i can recommend the CO2 monitor in the picture in that last boost. it's from Aranet4, the batteries last for months, and i've checked its readings against a properly calibrated professional CO2 monitor several times and it always agreed within 1%. now, it's quite possible that i lucked out with mine calibration wise - either way the *difference* in readings compared to outdoor baseline is what's meaningful

Jul 4, 2026, 16:03 UTCen

Replying to @adub@beige.party

imagine if i cancelled the remainder of every university class i taught once the CO2 level in the classroom rose to over 1000 ppm, on the basis of that study referred to in the boost. imagine if professors banded together, equipped ourselves with CO2 sensors, and we all did cancelled class time spent above 1000 ppm. then we would get better ventilation on campus. and the students would get better learning experiences!!

#CovidIsNotOver #Ventilation #MaskUpIndoors

Replying to @adub@beige.party

@adub

My blog at the time is very short, but links to two papers about CO2 and COVID.
statnews.com/2024/06/04/co2-ve

They note that it isn't just a great proxy for the air too close to be safe from infection...

...it turns out that CO2 is like an acid/base buffer and keeps the air chemistry friendly to COVID, it lasts much longer in the air, above 800.

Yes, COVID is no longer feared, but I can't imagine any reason that conclusion doesn't apply to colds and flu viruses.

edit: link just fixed

STATA new discovery about carbon dioxide is challenging decades-old ventilation doctrineCO2 is a good proxy for how much exhaled — and potentially infectious — air is in a room. New research suggests the more CO2 there is, the more virus-friendly the air becomes.