Shelly Miller, PhD. (2020, December 8). And here is an example calculation showing the difference in indoor virus concentrations with 3 vs. 6 ACH room ventilation when a person shedding the virus hangs out for an hour in that space https://t.co/p7M3boIh2w [Tweet]. @ShellyMBoulder. https://twitter.com/ShellyMBoulder/status/1336410448342736899