That doesn't work. In particular in modern buildings there might be 600+ residents with very few apartments per floor. The vectors for spreading of air between

That doesn't work. In particular in modern buildings there might be 600+ residents with very few apartments per floor. The vectors for spreading of air between apartments can be varied. Internal, external, air intakes, communal infrastructure etc. How this relates to the unavoidable and highly pungent smell of weed I do not know