Are your windows “sweaty”? This sweat is called condensation and can be a normal part of a window’s life. When warm indoor air mixes with cool outdoor air, condensation forms; it’s similar to how your bathroom mirror fogs up when you take a hot shower.

But what if you have windows that are experiencing too much moisture or condensation? That can indicate that there is seal failure, and you may need new glass or windows. So how can you tell if your window condensation is normal or not? We’ll share how to spot the differences below. Also, make sure to keep reading for tips on how to reduce condensation in the first place. 


The greater the differences between outdoor and indoor temperatures, the more likely condensation will become visible on your windows. Thanks to our Midwest winters and harsh summers, this is a common problem for many homeowners.

There are two types of condensation: interior and exterior. As mentioned, interior condensation is usually caused by freezing outdoor temps and excess moisture inside the home. As the outside temperature drops, the inside surface will get cooler, and condensation will form. 

window condensation


Here are some everyday things that can cause the temperature imbalance that brings on condensation:

  • Cooking
  • Showering
  • Dishwashers
  • Pets
  • Plants
  • A clothes dryer that doesn’t vent properly
  • Large groups gathered indoors

Why Newer Windows Can Build Up Condensation

Suppose you have brand new windows and notice more condensation than when you had older windows –– this is most likely happening because of the airtight seal. Less air is entering your home from the outside compared to the air leaking from older windows that dissolved the moisture before it could collect.

Other possibilities for condensation build-up on your newer windows can either be extremely humid summers, extreme temperatures, or new construction/remodeling in your home. Typically, a newly-built or remodeled home will have wood that’s still a bit wet. The good news is that humidity will naturally clear out of your house over time.

You want airtight seals; you want windows to do their job.

By following a few simple steps (listed below), you can minimize the condensation problem.


Exterior condensation is when “sweat” forms on the outside pane of the window; this typically occurs in the summer. External condensation can happen for many reasons but is not of concern. The condensation usually disappears quickly and doesn’t affect the interior of your home. 


Interior condensation on windows occurs when your cold windows come into contact with warm & humid indoor air. This is most common during the winter months which leaves your windows cold, and the air in your home warm. This is most common in rooms such as bathrooms and kitchens where daily activities such as cooking or showering can contribute to interior window condensation.

windows during the winter


What if the condensation doesn’t budge? It could be a sign of seal failure on old and drafty windows. With an ineffective seal, it’s easy for moisture to find its way between the glass panes, forming condensation.

Too much condensation can lead to peeling paint and mold or mildew growth, resulting in various health problems. It can also cause window frames and other wood components to rot.

To prevent this type of issue, we recommend investing in new energy-efficient windows. Windows with broken seals will no longer provide the level of insulation necessary to keep the home comfortable, energy-efficient, and condensation-free.

Follow the tips below to reduce your window condensation. If the problem persists, it is best to consult with one of our Design and Energy experts. Depending on the issues found, you might need to either repair or replace your windows. 

excessive window condensation


Here are some suggestions to reduce the risk of condensation forming on your windows:

  • Keep your home ventilated by opening your windows to allow air to circulate. Open them for a few minutes each day, especially after steam-producing activities. Investing in a ventilation system can also help.
  • Open blinds and drapes. Heavy window treatments can restrict the flow of air against the windows.
  • Keep the indoor temperature at a constant level, especially during winter. Having shifting room temperatures allows for warmer air to release moisture into the room.
  • Reduce moisture sources. Turn down the humidifier on colder days.
  • Limit plants or keep them all in one room and avoid overwatering.
  • When air drying laundry, open some windows so that moisture can escape.
  • As for the placement and positioning of your furniture, add small spaces in between fixtures and walls. Doing so gives room for air to circulate and not accumulate in one spot.

living room windows

Condensation can be a serious problem. If there’s too much condensation on your windows, don’t wait until problems occur before you have your windows checked. Contact us today; we are here to help you with your window concerns.


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