Why Your Windows Are Sweating Indoors and How to Fix It

September 27, 2022

The windows in your home are a portal to the outdoors, a way to allow light in while you appreciate the view of your garden, yard or scenery. The last thing you would want to see is a sweaty window coated in a film of condensation.

Not only are windows coated in condensation unappealing, they also can be a sign of a more serious air-quality problem within your home. Thankfully, there’s several things you can try to correct the problem.

What Causes Condensation in Windows

Condensation on the interior of windows is produced by the damp warm air in your home mixing with the cold surface of your windows. It’s especially common during the winter when it’s much colder outside than it is within your home.

Inside Moisture vs. In Between Panes

When dealing with condensation, it’s important to understand the contrast between moisture on the inside of your windows in comparison to moisture in between the windowpanes. One is an indoor air quality issue and the other is a window issue.

  • Moisture on the inside of a window is produced from the warm damp air inside your home collecting along the glass.
  • Existing moisture you see between windowpanes is formed when the window seal breaks down and moisture slips between the two panes of glass, and by then the window has to be repaired or replaced.
  • Condensation on the inside of the windows isn’t a window situation and can instead be resolved by fine-tuning the humidity inside your home. Different things produce humidity throughout a home, like showers, cooking, bathing or even breathing.

Why Condensation on Windows Can Be an Issue

Although you might presume condensation in your windows is a cosmetic concern, it may also be indicating your home has excess humidity. If that’s the case, water could also be condensing on window frames, cold walls or other surfaces. Even a thin film of water can encourage wood surfaces to mildew or rot over time, promoting the growth of mildew or mold.

How to Decrease Humidity Inside Your Home

Thankfully there are numerous options for extracting moisture from the air throughout your home.

If you have a humidifier operating in your home – whether it be a small-scale unit or a whole-house humidifier – lower it further so the humidity inside your home goes down.

If you don’t have a humidifier active and your home’s humidity level is higher than you prefer, look into purchasing a dehumidifier. While humidifiers add moisture in your home so the air doesn’t get too dry, a dehumidifier extracts excess moisture out of the air.

Small, portable dehumidifiers can absorb the water from a single room. However, portable units require clearing water trays and generally service a fairly small area. A whole-house dehumidifier will eliminate moisture across your entire home.

Whole-house dehumidifier systems are regulated by a humidistat, which enables you to establish a humidity level the same as you would choose a temperature via your thermostat. The unit will begin running immediately when the humidity level overtakes the set level. These systems collaborate with your home’s HVAC system, so you will want to contact experienced professionals for whole-house dehumidifier installation the Bay Area.

Alternative Ways to Decrease Condensation on Windows

  • Exhaust fans. Installing exhaust fans near humidity hotspots such as the bathroom, laundry room or above the oven can help by drawing the warm, moist air from these areas out of your home before it can raise the humidity level in your home.
  • Ceiling fans. Running ceiling fans can also keep air moving inside the home so humid air doesn’t get caught up in one spot.
  • Opening your window treatments. Opening the blinds or drapes can decrease condensation by stopping the warm air from being trapped against the windowpane.

By reducing humidity inside your home and moving air throughout your home, you can make the most of clear, moisture-free windows even during the winter.