It depends a lot on the age and quality of the building and the weather, but that's in the ballpark. But it is indeed true that houses being too "tight" can be a problem -- commercial buildings are basically required to have forced ventilation though.@russ_watters is an HVAC engineer and if he has worked hospitals he would have first hand experience. Anyway there is a rigorous way to determine air turn over in a house or a building. If there were none you would asphyxiate due to CO2 buildup. More people more buildup. I cannot recall what russ said about this but total replacement of the domestic air volume is on the order of 4 hours. (Please correct me).
To be honest, I'm not quite sure what you're getting at with this post, but I can work with it: because you always have dirt/dust/pollen/whatever coming into your house and you and your pets are always shedding particles at a disturbingly high rate, the single most important factor in filtration effectiveness is airflow.The point is: the air is refreshed more or less constantly to achieve this goal.
Yes, for pharma too; duct and/or wall mounted:UV sterilization of air flow is a fact for hospitals. See the NIH link above.