unchecked.

In the same way, left unaddressed, condensation issues can lead to window problems over time. Make sure to take continual roomside condensation seriously. Think of it as an early alert to high humidity in your room, one that can easily be dealt with before it gets serious. 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 working effectively, give Pella Windows and Doors in Champaign a call or stop by the showroom.

Back to Blog
Live Chat
I can help with your window or door replacement questions.