As a homeowner, you probably don’t think often about your windows. Other than sliding them open from time to time to let in some fresh air, and wiping them down to maintain a clear view of the outside, you just leave them alone as you go about your daily life.
This story can change, however, when the windows start to fog up. If your windows are regularly fogging up, this phenomenon can be frustrating and may lead to concerns that a serious problem is to blame. So, what’s this all about? Why do windows fog up and what can you do about it? We’ve got the answers below.
Why Do Windows Get Foggy?
To get to the heart of this matter, we have to dive into just a bit of science. When you see a window that looks “foggy”, what you are really seeing is condensation. Moisture condenses on the surface of the glass, developing a layer of water and clouding up some or all of the window pane.
Condensation occurs when warm, humid air comes into contact with a cold surface like the glass of your windows. Warm air is capable of holding more moisture than cold air, and it will leave some of that moisture on the surface of something cold – and your window glass is likely to be some of the coldest places in your home.
Where is the Condensation on your Window?
Condensation on the inside pane of the Window
If you have warm, humid air inside your house and cold outdoor temperatures, foggy windows are a possible outcome. In many cases, this doesn’t mean that anything at all is wrong with your windows. It can just be a matter of the conditions that are in place in and around the house. With that said, it is possible that something is wrong with the windows, so it’s a good idea to look a little closer.
Condensation on the outside pane of the Window
The above is true during the winter months when warm, humid air inside of your home comes in contact with the cold glass of your window. The opposite effect is true in the summer when warm, humid air outside your home comes in contact with the air-conditioned, cooled-down glass of your windows, which, under the right conditions, will cause condensation to form on the outside pane of glass. This is also not a concern and you can expect this to clear up shortly after the daytime sun reaches your window.
Condensation on the in between the panes of the Window
A double-pane window has a seal that holds air between the two panes. This is a modern design that allows windows to insulate far better than the single-pane windows of the past. When homeowners see a foggy window, they often assume that the moisture is between the panes and that the seal has broken to allow moisture to get in where only air is supposed to be.
If the moisture is, in fact, between the window panes, the seal has likely broken, and the window may need to be replaced. But it’s not wise to jump to that conclusion. It’s possible that the condensation could actually be on the inside or outside of the window, rather than between the panes, meaning that the seal should still be intact.
Quick Test to Check Window Condensation
Before you get too deep into analyzing this situation, you can look at one thing to determine if this is likely a seal issue or just a matter of humidity and temperature. Is more than one window fogged up in your home? If you are seeing this problem across multiple windows, it’s highly unlikely that seals are to blame. The chances that the seals in all of those different windows have failed are very low, and you are almost certainly looking at weather conditions as the cause of the fog.
Pro Tip
Worried about seal failures in your windows? Check to see if all your windows are "foggy". If you are seeing this problem across multiple windows, it’s highly unlikely that seals are to blame. The chances that the seals in all of those different windows have failed are very low, and you are almost certainly looking at weather conditions as the cause of the fog.
It's when just a single window is fogged up that you might need to consider the possibility of a bigger problem. But even then, you’ll want to look closer before assuming the worst. Take your finger and run it along the inside of the window while standing in the house. Does your finger get wet? Moisture on the inside of the window means it’s not a seal problem but rather a matter of normal condensation. If you don’t find that the moisture is on the inside of the house, go outside and do the same test. Just the same, if you find the condensation is on the exterior of the window, your seals are probably fine.
Taking Steps to Reduce Condensation on Windows
If you have gone through the process above and feel like a broken seal is to blame, reaching out to an experienced partner like Nordik is the appropriate next step. We will come out and assess the situation, and if we wind up replacing the window with one of our RevoCell windows, you can be sure that no other problems will be popping up anytime soon.
On the other hand, if the seals seem to be fine, you’ll still want to find a way to at least improve this annoyance so your windows stop fogging up regularly. While there is a part of this phenomenon that just comes down to conditions that are out of your control, there are a few things you can try –
Use HVAC equipment to manage interior humidity. If you are able to keep the humidity levels in your home down, it’s far less likely that you’ll experience fogging of your windows during the winter. Having a dehumidifier added to your HVAC setup will do this job nicely. There is an upfront cost associated with this project, of course, but you’ll get to enjoy the benefits for years to come. Not only will fogging be less likely to occur, but the house should be more comfortable with a dehumidifier running.
Clean your windows often. When windows get dirty with grime and buildup, that slightly rougher surface is a perfect place for condensation to form. By regularly cleaning your windows, you will keep the glass smooth and it will be a little harder for much condensation to form.
Use your curtains. By keeping the curtains closed, you add a layer of insulation between the windows and the warm air that is circulating throughout the home. So, if it’s a cold winter day outside (and it’s dark anyway), you can keep the shades or curtains open and it will be less likely that condensation is going to accumulate in any significant way.
We hope you find these tips on window condensation helpful! For other tips and tricks with regards to windows and doors to hesitate to check out our Ask an Expert blog !