You may have come across the NASA clean air study and this 4 minute TED talk by Kamal Meattle, an Indian businessman and environmental activist. Short version: you need 4 Areca Palm plants per person to convert CO2 to O2 during the day, 6-8 snake plants per person to convert CO2 to O2 during the night, and then a devil's ivy to remove other chemicals from the air. He rattles off a list of measured impacts for working in an office building with an appropriate number of plants that also seem pretty convincing.
It's not clear why he didn't go with the ones that looked best on the NASA study, the Peace Lily (also recommended by Nicholas Angel) or the Chrysanthemum (also recommended by the Emperor of Japan). But this also the first place where I saw someone discussing the relevant conversion rate (i.e. three plants per person wouldn't be enough); the NASA study synopsis on Wikipedia, at least, only mentions number of plants per area and doesn't seem to take the leaf surface area of the plant into consideration. So one suspects he's taken cost and efficiency into account.
Curious, as this comment inspired me to go get a Peace Lily for my desk.
I work in an office, but sit by myself (nearest person is maybe 8 meters or so away from me). The plant sits maybe 10 centimeters away on my left.
Did Meattle focus specifically on those office environments where people sit closely together?
I mean, I will reap benefits from having the plant regardless, but now I wonder how much I benefit vs. getting more plants (which is doable).
One or two research groups have published work on carbon dioxide and cognition. The state of the published literature is confusing.
Here is one paper on the topic. The authors investigate a proprietary cognitive benchmark, and experimentally manipulate carbon dioxide levels (without affecting other measures of air quality). They find implausibly large effects from increased carbon dioxide concentrations.
If the reported effects are real and the suggested interpretation is correct, I think it would be a big deal. To put this in perspective, carbon dioxide concentrations in my room vary between 500 and 1500 ppm depending on whether I open the windows. The experiment reports on cognitive effects for moving from 600 and 1000 ppm, and finds significant effects compared to interindividual differences.
I haven't spent much time looking into this (maybe 30 minutes, and another 30 minutes to write this post). I expect that if we spent some time looking into indoor CO2 we could have a much better sense of what was going on, by some combination of better literature review, discussion with experts, looking into the benchmark they used, and just generally thinking about it.
So, here's a proposal:
Some clarifications:
(Thanks to Andrew Critch for mentioning these results to me and Jessica Taylor for lending me a CO2 monitor so that I could see variability in indoor CO2 levels. I apologize for deliberately not doing my homework on this post.)