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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 expenses by holding more temperate air in your room while keeping the elements outside. However, you may start to see condensation gathering on your windows and doors during colder months.

If you find 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 working well.

So, what is causing the condensation on your windows? And, more importantly, what signs of condensation should make you concerned about your window’s health? Here are the facts about window condensation:

Do my new windows or doors create condensation?
Some homeowners connect 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 produced by the window or door product. Rather, it comes as a result of high humidity levels in your house.

In reality, the presence of condensation more often than not is an indication of the better energy efficiency of your new windows. Air with high humidity retains 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. Due to the fact that glass surfaces are usually the coldest part of the home, condensation appears on windows first, in the indication of water droplets or frost on the roomside of your window. As the air inside gets drier, or as the glass surface warms, condensation begins to disappear.

More than a few factors go into whether you might see 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 influence the chances of roomside condensation. Even the glass type, window coverings and screens and proximity to a water source can all have an impact on 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 may have been drafty or didn’t have the advanced, energy efficient elements of present-day windows. But, other home repairs, such as building a new roof or siding, might also create a tighter seal against air infiltration in your room. Because of that, your home may keep 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 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 drops below the dew point of the outside air. Since the cooler air inside your room isn’t leaving due to increased energy efficiency, there’s a greater chance to see external condensation in these situations.

You can manage exterior condensation by opening curtains at night to warm up exterior glass and improve air circulation by cutting back any bushes that might be interfering with windows. Adjusting the air conditioner a few degrees warmer can also help.

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

Sources of humidity in your home 

The most common way roomside humidity increases is through everyday home activities. 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–up to four gallons or more per day in some homes. Add today’s energy efficient, well-insulated homes and you can start to understand why that humidity can often find no way 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 happens 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 Damage 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 instance, condensation is a mark of seal failure and the insulating glass should be replaced.

Most often 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 in other areas in your room.

igh indoor humidity can lead to structural damage and even affect your health. Because these effects frequently go unseen 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 grow into more immediate concerns such as water stains on walls and ceilings if left alone.

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 alarm to high humidity in your room, 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 resisting condensation as they should, give Pella Windows and Doors in Rochester a call or stop by the showroom.

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