Where to install the ventilation hose for controlled residential ventilation?

Very often they come into the concrete ceiling!

As already said at the beginning, you can do it either way. I also find the variant on the raw floor in the insulation level more practical. I would only suspend it if there is absolutely no other way.

It is cheaper in concrete. Less effort and the pipes are cheaper. If you adhere to the specified pipe distances, there are no problems with the statics. No impact sound insulation is lost either.

Ours were placed on the filigree ceiling and then cast with concrete.

That's how we have it too, perfect!

Ours were placed on the filigree ceiling and then poured with concrete.

us too