We are working on a project and are confused about the ventilation. It is an apartment building with studios in it. We chose for decentral ventilation system D. Now what I was wondering, is it enough to place these in the kitchen area hidden under a false ceiling attached to the outter wall? Or do we still need to place any type of tubes? And what about the bathrooms ? I attached our plan as a pdf. I hope you guys can help me and my team out!