Why are my bedroom windows fogging up in cold weather, and is there a way to fix it?
Asked by Claudina Viana 
8 months ago
Last Updated: May 4, 2024
I’m really hoping someone can help me figure out what’s going on with our new windows. We had them installed in January, and now that it’s -5 degrees outside with the windchill, the bedroom windows are all fogged up. It’s so weird because the living room and other rooms are fine. Any ideas on what might be causing this? It’s driving me crazy!
If you’re noticing condensation in between the window panes, it means the seals have already blown. Whether it’s on the inside or outside, condensation occurs due to differences in temperatures and humidity levels, which ideally shouldn’t happen.
The condensation is on the interior of the windows. Even after replacing the original windows, this still occurs. We keep the heat on, so is there a way to prevent this?
We have a spacious patio door and living room windows and none of them have this issue. The bedrooms affected are all on one side of the house.
How new are the windows? They should still be under warranty for replacement. If not, you might want to reach out to a glass repair specialist like Glass Doctor. It seems like the seals are damaged, causing the window to get cold inside while the house is warm, leading to condensation.
Just got them replaced in January 2023.
I’m also worried because it’s going to be -40 degrees here soon, and if there’s this much condensation, it could freeze completely. I don’t think brand new windows should have this issue. I’m not an expert on these things, so I’m not sure if it’s a window problem or something with our house
It’s important to reach out to the company who installed them for warranty purposes
You should definitely try to get them replaced under warranty. Unfortunately, there is no DIY fix for this issue
Are those windows double pane with sealed glass units?
I believe triple pane windows could be the solution.
If you’re experiencing heavy condensation on triple pane windows only in the bedrooms along the same outer wall when the outside temperature is -5*C, including wind chill, that sounds like a challenging issue. Could those troublesome windows be on the side that faces the wind?
One window is looking out at our neighbors’ house while the other overlooks the yard where it tends to be windier.
Hey , I had the same company replace my windows in January and none of them have the same condensation issues as the bedrooms.
Hey , I’m worried that once it gets to -40 here, your windows will freeze completely.
Hey , if some of your windows don’t have condensation, that probably means the ones that do have a faulty seal. You should get those ones replaced before your warranty runs out.
Hey , the moisture isn’t trapped between the glass, it’s actually on the inside of the window. I can easily wipe the water off.
Hey , do you know why the other large window doesn’t have condensation? It could be due to a faulty seal around the window.
Hey , what did the installer mention?
The larger windows on the opposite side of the house do not experience this. I suspect it may be due to humidity from the bathroom situated between the bedrooms.
Make sure to use dehumidifiers in situations like this
Wondering why there’s so much moisture in your house? Have you checked if a humidifier is on? Do you use exhaust fans in the bathroom and kitchen? Any other sources of humidity like indoor pool, hot tub, or water garden? Make sure vents below windows are fully open to circulate air.
We don’t have a humidifier. We do have a bathroom fan, but the pictures were taken before anyone showered. I don’t always use the kitchen exhaust, though I probably should. We don’t have a hot tub, and I struggle to keep plants alive. Each bedroom has a vent right under the window. When I took the pictures, the thermostat showed 23 degrees Celsius. I wasn’t sure if this was normal or if there was too much moisture. One window was even dripping, which seemed excessive, and winter hasn’t even fully arrived yet.
It’s really humid. There must be something contributing to the humidity.
Seems like you’re dealing with a lot of humidity in the house for some reason. If the airflow to your bedrooms is low, it can lead to high humidity in those areas. Figuring out the source of humidity and condensation can be a bit tricky. It’s important to be patient and not rush to conclusions too quickly. Double-check that all exhaust fans are working properly and venting outside. New windows can make your house much more airtight, causing humidity levels to rise. If your old windows were really drafty, they might have helped control the humidity to prevent condensation. Best of wishes to you.
I am up here in Canada too, can’t believe all this snow! Your bedroom is probably the farthest from your furnace, eh? Make sure your floor vents are open. How high do you have your furnace humidifier set (shouldn’t be more than 45-50% humidity)? If you see condensation between the windows, it means the seal is broken. If it’s on the outside, it might be more of a circulation problem. Try running a fan to circulate the warm air, or consider using a dehumidifier if you’re in a wetter province.
Is the humidity setting on your HVAC system too high? Try lowering it to below 30%.
If you see water inside the window at home, it could be a sign of excessive humidity indoors.
The bedrooms might be cooler because they are farther from the heat source or facing a different direction.
When we moved in, I noticed more humidity in the bedrooms with closed doors. Once I got a lid for the fish tank, no issues!
Hey, do you have a humidifier?
Is it possible that the bedrooms are situated near a shower? Are the heat zones functioning properly? Sometimes this happens when the thermostat is positioned too close to a source of moisture.
Your home has too much moisture, which can lead to issues like mold growth and uncomfortable humidity levels. To address this, consider getting a thermometer with a humidity sensor to track levels in your home. Typically, a comfortable humidity level is between 30% – 45%. You can reduce moisture by using a dehumidifier or installing an HRV unit, which helps control ventilation and humidity levels. In the meantime, try using towels to dry windows, keeping doors open for air circulation, and opening windows and doors to vent out stale air. Good luck!
Hey everyone, just wanted to say thanks! I’ve purchased some humidity testers that should arrive later today. I’ll let you know the humidity levels once I find out and I’ll probably have more questions since I’m not sure where to begin fixing the problem.
If it were due to humidity, it wouldn’t just be select windows. Your thermostat should be able to display the humidity levels as well. Personally, I’ve experienced this issue with my glass French doors when there’s a significant temperature difference between indoors and outdoors because they are single-pane. The outer pane of your window is colder, leading to condensation. The gas layer and additional pane help insulate the outer pane from the inner one. I suggest reaching out to the window company and requesting a replacement.
Are your HVAC vents sweating at all?
Nope, they’re not. Our thermostat doesn’t show humidity levels. I actually got some humidity testers, and it’s at 49%, so I’m planning on contacting the window company today to discuss this.
Hey , remember it’s recommended to keep the humidity level below 35.
Could this be a dehumidifier? It’s connected to my furnace and has a hose leading to a drain, so I’m guessing it is.
Hey , just to clarify, this is a humidifier, not a dehumidifier.
Hey ! I was actually looking for a dehumidifier, haha. Thanks a lot!
Hey Patricia, it’s possible that this is the issue. There’s probably a controller (a humidistat with a high setting) that is connected to your furnace or thermostat. Can you snap some pictures of the wiring connected to it?
Has been working on the project for several months now.
John has been dedicated to this project for a while.
I don’t think the outlet has ever been on. I’ve had the house for 3 years and never used it. I didn’t even think about it until the new windows were installed.
Can you check if there’s a waterline running to ? It’s probably a 1/4” tubing connected to a nearby water pipe. Follow it back to find a tapping valve that you can turn off to shut the water off to the humidifier. Give it a try to see if the windows dry off.
I did a quick search and found out it’s actually a “Wait 6000” whole home humidifier. The controls are located at the top of the unit.
Hey, , your water may be running without you even noticing. Just turn off the water supply to double-check.
I just tested the humidity in the house, it’s at 49%. Is that enough for this to be happening? I reached out to the window company, but I’m still waiting to hear back from them.
The humidity level seems pretty high. I wonder what the temperature is like on the inside surface of the glass and outside. Do you know if the insulated glass units are sealed and gas-filled for the specified insulation level from the manufacturer? Have you tried checking the humidifier? The window people might use it as a defense against taking any action.
Your previous windows had drafts, which prevented them from steaming up. I’m in Nova Scotia, Canada, and I work for a window company. It seems like there’s too much humidity in your bedrooms, as I’ve received calls from others with the same issue. Your new windows are airtight, so the airflow has changed. You could try using a fan in the room to see if that helps. Feel free to reach out if you need more information.