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Installing air filters in classrooms has surprisingly large educational benefits (2020)

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Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#121

Earlier quoted context omitted.

Rising co2 levels I believe are nowhere near the differential inside vs outside when windows are closed. There’s lots of reason to believe that rising co2 specifically lowers cognitive performance - our brains work on o2 and our body actively works to expel co2 as a waste product - increasing co2 levels means the body has less O2 available and has to work harder on co2 expulsion for survival instead of powering the b…

This is not quite correct. 1) CO2 levels have risen from under 300PPM in 1860 to over 400PPM right now -- by around 150PPM -- with a rise of about 25PPM per decade for the past four decades. The difference in CO2 levels in my bedroom with windows open and closed is a couple hundred PPM (500-800ppm range in my bedroom, with windows open and closed, respectively). I can definitely feel a difference in performance if I…

Here’s what Claude says.

1. Direct effects on brain physiology: When CO2 levels rise in the blood (hypercapnia), it causes vasodilation of cerebral blood vessels. While this initially increases blood flow, sustained elevation disrupts the brain's normal pH balance, affecting neural function.

2. Acid-base imbalance: Elevated CO2 in the blood forms carbonic acid, decreasing blood pH. This acidosis affects enzyme function, neurotransmitter activity, and neuronal excitability throughout the brain.

3. Oxygen displacement: While not typically reaching dangerous levels in standard indoor environments, higher CO2 concentrations can slightly reduce oxygen availability to brain tissues in enclosed spaces.

4. Inflammatory responses: Research suggests prolonged exposure to elevated CO2 may trigger low-grade neuroinflammatory responses, potentially impairing cognitive processes.

5. Disruption of neurotransmitter systems: CO2-induced acidosis appears to affect several neurotransmitter systems, particularly GABA and glutamate, which are critical for cognitive functions like attention, memory, and decision-making.

Studies have shown measurable cognitive effects at CO2 concentrations as low as 1,000 ppm, with more significant impairment at 2,500+ ppm - levels commonly found in poorly ventilated meeting rooms, classrooms, and offices.

As for indoor vs outdoor:

> Rising atmospheric CO2 levels from global warming don't pose the same cognitive risks as elevated indoor CO2. While indoor environments can reach 1,000-5,000+ ppm, causing measurable cognitive decline through mechanisms like acid-base imbalance and neurotransmitter disruption, global atmospheric CO2 is only about 420 ppm. Even with projected increases to 500-1,000 ppm by 2100 in worst-case scenarios, these levels remain below thresholds for significant cognitive impairment. Our bodies can also better adapt to gradual atmospheric changes compared to rapid indoor CO2 accumulation, making climate change impacts the primary concern rather than direct cognitive effects.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#122

Earlier quoted context omitted.

only ycombinator would have a hard time with the concept of 'open the window' and instead expect a capital installment of $2B to retrofit classrooms

Do you think everyone lives in California where there's comfortable sunny temperatures and no rain 360 days a year? Classic ycombinator post

When I was in school we opened the windows to let "fresh air" in even at -20 C... not all day ofc but every day.

And rain? What's the problem with opening a window when it's raining? Only if there's a rain storm... and not even then, depending on wind direction.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#123

Earlier quoted context omitted.

I was under the impression that younger kids had stronger immune systems for that reason, which is why the common wisdom is to expose your kid to as much as possible when they're young, because it's easier for them to fight it off and later rely on resistance?

I guess it's a quibble over the meaning of 'stronger', but that seems overly pedantic. Let's get data. A good overview of the allergy situation is here: https://en.wikipedia.org/wiki/Hygiene_hypothesis Though that article goes into more about young human immune systems too. TLDR: Yeah ... it's complicated, but the evidence seems to, just maybe, lean towards more exposure being better. So, you're right, I think?

the impression I got from the article is that it's a somewhat unsolved problem. the article mentions an "old friends" hypothesis that suggests that it's not exposure to dangerous pathogens that's important in childhood, but exposure to benevolent ones. but yeah, you're right, it's semantics really. kids have a different kind of strength. I would actually suggest it's quite analogous to brain development. kids are more adaptive and I'd argue creative, but adults are more experienced.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#124

Earlier quoted context omitted.

Tangential, are there DIY methods of activated carbon? I got pellets, impregnated sheets and a packaged one for my air purifier, but I dont know when they are helping and when they are exhausted.

To tell when carbon filters are exhausted, the best way is to use an indoor VOC monitor. Air filter AC is specially prepared, so making your own DIY charcoal (while possible) isn't nearly as effective. You can mostly regenerate/desorb the carbon by heating it to 400F. Never use your regular oven though, not least of which because it reeks . Get a cheap toaster oven and disposable foil pans and do it outside, in a loc…

Can you share an Amazon product which is real air filter carbon? And an enclosure?

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#125

Earlier quoted context omitted.

To tell when carbon filters are exhausted, the best way is to use an indoor VOC monitor. Air filter AC is specially prepared, so making your own DIY charcoal (while possible) isn't nearly as effective. You can mostly regenerate/desorb the carbon by heating it to 400F. Never use your regular oven though, not least of which because it reeks . Get a cheap toaster oven and disposable foil pans and do it outside, in a loc…

Can you share an Amazon product which is real air filter carbon? And an enclosure?

Some of the stuff on Amazon sold for indoor marijuana growing is probably legit, and you can easily buy cylindrical cartridges and attach an axial fan.

Or you can buy from one of the most reliable e-commerce sites in the US:

https://www.mcmaster.com/product/3722T98

https://www.mcmaster.com/product/2169K16

You’re on your own as to buying the correct size.

For what it’s worth, the IKEA carbon filters are inexpensive and appear to be legit.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#126
post #92
post #39

Earlier quoted context omitted.

Critical thinking and skepticism are good, but much of what happens on HN is not that. Thinking critically includes, most of all, finding value - you need to think critically (and skeptically) to avoid assigning value to things that don't have it, but you must find value. The goal is to build knowledge - just like the study author needs to find knowledge among flawed data, you must find knowledge among flawed studies…

Science is a long game, it's not about sales where you need to sell right now. Extreme results will be attempted to be replicated, which in turn costs a lot of funding. That is money and time, sometimes a whole persons career. This money and time is taken directly away from funding other, potentially more worthy or more likely to be correct studies. There is no point of looking at every (flawed) study in the most pos…

Are there some examples of "non flawed" research that is getting ignored? Because (as a non-academic) I feel like I'm seeing the same HN attitude that OP describes. No study is good enough for HN. There are always nit pickers that come out of the woodwork. For every science article about some study or finding, the top comment is always a variation on: "This study is flawed because..." Almost without exception. Also, the standard is so high: A single flaw found is grounds for dismissing the whole study as flawed.

My guess is if you raise examples of "good science" the HN peanut gallery will jump in to point out the flaws in that science, too.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#127

Earlier quoted context omitted.

> but expecting test scores to improve dramatically like this is not realistic That seems like a problem for the reader, not a problem with the text. Why would the reader expect this? Is it the use of present tense in the title rather than past tense?

What do you mean? The article implies it from the title through the text. They hedge by saying “could” but like most articles in this vein it goes on to pivot around the outlier study.

Ah! I just skipped the article. The paper is much more straightforward.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#128
post #30
post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

Based on your comment, the effect could be larger as well as smaller. All research is met on HN by people who know better and will tell you why it's flawed. There isn't a greater collection of expertise in the history of the world than on HN. Edit: I meant to add: What value can we find in this research? It wasn't published as scripture, the perfect answer to all our problems. It's one study of some interesting event…

Installing air filters is an intervention that has a cost and thus needs to be verified and proven. You don't roll such a thing out on a broad scale based on "the effect could be large".

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#129
post #9

I'm all for installing air filters in classrooms for a number of reasons, but I also think the extreme results from this study aren't going to hold up to further research. From the paper: > To do so, I leverage a unique setting arising from the largest gas leak in United States history, whereby the offending gas company installed air filters in every classroom, office and common area for all schools within five miles…

Perhaps we shouldn’t need a large cohort study to give little humans the right to breathe as good as battery chickens.

Re: Installing air filters in classrooms has surprisingly large educational benefits (2020)

#130
post #128
post #30

Earlier quoted context omitted.

Based on your comment, the effect could be larger as well as smaller. All research is met on HN by people who know better and will tell you why it's flawed. There isn't a greater collection of expertise in the history of the world than on HN. Edit: I meant to add: What value can we find in this research? It wasn't published as scripture, the perfect answer to all our problems. It's one study of some interesting event…

Installing air filters is an intervention that has a cost and thus needs to be verified and proven. You don't roll such a thing out on a broad scale based on "the effect could be large".

I find it bonkers we have better regulation around growing battery chickens than growing kids.

You don’t need massive study to find out that kids don’t like suffocating in classrooms.

It’s a bit like mandating reversing cameras on cars. Study says economically they do not make sense, but not squishing your kids trumps that.

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