Noise generation in the ventilation system

I would measure the CO2 content and the humidity at some point. Are there also silencers that are mounted directly on the plate valve? I have these telephony silencers in the basement.

Yes, of course there are also dampers directly for the valves. I would suspect here that the runs from the kitchen, etc. are quite short and the valve quantities for that possibly quite high. This leads to excessive noise development compared to the supply air valves.

Absolutely right. Both the way from the plant to the kitchen, as well as to the bedroom, are very short. In the other rooms, especially in the children's rooms, you actually don't hear anything at all. Can you send me a link via PM where there are such dampers? I couldn't find anything spontaneously on Google.

Thank you very much in any case.

The dampers are called "insertion dampers" and they come in various versions. They can be obtained either from the ventilation parts supplier you trust or simply on the relevant platforms.

Great, that's exactly what I was looking for. I will order some of them right away and try them out and then report back. Certainly, quite a few people have this problem. Then I can run the ventilation system much stronger at night when everyone is at home. At the moment, it is running completely contrary to the actual demand.

Great, that's exactly what I was looking for. I will order some of them right away

During installation, you should ensure that the filter/damper insert remains easy to replace.
I have 2 similar ones in use and after 3 months of operation, they are pitch-black from dust.
There could also be a risk of germ contamination if you don't clean them regularly.