Pictured throughout thread are CO2 readings from my classroom Aranet4 CO2 meter. I have two 90-min classes (8:00-9:30, 9:40-11:10) & one 25-min homework/reading period (11:20-11:45) before lunch/prep from 11:50-1:15 & one 95-min class after (1:25-3:00). #covidco2 1/7

Maximum readings:

10-1: ~1200
10-2: ~1200
10-5: ~1200
10-6: 1447
10-7: 1345
10-8: 1446
10-9: 1448

Like ~80% of the rooms in my school, mine has no windows, but I'm lucky to have two doors, one opening to the hallway and one to our science lab. #covidco2 2/7

When I can keep both doors open, CO2 usually stays btwn 1000-1200, depending on the size of my class, which varies from 11 to 26.

I have 11 HS students in my AP Physics class & 16-26 6th-graders in my other 5 classes. My room volume is 215 m^3, & area 78.3 m^2. #covidco2 3/7

When I have to shut one or both doors to my room, CO2 climbs to btwn 1250-1450 ppm. If I were in one of the rooms w/no outlet (like most) CO2 would be higher. One of my rapscallion students breathed on the meter on 10-9. He was tarred & feathered for the infraction. #covidco2 4/7

All my efforts to convince school admin to improve ventilation (MERV 13 filters, more outside air, opening windows, air cleaners) have been for naught & such troublemaking likely earned me the ire of school admin & head custodian. Hygiene theater w/toxic cleaners prevails. 5/7

But I have 3 HEPA air cleaners in my room that collectively deliver about 900 CADR. $1000+ out of pocket but worth it. Thank you to the IAQ experts who've educated me on these issues, including @jljcolorado @CorsIAQ @jksmith34 @akm5376 @ShellyMBoulder @Poppendieck ...cont. 6/7

... @CathNoakes @kprather88 @linseymarr @JimRosenthal4 @j_g_allen & others I'm surely forgetting. Silver lining to the pandemic has been learning about the importance of IAQ & ventilation, which will enable me to create a better environment for my students now & in in future. 7/7