Ventilation system in single-family house without effect = planning error?

Just noticed, now that you mention it. Actually, we replaced all the furniture in the house in 2018/2019. There are only very few pieces of furniture left that made it from our apartment into the house.

In the bathroom, we also ventilate immediately afterwards, (shock ventilation with the window fully open for about 5-10 minutes) so that the mirror clears up again.

The device also measures the humidity. I'll attach a screenshot - supposedly top. But in summer we already had very high humidity, though I don't remember the values.

Yes, unfortunately, rework is really on our to-do list. :(

There are many materials in new buildings that emit gases. Do you have dispersion paint on the walls? Flooring made of vinyl or carpet? That can already produce a lot of odor. Especially in the summer, the humidity inside the house can also increase when it is warm and muggy outside and inside – due to good insulation – rather cool. Then more condensation simply occurs. We have installed a window with an insect screen in the sleeping area and always keep it open at night in the summer. In addition, I have gotten into the habit of creating a draft through almost the entire house early in the morning at six o'clock on hot days. That cools quite well and also eliminates the moisture effect. Otherwise, the emissions will also subside. May I ask what your exterior walls are made of?

Now you also have to turn off the system for one night and then measure. So that we can even know if the device is measuring correctly and if the house is really airtight (in case no BD test was done).

Then you can say whether the system is working properly.

The issue with the odors is actually a concern. No system can handle that, you are expecting too much.

Can you please tell me which device you are using there? I would be interested for myself. Thank you!

I can't say exactly what color we have on the walls: upstairs, however, everything except the hallway is wallpapered and painted, yes. The floor coverings are completely laminate, except the bathroom is tiled and wallpapered. We do not have carpet. I seem to remember that the humidity was very high in our home during the summer and the temperatures were also extremely high (I once read 28 degrees in the bedroom at 8 am). Our wall construction is as follows: brick exterior wall 2 cm air layer 14 cm insulation 035 (glass wool) 17.5 cm Ytong gypsum plaster

Now you also have to turn off the system for one night and then measure. So that we can even know if the device is measuring correctly and if the house is really airtight (if no BD Test was done). Then you can say whether the system is working correctly. The issue with the odors is actually a topic. No system can handle that, you are expecting too much.

BlowerDoorTest (?) was indeed not done. I can also turn off the system during the day sometimes – then the values should go up, right?

Can you please tell me which device you are using? I would be interested for myself. Thanks!

We got a Wolf CWL300 – for my neighbors who have the same system, it seems to work very well.