I bought an old house (1980s) that went through some reconstruction 5 years ago. We moved in July, so 2 month later we noticed higher humidity in the house, mostly by drops on the windows in the morning. I want to share my experience and eventually a solution. I hope.
Current humidity in house
We have 3 floors:
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Basement
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Ground floor
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Second floor
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In the basement, we mostly keep windows open, or it has a small tube for ventilation in two rooms.
One room is also utility room -> with heater for whole house, so it's pretty warm. I don't care that much about basement, I think I will look into it more when we am satisfied with room we spend most time in, so ground and second floor.
- Ground floor has a kitchen, living room and bathroom. Wife cooks daily, irons weekly and bathroom is also heavily used.
I started tracking humidity with analog hydrometer. To my surprise, it was 80% in the morning. Not something I would like to see, but I expected there will be work needed on the house.
- Second floor seems fine in terms of humidity. I bought ikea VINDSTYRKA and connected it to Home Assistant,
to see the trend. Surprisingly it's around 50%, so nothing to do here.
Ground Floor
In October, we had to clean windows almost every morning. Water drops were 5-10 centimeters from the bottom of the windows. Not something we would like to do daily, especially since my wife has 5 flowers on each window, and me cleaning windows would result in broken flowers, sooner or later.
Simple solution for window cleaning is to upgrade windows. Current windows are 19 years old, and by upgrading them to triple-pane windows, we would get rid of the problem with broken flowers. But since triple-pane has higher price, doesn't make sense to do it for windows, which would be replaced in 10 years (windows mostly have 30 year lifespan). And it still wouldn't solve the main problem, which is high humidity in the house.
Another option is to buy a dehumidifier. Brother build a house few years ago, he had two from the start, so he borrowed me one to try it out. Rohnson R-9575, seems nice, but wife was complaining first day abot the noise (she later got used to it). But it works, keeps humidity around the set value 65% - (62%-68% range, so -+3%).
Later in December, I set wanted value to be 50%. Rohnson is located in the center of the house, so corners of the house have higher humidity - 60-70%. In December, opening windows does lower humidity below 50% easily.
In terms of cost of running dehumidifier, it has 26kWh per week, ~110kWh per month. In Slovakia on January 2025, 1kWh is 0.1557€, so it costs 16.19€ per month.