Thread by @kprather88

The goal is to make sure aerosol counts are lower. We often use the analogy of cigarette smoke building up in poorly ventilated room as a visual analogy for being in a room with an infectious (speaking) supershedder. Lower counts = lower risk. CO2 alone won’t tell you this. 1/3

https://twitter.com/cappasnappa/status/1402348555600220172

Having lower PM in a room has many health benefits. People often focus only on CO2 but if you are in a room where it is difficult to increase ventilation, you have no choice but to add HEPA filtration. In this case, aerosol sensors (with size) are your only helpful metric. (2/3)

PM measurements tell you how effective your HEPA filtration is—shooting to be in upper left corner (see below). There is no question that avoiding the situation in the lower right corner lowers risk of infection. CO2 measurements alone cannot be used to assess this. (3/3)

https://twitter.com/kprather88/status/1402460593542496257

Another point that is being missed….Many people live in regions with horrible air quality so it is not helpful to open the window or pull in more “fresh air” thru HVAC. HEPA filters plus PM sensors can assure good indoor air quality. This is an environmental justice issue. (End)

#environmentaljustice we must think about other people as we come up with solutions to improve indoor air quality.