Skip to Content
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 impact your heating bill by retaining more temperate air in your home while keeping the elements outside. However, you may start to find condensation gathering 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. In fact, 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 working well.

So, what is causing 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 lead to condensation?
Some homeowners pair the signs 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. Actually, it comes due to high humidity levels in your house.

As a matter of fact, the signs of condensation more often than not is a result of the better energy efficiency of your new windows. Air with increased humidity keeps water vapor until it comes into contact 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 room, condensation appears on windows first, in the presence 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 dissipate.

More than a few factors go into whether you might find 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, changing room temperatures, air register location, and the type and size of the window can all increase the likelihood 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 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 have the advanced, energy efficient elements of modern windows. Additionally, other home repairs, such as installing a new roof or siding, might also establish a tighter seal against air infiltration in your room. Due to that, your home may retain more humidity making condensation more likely to be seen than before.

In the summer months, this same phenomenon can be seen on the outside of your windows. Exterior condensation can gather because 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 house isn’t leaking due to increased energy efficiency, it’s more likely to see external condensation at these times.

You can manage exterior condensation by opening shades at night to warm up exterior glass and promote air circulation by cutting back any shrubbery that might be interfering with 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 house. Here are a couple of common culprits that can create roomside condensation:

Sources of humidity in your home 

The most common 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 bring moisture to the air in your home–up to four gallons or more per day in some homes. Add today’s energy efficient, well-insulated homes and you can start to get an idea why that humidity can often find no path to escape.

Because of this better insulation, some windows can build a strip of condensation that shows up all the way around the roomside of the window. Normally, 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 Ruin My Windows?
One place where condensation on windows should become an immediate issue, 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 must be replaced.

More likely 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 unseen, potentially costly problems to be found in your house.

High indoor humidity can lead to structural damage and even affect 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 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 alert to high humidity in your home, one that can easily be solved before it gets serious. 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 McComb Window & Door in Muncie a call or stop by the showroom.

Back to Blog