Vertical air flow for events to reduce aerosol transmission

I was thinking about how to reduce the transmission of aerosol-transmitted diseases at events. It seems the thing to do is to get contaminated air out of horizontal space that is head height. As such, vertical airflow is required. Small holes in the floor to suck air downwards, or push in clean air. And likewise in the ceiling. Perhaps the air flow direction would depend on whether the air is being heated or cooled.