Exploring the Causes and Effects of Window Condensation

When droplets of water or frost forms on the interior surface of your home’s windows, it’s a sure sign of trouble. This condensation forms due to a difference in temperature between the interior and exterior of your home, which causes condensation when moist air contacts the dry, cool surface of your windowpanes. Although this may seem like a problem with your windows or their installation, window condensation is actually an issue that’s related to your HVAC system and the quality of the air inside your home, including temperature and humidity. Understanding how, why, and when condensation forms and why it must be corrected can bring you closer to enjoying a more energy-efficient home.

Possible Causes of Window Condensation

Window condensation can form in the summer and the winter, due to different effects inside and outside your home. In the winter, condensation forms when the moisture content of your indoor air rises, such as when you take a shower or run a humidifier for improved comfort. Wintertime condensation forms on the interior of your home’s windows, as the air outside is drier and colder than the air indoors. During the summer months, condensation forms on the exterior of your windows when the ambient outdoor air meets the cold surface of your windowpanes, which are cooled from the inside when you run your air conditioning.

Negative Effects of Window Condensation

Many homeowners simply ignore window condensation as an eyesore. While it’s true that condensation will affect your view of the outdoors, it can also cause other long-lasting effects if not properly addressed. Excessive or frequent droplet formation can drip onto window frames, walls, siding, and flooring, causing water damage that may warp wood and dissolve fabric or drywall over time. The presence of consistent condensation on or around your windows may also invite mold growth or pests into your home, which can also affect your comfort and your health.

Solutions for Window Condensation

Condensation on your windows is not always indicative of a poor seal. Because condensation is often related to the temperature and humidity of your indoor air, changing these two characteristics will typically solve condensation problems. If you use a humidifier for greater comfort in the winter, adjust its setting to less than 50% humidity, particularly when the temperature outside is very cold. You can also provide added insulation for your windows by closing your curtains or blinds, which may also help to reduce the amount of work your HVAC system must do to keep your home comfortable in both the summer and the winter. When cooking or showering, make sure to run your kitchen or bathroom’s exhaust fan; if these fans have little or no effect, you may want to consider replacing them or talking to your HVAC service about installing a whole-home ventilation system, which can improve the overall quality of your indoor air, as well as increase the efficiency of your furnace and air conditioner.

You don’t have to live with window condensation and the negative effects it can cause—please visit our website to find out how our HVAC products and services can help you control humidity and temperature for a comfort and efficiency all year long. We also invite you to read through our blog, where you’ll discover even more home HVAC solutions and tips.