Controlled residential ventilation manufacturer selection - How to approach?

Then the airflow is important and not so much the device. Volume in rooms results from the flow velocities and the connection of the valves. It is like with the fan, when it is small and fast it becomes louder than when it is big and slow.

The position of the valves doesn't fit at all for you, I would do it like this. There are also planning tools for that, for example from Zehnder.

Halmi, I would have liked to use the planning tool from Zehnder. Unfortunately, I can't get it as a private person. It wouldn't be a problem if I had a heating engineer here who still had capacity. I'm hanging in the air and time is running out.