Image shows a window covered in water droplets. The word "Condensation" has been written into the droplets, with small drips going down the window from the word.

Summer Sweating– Don’t panic!

Condensation is usually most commonly seen as a winter occurrence. However – as we move into the warmer months and we turn on our air conditioners- (hopefully!) we may see the development of sweating on the exterior of the windows. Let’s dive into how and why this occurs.

Inside our homes in winter, we turn up the heat, creating a higher humidity level in the home, making the air inside the home warmer than the extremely cold temperatures we see here in Wisconsin. During the winter, you may notice sweating or condensation forming on the interior of the windows. Vice-versa as the Wisconsin weather heats up outside, the air in the home is now cooler than the air outside the home. This has an impact on windows, no matter which end of the spectrum we are on. This may seem like a reason to be alarmed or may leave you feeling like the window is defective or lacking efficiency- when in fact, that is not the case.

As the sun heats up the glass on the outside of the home, the Low-E coating on the window helps trap the heat outside. The entrapment of the heat outside is a good thing and one of the many reasons to have energy-efficient windows in your homes. What happens when the sun goes down and we settle into a cooler summer night? The glass will actually begin to cool from the outside at night. The low-E coating minimizes the heat transfer from the inside, so the outside glass surface can cool notably below the outside air temperatures. With just the right mix of inside temperatures, accompanied by outside temperature- then adding the outside humidity-the windows with Low-E shield can develop condensation.

The reason for the emphasis on the Low-E coated windows forming condensation is to point out that the energy-efficient product (like a window with Low-E coating) is doing its job, while inefficient, outdated, poorly insulated, or single pane windows generally do not form the condensation. The energy-efficient windows make it near impossible for the heat/cold to transfer in through the glass, which keeps the exterior side of the window at the temperature of the air outside, and the interior side of the window at the temperature of the inside of the home!

Rest assured that if you experience condensation, this is most likely a good indication that your Weather Tight windows are working effectively. Most homeowners find that during the early morning hours or once the sun has set in the later hours of the night, condensation presents itself on the outside of the windows since the early mornings & early evenings tend to be a cooler time of day. As the day progresses and the temperatures climb, the condensation will dry up on the exterior of the glass on its own. As the condensation dries, sometimes it can leave unsightly water stains. Most Weather Tight windows can be cleaned with ease from the inside of your home.

If you are experiencing a persistent issue with condensation that may not reference the climate changes above, please feel free to contact our service team at 414-459-3888. No time to call—no worries—we also offer a live web chat feature during normal business hours, where you can speak to one of our friendly staff members who can help with your concerns.

Until then, have a safe and warm summer!