ᐅ Humidity in the Bathroom

Hello everyone,

We have been living in our own home for six months now.
At the moment, there is something that worries me a little because I don’t know if it is normal or not.

Since we moved in, we have had a humidity meter in the main bathroom. I check it regularly. When the humidity is above 60%, I open the window (whenever I am home) to reduce the moisture.
During the winter months, I lowered the humidity to around 50% (10 inches) and it generally stayed there until someone took a shower or bath. After that, I would open the window again and everything was fine.

Currently, however, I notice that despite leaving the window open for a long time at times, I can hardly get the humidity below 55%, and – what worries me even more – the humidity rises continuously again after closing the window, even though no moisture is being added (no showering or bathing). This morning, the reading was 75%.

Sometimes I can explain this: for example, warm air (in summer) holds moisture less effectively than cold air (winter), which may be why it is harder to get the humidity below 55% currently.
But why does the humidity continuously increase again when the window is closed, even though it stayed consistently low during the winter months? The only idea I have is that with the current temperatures, the walls are warmer than in winter, which causes more residual moisture to be released and enter the room.

PS: There is actually an extractor fan in the bathroom that is supposed to turn on at high humidity levels. However, it has never worked properly from the beginning (and the electrician has not found the fault – the control unit has already been replaced three times). Therefore, we still mainly rely on window ventilation.

What temperature do you usually have in your bathroom? Does it stay cold after ventilating following a shower, or does the temperature settle back to a higher level?

Final schrieb:
What temperature do you have in the bathroom? Does it stay cold after airing out following a shower, or does the temperature return to a higher level?

Since it’s the bathroom that the children also use, the underfloor heating remains set at a constant temperature—around 21–22°C (70–72°F). So after airing out, the temperature goes back to the initial level. This is easy to notice, especially in the evening or at night when the outside air is cool and the windows are open after bathing or showering—some time after closing the windows, the bathroom becomes comfortably warm again.

f-pNo schrieb:

But for what reason does the humidity continuously increase again with the windows closed, even though it stayed consistently low during the winter months? The only idea I have: With the current temperatures, the walls are warmer than in winter, causing more "residual moisture" to be released and enter the room.

Hello,

have you tried placing the humidity meter in other rooms in the house just for fun to test how the humidity behaves there?

This way, you could at least narrow down whether it is "just" a problem in the bathroom, or a problem throughout the entire building?

Regards,

Dirk

Doc.Schnaggls schrieb:

Have you tried placing the moisture meter in other rooms in the house just for fun to see how the humidity levels behave there?

That way, you could at least narrow down whether it’s “just” a problem in the bathroom or an issue affecting the entire building.

I’ve already thought about that 😉.
We have a second moisture meter in the living room—it’s consistently showing around 50%.
But just to be on the safe side, I asked my wife yesterday to pick up a 3-pack at the hardware store. I’ll distribute those in the bedroom, hallway, and utility room.
I think the other floor is not problematic since the living room, as mentioned, shows no issues, and the exhaust fan in the shower bathroom operates with a timer and humidity sensor.

Then I am curious to see the results.

Do you happen to have a special plaster or a particular wallpaper in the bathroom that might help regulate humidity?