Blog
Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

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

If you see condensation on your window, don’t worry! It isn’t time to start looking for something wrong with 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. Instead, it means your windows are being efficient.

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

Do my new windows or doors create condensation?
Some homeowners connect the sight of condensation in the months after installing new windows with unnoticed problems during the installation process. Condensation on windows and doors is not produced by the window or door product. Rather, it comes because of high humidity levels in your home.

In reality, the presence of condensation more often than not is an outcome of the better energy efficiency of your new windows. Air with more humidity keeps 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. Due to the fact that glass surfaces are often the coldest part of the room, condensation can be seen on windows more frequently, in the indication of water droplets or frost on the roomside of the house’s window. As the air inside gets drier, or as the glass surface warms, condensation begins to lessen.

Numerous 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 a different one doesn’t. Air circulation, varying room temperatures, air register location, and the type and size of the window can all increase the chances of roomside condensation. Other influnences such as 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 occasionally see condensation on opposite sides of the window?
Your previous windows might have been drafty or didn’t feature the advanced, energy efficient elements of present-day windows. But, other home repairs, such as installing a new roof or siding, might also build a tighter seal against air infiltration in your house. Because of that, your home may keep more humidity making condensation more likely to be seen than before.

In the warmer seasons, this same phenomenon can be observed on the outside of your windows. Exterior condensation can appear because of high outdoor humidity, little or no wind, and a clear night sky. It establishes itself 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 house isn’t escaping 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 cutting back any bushes that might be obstructing windows. Setting the air conditioner a few degrees warmer can also help.

For roomside condensation, there are a number of factors that can determine the humidity in your home. 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 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–topping out at 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 way to escape.

Because of this better insulation, some windows can develop a strip of condensation that shows up all the way around the roomside of the window. Normally, this is created 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 instance 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 instance, condensation is a sign 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 hidden, potentially expensive problems to be found in your home.

igh indoor humidity can lead to structural damage and even upset 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 evolve into more serious concerns such as water stains on walls and ceilings if left unchecked.

In the same way, left unaddressed, condensation issues can cause window problems over time. Make sure to take reoccurring 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 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 and Doors in Annapolis a call or visit the showroom.

Back to Blog