What Causes Windows To Fog And How To Fix It

When you crank your AC system during the hot and humid months, you rely on your windows to keep cool air in and the hot, sticky air out. However, when you notice fog and moisture on your windows, there might be a problem.

There are plenty of reasons for moisture build-up on windows, and some of them are pretty normal while others could be a cause for alarm.

Fog Location

To figure out what causes your windows to fog up, you must first identify the location of the fog. Is the fog on the exterior, interior, or between the glass panes? 

Fog on the inside of your windows occurs when the temperature inside is lower than the temperature outside, such as when you have the AC running. Temperature differences will cause your window panes to trap some moisture from the inner air since the space between your thermal window panes insulates the warmth, causing condensation.

Condensation build-up on the outside of the window occurs when the exact opposite occurs. When the outside temperature is lower than the temperature inside, moisture can build up on the exterior glass. This often occurs during very cold nights and isn’t often a cause for alarm.

Moisture or condensation between two panes of glass occurs when you have a real insulation problem with your glass windows. If the moisture remains and continually builds up to a point that it starts dripping down the pane, it can cause the following problems:

  • The fog obscures the light coming in, making your rooms darker and cooler.
  • It impedes the energy-efficiency and insulation properties of your windows
  • Too much moisture getting trapped between your panes can wear down seals and eventually rot frames.

How to Fix Window Condensation 

First of all, controlling the humidity levels within your home is a simple way to prevent too much moisture from accumulating during colder months. You will often notice foggy windows early in the winter mornings when the air outside is coolest.

When moisture is trapped on the interior of your windows, using a dehumidifier can help remedy the situation.

However, if the fogging is happening between window panes, it could be time for window replacement. It’s always a smart decision to shop for new windows that will block condensation and moisture accumulation and give you a decent head start on Mother Nature!

Midwest Roofing, Siding & Windows Can Help!

Are your windows frequently fogging? It could be time for replacement windows. Midwest Roofing Siding & Windows is one of the 15 Pella Certified Contractors in Minnesota. We will help you choose the right size and best style while working within your budget. Contact us today to learn more about the benefits of our replacement windows, such as improved energy efficiency, noise barrier, home comfort, reduced maintenance, increased home value, and lowered heating and cooling bills.

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