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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 affect your heating bill by retaining more temperate air in your house while defending against the elements outside. However, you may start to see condensation settling on your windows and doors during colder months.

If you find 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. Rather, 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 raise alarms about your window’s strength? Here are the facts about window condensation:

Do my new windows or doors cause condensation?
Some homeowners pair 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 caused by the window or door product. Instead, it comes due to high humidity levels in your house.

In reality, the signs of condensation more often than not is a result of the increased 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. Since glass surfaces are usually the coldest part of the home, condensation shows up 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 becomes warmer, condensation begins to dissipate.

Many 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, changes in room temperatures, air register location, and the type and size of the window can all impact the likelihood of roomside condensation. Even the glass type, window coverings and screens and proximity to a water source can all play a role in what levels of humidity appear 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 technology of today’s windows. But, other home repairs, such as adding a new roof or siding, might also establish a tighter seal against air infiltration in your house. Due to that, your home may hold 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 form 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 room isn’t leaking due to increased energy efficiency, it’s more likely to see external condensation in these situations.

You can address exterior condensation by opening curtains at night to warm up exterior glass and promote air circulation by trimming any bushes that might be blocking windows. Programming the air conditioner a few degrees warmer can also improve the situation.

For roomside condensation, there are a few factors that can determine the humidity in your home. Here are some 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. Taking showers and baths, cooking and washing dishes, doing laundry, even the dog’s water bowl can all add 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 path to escape.

Due to this better insulation, some windows can build a strip of condensation that shows up all the way around the roomside of the window. Usually, this occurs when the center of the glass stays warmer than the glass closest to the edge. It isn’t an indication 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 issue, however, is if condensation is seen 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.

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 elsewhere in your home.

igh 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 presence 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 nuisances, they can grow 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 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 comfortable and maintaining your windows. If you have any questions about condensation and whether your windows and doors are resisting condensation effectively, give Pella Windows and Doors in Lethbridge a call or visit the showroom.

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