Well, a ceiling fan producing laminar flow is very likely to limit the spread. Side fans and windows, unlikely. The have been a few good studies of airflow dyna

Well, a ceiling fan producing laminar flow is very likely to limit the spread. Side fans and windows, unlikely. The have been a few good studies of airflow dynamics. Ultimately the best cheapest defense building wise would be airflow over 12 CFM in a top to bottom way. This is essentially an air curtain strength. That's rather expensive and takes a lot of big fans or very strong HVAC system with many air outlets. Being outside only works as long as you can spread people out heavily enough. It's better than unventilated buildings, but the benefit is overshadowed by density or distance. (See: Florida beach policy and cases after the delay.)