window condensation issues

What Causes Window Condensation?

window condensation issues

Many people incorrectly assume that when there is condensation on their windows that the windows are to blame. Windows do not cause condensation but are often the first place where condensation is visible. It’s much easier to see condensation when it’s obstructing your view, such as with windows and mirrors, as opposed to condensation on a solid surface, such as walls. In most cases, condensation on your windows means the humidity inside your home is high, and steps should be taken to reduce it. If you choose to ignore those early signs of high humidity, you risk damages to the home, such as mildew, paint peeling, wood rotting, floors buckling, insulation deteriorating or moisture spots on the walls and ceilings.

What Causes Condensation in the Home?

Condensation is the effect of warm, humid air coming into contact with a cold surface. Warm air holds more moisture than cold air, so as the air cools moisture will form into condensation on surfaces.

What Makes the Air Inside my Home so Humid?

Day to day life can cause quite a bit of moisture to be released into the air in your home. Everyday activities such as showering, bathing, cooking, laundry, cleaning and even breathing will add moisture to the home. Then in today’s energy efficient construction moisture tends to stay within the home. Even plants will release humidity into the air.


high humidity homes

Are there Health Risks to a Home With High Humidity?

Contrary to what was once popular belief keeping the humidity high in your home can lead to health risks. Molds and mildews tend to thrive in moist areas and often become airborne causing health concerns. Allergic reactions, sinus and nasal irritations, infections, respiratory issues, dizziness, lethargy, and asthma attacks are some of the potential health risks from mold and mildew.

What Risks are there for the Structure?

Indoor air with high amounts of moisture has a higher pressure than outdoor air, so it will continually push out on on the structure in an attempt to equalize pressure with the outside. Potential damage includes destroying the insulation, causing the paint to peel or blister, staining the walls and ceilings and structural damage to the floors, wall supports or foundation.

When is the Highest Risk Time for Condensation?

  • Chicagoland is a prime area at first for condensation since we average less than 35 degrees during January.
  • During the summer and fall due to particularly damp air.
  • Reverse condensation sometimes happens when it’s hot and humid outside, but cool in the home. Condensation will appear on the outside of the windows. You’re more likely to experience this if you have plants surrounding your windows.
  • If there is a quick, significant drop in temperature, you’ll most likely experience temporary condensation.
  • The first year after the structure is built or remodeled you’ll experience condensation as the building materials fully dry out.
  • Bay and Bow Windows experience condensation more often than traditional windows since they stick out from the rest of the structure.

How do I Tell the Difference Between Normal Condensation and Condensation from Bad Seals on my Windows?

The easiest way to tell the difference is to run the finger test. Run your finger along the glass of the window in question. If your finger stays dry, it’s the seal, but if it gets damp, then it’s due to humidity.

My New Windows Have Condensation Problems, but my Old Windows Didn’t, How Come?

Most likely your old windows weren’t as energy efficient as your new ones and had cracks that allowed the moisture to escape.

damage to home due to condensation

Outside Temp

Humidity %

What Steps Can I Take to Reduce Indoor Humidity?

  • Increase Ventilation by opening the windows with condensation on them for a few minutes to allow the humid air to escape.
  • Make sure all sources of humidity are ventilated, such as kitchens, showers, and laundry rooms.
  • Make sure you have quality storm windows installed to create an additional barrier between the exterior and interior air.
  • Make sure your humidifier is set to the recommended level for the winter temperatures you are currently experiencing. You can also purchase a humidity monitor to keep an eye on the humidity level in your home.
  • Waterproof your basement to minimize moisture seeping in from the ground.
  • Use a dehumidifier in any troublesome areas of the structure.


Chicago’s Best Solution for Window Condensation

American Thermal Window has over 35 years experience installing and replacing Double and Triple Pane Windows throughout Chicagoland and is considered Chicago’s top rated window and door company. Everyone on the team is top notch and very experienced in selling and installing Double and Triple Paned Windows. The showroom, located at the corner of Milwaukee and Central Ave in Chicago offers many displays showcasing the different Double and Triple Windows available.

Contact American Thermal Window

To learn more email or call (773) 774-3131