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Window Condensation: Understanding What It Means

Window Condensation: Understanding What It Means

It’s almost that season where energy efficient windows can impact your heating bill by retaining more temperate air in your house while keeping the elements outside. However, you may start to notice 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 investigating your window. As a matter of 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 doing their job.

So, what is creating the condensation on your windows? And, more importantly, what types of condensation should make you concerned about your window’s health? 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 created by the window or door product. Instead, it comes because of high humidity levels in your home.

As it turns out, the presence of condensation more often than not is an outcome 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 usually 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 window. As the air inside grows drier, or as the glass surface becomes warmer, condensation begins to lessen.

More than a few factors go into whether you might notice 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 likelihood of roomside condensation. Other factors like 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 sometimes see condensation on opposite sides of the window?
Your previous windows could have been drafty or didn’t feature the advanced, energy efficient components of today’s windows. However, other home repairs, such as building a new roof or siding, might also build a tighter seal against air infiltration in your house. Because of that, your home may hold more humidity making condensation more likely to be seen than before.

In the warmer seasons, this same phenomenon can be noticed 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 establishes itself 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 leaving due to increased energy efficiency, there’s a higher possibility to see external condensation at times like these.

You can manage exterior condensation by opening curtains at night to warm up exterior glass and promote air circulation by cutting back any bushes that might be obstructing 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 influence the humidity in your home. Here are some common culprits that can lead to roomside condensation:

Sources of humidity in your home 

The most commonly seen way roomside humidity increases is through everyday home activities. 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–up to four gallons or more per day in some homes. Add today’s energy efficient, well-insulated homes and you can start to see why that humidity can often find no way 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. Normally, this is created 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 Hurt My Windows?
One area 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 sign of seal failure and the insulating glass should 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 to be found in your home.

High indoor humidity can result in structural damage and even impact 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 signal that humidity levels are too high. And while window condensation and musty odors might be seen as nuisances, they can evolve into more severe concerns such as water stains on walls and ceilings if left unchecked.

In the same way, left unaddressed, condensation issues can mean 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 cozy and maintaining your windows. If you have any questions about condensation and whether your windows and doors are doing their jobs as they should, give McComb Window & Door in Indianapolis a call or stop by the showroom.

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