Heat recovery from shower water - is it sensible?

room-wise demand-controlled ventilation

But in my opinion, this is an important point. Especially because of noise and the annoying overflow opening.

In my opinion, this is an important point. Especially because of the sound and the annoying overcurrent opening.

Sound: Do you mean the slot under the door by "sound" and the overcurrent opening slots above the windows (or somewhere else) to the outside in the decentralized ventilation system? I'm asking just to be sure as a "beginner"...

Sound: Do you mean by "sound" the gap under the door and by "overflow opening" slots above the windows (or somewhere else) to the outside in the decentralized ventilation system? I'm asking as a "beginner" just to be sure...

Any opening, whether at the top, bottom, or decentralized, so please plan supply and exhaust air by room. The house harmony will thank you.