Question to start a model

Hi everyone,
I would like to model a mechanical ventilation with Butterfly for this basement:

. Do I take into account the thickness of the walls?
. Can I set an absolute and / or relative humidity and see how the side walls behave? If they condense? As?

Thanks so much

Take your interior plan and extrude it! Your volume represents the air.

@MassimilianoBusnelli As I know, Butterfly has no function of setting relative humidity.