3 ms·
A good deal is spent explaining rising CO2 levels in the atmosphere and the effects of CO2 on cognition, but it wasn't immediately obvious to me how indoor CO2
by awb 6y ago
A good deal is spent explaining rising CO2 levels in the atmosphere and the effects of CO2 on cognition, but it wasn't immediately obvious to me how indoor CO2 levels would be rising. Towards the end, here is their explanation:
> in steady state, indoor CO2 concentration is always at least as high as the outdoor concentration (as neither generation nor ventilation rate can be negative) and simply scales with the ratio of generation to ventilation. For reasonable values of G and Q for elementary school students (0.004 L/s per student) and classrooms (10 L/s per student), respectively, a ratio G/Q equates to 400 ppm (Persily, 2018; Persily & de Jonge, 2017). Under such assumptions, then, an outdoor CO2 concentration of 477 ppm (411 ppm as in 2019, plus a 66‐ppm urban enhancement) would equate to 877 ppm inside the classroom upon reaching equilibrium.
The equation and explanation can be found about 60% of the way down.
- formerly_proven 6y agoMost classrooms (at least here) aren't well-ventilated (windows are generally kept closed because of "draft" or alternatively "we aren't heating for the air force!", and buildings generally don't have AC/air exchange), CO2 levels are often far beyond 1000 ppm in classrooms anyway, which is obviously not good (there may be debate if going from 450 ppm to 600 pm leads to worse outcomes, but it's pretty obvious that nausea-inducing levels of CO2 and air so stale it feels like breathing water most definitely lead to worse outcomes).
- wiz21c 6y agoIf climate becomes warmer, then we'll open the windows more often :-)
- klipt 6y agoNot if you're running AC.
- grishka 6y agoI'm from a place where you only need AC one week per year so naturally no one has it except in cars, but I've heard that decent systems, especially central ones, don't recirculate the same air over and over again but take it from the outside.
- Tempest1981 6y agoCheck out HRVs: (air exchangers) https://www.popularmechanics.com/home/interior-projects/how-to/a149/1275121/ https://www.popularmechanics.com/home/interior-projects/how-...