Thread: so in this thread I am posting my results from a "chamber study" at the rural school I described in my earlier thread. Different room, smaller, no air flow. I used a Dylos DC 1100 and a TSI CPC 3007. The CPC is a much better instrument - picks up nanometer particles. I basically used the smoke kits, 6 puffs, checked instruments after 10 seconds, wrote down "inlet" concentration and then put instruments on "clean" side of fan, about 1/2" from fan about 2 mins later. These are GRAB samples, so spot checks. Very quick and dirty!

So I worked with a local school, rural area, NO HVAC, to check out natural ventilation, and setting up box fan configurations and [box fan + 20"x 20" x 1" filter combos]

Smoke Test - before, minimal ventilation, 800 ft2 classroom via @YouTube I was really surprised with how the smoke just instantly rose just like those animations we have been seeing from aerosol scientists! We had a fan as an exhaust, so some air flow, but clearly not enough!

Thread: So I’m a Jill of All Trades Scientist - doer of many things and master of none. But I measure particles in air most times. I broke out a textbook Exposure Analysis by Ott, Steinmann, Wallace. A virus is a very tiny particle so what if we treated it as such? 1/ 2/ A tiny particle that weighs very little (an attogram according to Wikipedia 1 x 10^-18 of a gram) but still let’s assume the tiny mass is conserved (unlike particle number). With these and some “rule of thumb” or “back of the envelope” assumptions of the equation below: