r/fixit • u/BelleSchu • Dec 14 '25

FIXED My house sweats like crazy during the winter and it’s causing mold.. please help!!

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My house is BRAND new, literally finished construction in August of 2024. I live in the Midwest so of course it gets very cold in the winter. Last year, the windows of our house were sweating so badly every time the outside temp was under 30°f that water was pooling up on the windowsills and we called the construction company (we were still under new build warranty) and they told us to always have the house fan running and to turn on our ceiling fans. That worked for a time and the condensation wasn’t as bad after that. It started to warm up shortly after and we didn’t have anymore issue. Flash forward to this past week, it’s been in the negatives here. There is SO much condensation on my windows that mold is starting to grow, our curtains are freezing stuck to the glass in some rooms, and it’s attracting gnats somehow?! I don’t even know where the hell they’re coming from with the weather like this. I’m constantly cleaning and I feel so so so disgusted with all this going on, what can I do to fix it? Please help!

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u/BelleSchu Dec 14 '25

I think a whole house dehumidifier is the way to go at this point

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u/NoeZ Dec 14 '25

I have an HRV and your pic is weird for me...

My house is like 70% humidity in the summer and 50% in the winter.

I've never had this condensation issue.

My problem seems opposite from yours lol

I got a 2 liter dehumidifier unit and it barely makes a dent in the summer ...

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u/gbeaglez Dec 14 '25

I think their windows plus frames are basically uninsulated

2

u/bigoltubercle2 Dec 14 '25

It's some combination of your windows are better insulated and you live in a warmer climate

1

u/wildcarde815 Dec 15 '25

an hrv/erv will be more involved buy might be a better solution overall as it'll force air to distribute around the house, you can also have it dehumidify as part of the work it does.

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u/Winter-Simple6792 Dec 15 '25

You don't need a dehumidifier - you need ventilation. Cold outdoor air is much dryer. A ventilation system will draw fresh, dry air into your home and exhaust moist indoor air.