How to Prevent Condensation on Windows

Condensation forms on windows when the surface temperature of the glass drops below the dew point of the surrounding air. While condensation on windows may not look nice, it’s usually nothing to worry about. The good news is that you can minimize or even prevent condensation with some simple solutions.

 

Just like a cold glass of lemonade on a summer day, window condensation occurs when the surface temperature of the glass drops below the dew point of the surrounding air. While condensation on windows may not look great, it’s usually nothing to worry about. The good news is that you can minimize or even prevent condensation with a few simple solutions.

 

Common causes of window condensation

While window condensation might seem like a problem, it doesn't always indicate an issue. In fact, condensation can suggest that your windows are forming an airtight seal, preventing air leaks and keeping moisture inside your home.

 

Typically, window condensation results from temperature and humidity differences. During summer, hot, humid air outside meets cool, air-conditioned air inside, causing condensation on the exterior of the window. In winter, the opposite happens: cold outdoor temperatures cool the glass, and warm, humid indoor air leads to condensation on the interior of the window.

 

If you can’t easily wipe away the condensation — and be sure to use a soft cloth to avoid fingerprints and streaks — the moisture may be trapped between the panes. This is a sign of a more serious issue, such as a broken seal, which may require professional attention.

 

 

Dangers of window condensation

Although condensation on the glass itself is harmless, excessive moisture can cause problems if left unchecked. Water can drip down from the windows, leading to blistering, cracking, or peeling paint on your window frames. Over time, this can result in warping and water damage, which may ultimately require frame replacement. Addressing window condensation early can help prevent these more serious issues from developing.

 

Condensation in Windows

When condensation forms inside the windows—between the panes of insulated glass in dual-pane or triple-pane windows—it’s a sign of seal failure. This means the airtight seal designed to keep moisture out has broken down. Unfortunately, the only way to resolve this issue is to replace the affected glass. In some cases, you may only need to replace the panes, but in other instances, it could require replacing the entire window.

 

Moisture Throughout Your Home

If you notice regular indoor condensation on your windows, it indicates that excess moisture is present elsewhere in your home. Over time, this can damage insulation, cause stains on walls and ceilings, and, in severe cases, lead to structural damage.

Windows often serve as the first warning sign of elevated indoor humidity levels. It's essential to address the source of the humidity early to prevent hidden and costly issues from developing throughout your home.

 

 

How to stop condensation on windows

Before focusing on prevention, here are a few steps to help eliminate existing condensation on your windows:

 

Open the Windows: Letting fresh air circulate by opening the windows can help reduce or even eliminate condensation buildup.

 

Use a Moisture Absorber: Place moisture absorbers near windows to trap condensation-causing humidity before it settles. These absorbers come in various designs, and some are refillable, making it easy to replace the gel once it reaches its capacity.

 

Get a Dehumidifier: A dehumidifier removes excess moisture from the air and can be particularly effective for reducing window condensation, especially in humid climates or homes with basements. Consider placing a small dehumidifier near areas where condensation is the worst.

 

Pull Back the Curtains: While curtains and window treatments add style, they can trap moist air against the windows, worsening condensation. Simply pulling them back to allow better airflow around the window can help prevent condensation from becoming a bigger issue.

 

 

How to prevent condensation on windows

Preventing condensation requires different approaches depending on whether it forms inside or outside the windows. The first step is to determine where the moisture is coming from. Once identified, use the following tips to stop condensation from forming:

 

Interior Window Condensation

When condensation forms on the inside of a window (roomside condensation), it's an indication that humidity levels inside your home are elevated. Common sources of this moisture include cooking, showering, houseplants, and even laundry.

 

Preventing Interior Window Condensation

To stop condensation on the inside of your windows, start by measuring your home's relative humidity. The EPA recommends using a hygrometer, an affordable tool available at home improvement stores. Some smart thermostats also come with built-in humidity meters. Once you know your indoor humidity levels, take the following steps to reduce them:

 

Open Window Treatments: Closed drapes or shades trap heat against the window, increasing the likelihood of condensation. Try opening window treatments to allow better airflow around the glass.

 

Circulate the Air: Improve air circulation by using ceiling fans in a clockwise direction, even in winter, to distribute warm air more evenly throughout the room.

 

Turn Down the Humidifier: If you're using a humidifier—whether for a nursery, a cold, or integrated into your heating system—reduce or turn it off until humidity levels drop.

 

Ensure Proper Ventilation: High-moisture areas like kitchens, bathrooms, and laundry rooms need good ventilation. Use exhaust fans while cooking or showering, and make sure vents and dryer exhausts are functioning properly. If your home lacks exhaust fans, briefly open windows to allow moisture to escape.

 

 

Exterior Window Condensation

Exterior window condensation occurs when the temperature of the glass surface drops below the dew point of the surrounding air. It is more likely in seasons with higher humidity, such as spring, summer, and fall, especially during cool nights that follow warm days.

 

This type of condensation is most common in the summer due to:

1. High outdoor humidity

2. Little to no wind

3. Clear night skies, which lead to rapid cooling of the glass

 

Getting Rid of Exterior Window Condensation

Since exterior condensation is caused by weather conditions, it’s a common and natural occurrence. It doesn't signal any issues with your windows or the humidity levels inside your home. The easiest solution is to wait for the sun to dry the moisture. However, if you want to speed up the process, you can gently wipe the windows with a cloth.

 

 

Conclusion

It's important to address these factors early to prevent condensation from negatively affecting your home. By implementing these strategies, you can reduce the problem and create a healthier, more comfortable environment. Proactively managing condensation not only protects your home but also contributes to the overall well-being of your living space.