Now that the temperature outside has dropped, the windows start to accumulate water vapor. I am assuming that it might also lead to that black stuff forming. Is there a more efficient way of dealing with the condensate than wiping it dry every day?
If you cannot afford to replace the windows then look into adding storm windows. This is simply another window added to the outside of your window that adds another layer of insulation. Usually this increases the insulation enough to stop condensation.
These are common in the US. IDK how common they are in Europe.
This might be bad advice depending on the insulation of the outer walls. If you increase the insulation on these windows, the water might still condensate, but this time on your walls where you cannot see it or wipe it away. A rule of thumb is to insulate the outer walls better than the windows.
And that’s how we got mould this year 🙌 Hopefully the owner will isolate the walls next year…
These are common in the US. IDK how common they are in Europe.
We have roller shutters. . Way better. Those obviously block the light, but since it’s coldest at night and nights in winter are long they help a lot.
But, just like with storm windows it’s not necessarily allowed to add those due to zoning laws and landlords.
In any case, if you’re ready to spend money and alter your building, then just buy new windows. New windows in Europe typically have at least three panes and a metal layer against infrared.
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I’d suggest using a dehumidifier. Alternatively open the windows once or twice a day to reduce the humidity in the room where this is happening.
Dont use a dehumidifier. Just open the windows to let humid air out and fresh air in.
A dehumidifier can help a lot when the room is barely heated. This is also the case when insulation of the building is bad. Some apartments will always be humid, even when opening the windows everyday. In those cases a dehumidifier will do the trick and you’ll get about 2 - 3liters of water out of the room within a couple of hours.
That makes sense if you want to ventilate their air anyway. After all you need to get rid of CO2 inside as well. Fun fact: You don’t need to worry about the lack of oxygen in that context. If the oxygen level have dropped from from the normal 21% do 17% because the oxygen (O2) was magically removed you’ll still be perfectly fine. But if those were converted into 4% CO2 that will make you sick.
Anyway: My point is that a dehumidifier is more often more efficient because it doesn’t involve wasting warm air. It’s also a fairly efficient heater. Dehumidifying, i.e. turning vapor into liquid means that you get the energy used for evaporation back. It’s essentially sweating in reverse. With a typical dehumidifier that means you get about 2 Joules of heat for every Joule of electricity used.
Thank you for the suggestion. My hygrometer shows 65% at about 20C. But the humidity outside right now is like 90% with all the snow and rain. So I guess part of the problem might be that the room is too cold.
See the thing is, humidity is always given relative to the Dew Point in percent. If I assume 0°C for outside with 90% humidity thats 4.6 g/m3 of water. In your room with 20°C and 65% humidity its 11.2347 g/m3
So if you open your windows your humidity will decrease. Warmer air can store more water.
Under ideal conditions you could get to 27% at 20°C which you will never reach, but opening the windows for 5 minutes (ideally two windows on opposing sides of the house to get a good draft) should get you below 55% already. Repeat it three time a day and you will stay below 50% humidity.
Also, thanks for the detailed calculations. I never realized how that actually worked
I’m kind of shuddering at the thought of opening my windows in this cold, but ok, I’ll try that)
Just checked the windows temperatures. Interestingly, the temperature varies quite a bit along the surface of the window. The middle of the window is about 18C but the bottom measures at about 13C, which is exactly the dew point for my 20C / 65% (thanks for the calculator, btw).
These windows need thicker glass that ensures better insulation.
