Installation of controlled residential ventilation - in the ceiling or outside?

With supply air in the floor, you have more work at the latest when laying the floor. And the bottle of cola should also be an argument!

That's true, our floor layers did indeed have extra work for milling out. However, it was limited and you don't do that every day. I would first deny that the milling of the holes caused a huge additional effort when laying the floor.

As a rule, I don't drink a bottle of cola next to my window.

That a huge additional effort arose when milling the holes during floor laying, I would initially deny.

I did not speak of a huge additional effort, but of "more work," especially if you are a "self-laying person." I assume that this should not be a problem for craftsmen.

I generally do not drink a bottle of cola next to my window.

Dear children, you would not believe the ideas they come up with!
But it does not have to be cola. Think, for example, of the bucket of water for cleaning, which can also be tipped over.

Ultimately, everyone must decide for themselves where they want the fresh air supply to go. As for me, I am very happy about the outlets in the floor. I would not have liked them in the wall.