US buildings are designed to recirculate most air for energy cost reasons. Ventilation sounds like a good idea, but it doesn't match how things work today becau

US buildings are designed to recirculate most air for energy cost reasons. Ventilation sounds like a good idea, but it doesn't match how things work today because of how stale the air becomes. (That's why in Silicon Valley large companies have "air consultants" measure the freshness twice per year and report the rate. I've talked to some.) So my question stands on how and what to do to have more effective air circulation indoors, and what else we should do. And why is this conversation only happening several months into a lockdown. It's as if American government is falling down from learned helplessness.