Too high humidity in the apartment. 60-70% in winter

Good day,

I am new here and hope that you can help me (although I am currently not building myself):

We recently moved into a new apartment (newly painted), third floor, the building was constructed shortly before the turn of the millennium.

I noticed that the windows, especially in the morning in the bedroom, study, and kitchen, are fogged up on the inside edges / water droplets are visible. Some windows are older wooden windows, others are skylight windows with metal frames.

I then bought two thermometers/hygrometers from the company TFA and placed them in the bedroom and kitchen. The humidity was between 60-70%.

I have read through some information on the internet and gathered various tips. We air out at least twice, usually more often during the day by ventilation through opening windows fully with a cross breeze, about 5-10 minutes maximum, heating turned off during that time. The temperature in all rooms is between 19 and 20 degrees. Laundry is not dried in the apartment, after showering and cooking we also ventilate intensively and turn on the ventilation, as well as when the washing machine has been running.

We do notice that during ventilation the humidity drops to a range of 40-45%, but within minutes then quickly rises again to at least 53% and then more slowly moves toward 56-60%. In the morning it is about 63-68% in the bedroom, in the kitchen 61-67% (while cooking it goes even higher despite ventilation).

I have placed moisture absorber granulate in the kitchen and bedroom, which unfortunately did not bring any improvement.

I do not know this problem at all from my old apartment, and unfortunately currently do not know what to do next. I would now start to document it in writing and then address the landlord, but I wanted to first ask here if anyone perhaps has further tips on what I could do.

Thank you very much.

Best regards BPE

Hello,

since the problem exists in all rooms, I do not assume a structural issue.

You can only get it under control permanently by ventilating. If the humidity rises so quickly, your walls are already relatively damp. It takes time to get them dry to a reasonable level. Therefore, ventilate, ventilate, ventilate.

And the warmer you make the apartment, the faster you will dry it out. Turn the temperature up to 23 degrees and ventilate more often. The greater the temperature difference between inside and outside, the faster you will dry out the apartment.

And when ventilating, the duration does not matter. You basically only have to exchange all the room air once. Ideally, open opposite windows if there is some wind. Then it takes less than a minute for the air to be exchanged.

The air then saturates with moisture again, and as soon as that happens, you can actually ventilate again.

Hi,

thanks for the answer.

So, the problem does not exist in the living room. The windows there are never fogged up or damp.

As mentioned, we have only been living here for a short time and have always ventilated as described above. If the walls are already damp now, then it must be due to the previous tenant's improper behavior, right? The landlord apparently also told my girlfriend that, for example, the windows and shower seals showed mold when the previous tenant moved out.

Structural reasons are definitely to be excluded, for example because of the newer windows?

Would it make sense if I set up an electronic dehumidifier for a short time?

Thanks and best regards
BPE

Heating and ventilating is all you need to do.

I also know and use the thermometers from TFA in conjunction with a climate logger for humidity monitoring.

The rarely used rooms regularly settle just under 20° at just over 60% relative humidity. However, more like 61/62%. In this case, only airing out and slightly increasing the temperature helps.

That is also probably the reason why the relative humidity in your living room is below 60%, because it is presumably 1-2° warmer there. In all rooms, more or less the same absolute humidity will be present; the difference is made by the temperature.

Make sure you keep the rooms between 20 and 21°, and the necessary percentage points will drop.

I also suspect poor ventilation by the previous tenant. Your behavior sounds good. Try setting the temperature a little higher and observe the humidity during the winter.