“There’s no perfectly ‘safe’ level of ventilation because we don’t actually know what ‘safe’ is, since we don’t know how much exposure leads to transmission,” Angela Rasmussen, a Columbia University virologist,”
That is from an article recommended by a virologist studying airborne diseases. The result is predictable: Stay Home to remove the risk. If you want to get into the nuts and bolts and use HEPA filters, cleaning theater, and HVAC wizardry, read all of the interesting details. Then even if you can master the air in your indoor spaces, will you have the money, equipment, and expertise to do it? And there will be an environmental cost if you don’t recapture the energy with a heat recovery ventilator (HRV). I know many are willing to put our environment second to health, but that payment is coming due soon anyway too.
Saskboy's Abandoned Stuff 