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Installing air filters in classrooms has large educational benefits?

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Re: Installing air filters in classrooms has large educational benefits?

#31

Post by derefr »

vkou wrote: post #26
jschwartzi wrote: post #11

Earlier quoted context omitted.

I've actually purchased a couple of indoor plants, a snake plant and a peace lily, to help generate oxygen indoors. I noticed the air "tasted" better about a week after I put them in the room. And I also noticed the air in my office feels better than the air in my apartment which has no plants. Whether that's something measurable I don't know, but while having these plants here I feel like I perform better.

To live, you need ~400L of O2/day. If you want your plants to provide even 10% of that number - 40L, your houseplants will need to take CO2 out of the air, store the carbon, and release the oxygen. This means that they will need to grow by ~300g - nearly a pound, a day , in order to produce 40L of oxygen. Unless your home is a wild, gymnasium-sized jungle, your houseplants aren't producing any measurable amounts of o…

And what should you do if your outside air has in it too much CO/methane/other small-molecule gas particles that HEPA filters have no hope of trapping?

Ignoring plants, there's gotta be some solution to this. What do they do to recycle the air up at the International Space Station?

Re: Installing air filters in classrooms has large educational benefits?

#32

Post by proee »

burfog wrote: post #20

At home it matters too. I recover faster from chest colds when I remember to keep the HEPA filter running. (instead of a simple speed knob, it boots up to a multilingual color display that I can't even dim, and of course the filter defaults to "off") Here is a common air quality problem. Anybody have ideas? My house is in a hot and humid area, so I run the air conditioning most of the year. The duct work appears to b…

Remove the material with mold from the space. Duct work is a terrible idea in humid climates. It's better to get those individual wall AC units per room. Mold is nasty stuff that will cause long term health problems.

Re: Installing air filters in classrooms has large educational benefits?

#34

Post by [deleted] »

Luc wrote: post #16
bobcostas55 wrote: post #6

Andrew Gelman: "No, I don’t think that this study offers good evidence that installing air filters in classrooms has surprisingly large educational benefits." https://statmodeling.stat.columbia.edu/2020/01/09/no-i-dont-...

This is so good! Gelman's comments on the study are a better HN post than this article. This is important stuff - you can already see people researching air filters in other comments, taking the supposed results of this study as settled truth.

[deleted]

Re: Installing air filters in classrooms has large educational benefits?

#35

Post by specialist »

burfog wrote: post #20

At home it matters too. I recover faster from chest colds when I remember to keep the HEPA filter running. (instead of a simple speed knob, it boots up to a multilingual color display that I can't even dim, and of course the filter defaults to "off") Here is a common air quality problem. Anybody have ideas? My house is in a hot and humid area, so I run the air conditioning most of the year. The duct work appears to b…

Maybe something like the wetandforget.com? It's active ingredient is alkyldimethylbenzyl ammonium chloride. https://en.wikipedia.org/wiki/Benzalkonium_chloride#Bioactiv...

FWIW, I removed the galvanized steel ducts from my house. The insides were disgusting, despite the professional vacuum service. My allergy symptoms and whatnot improved quite a bit afterwards.

Good luck. Please post whatever experiments you try.

Re: Installing air filters in classrooms has large educational benefits?

#36

Post by toomuchtodo »

proee wrote: post #32
burfog wrote: post #20

At home it matters too. I recover faster from chest colds when I remember to keep the HEPA filter running. (instead of a simple speed knob, it boots up to a multilingual color display that I can't even dim, and of course the filter defaults to "off") Here is a common air quality problem. Anybody have ideas? My house is in a hot and humid area, so I run the air conditioning most of the year. The duct work appears to b…

Remove the material with mold from the space. Duct work is a terrible idea in humid climates. It's better to get those individual wall AC units per room. Mold is nasty stuff that will cause long term health problems.

> It's better to get those individual wall AC units per room.

Ductless mini split units.

Re: Installing air filters in classrooms has large educational benefits?

#37

Post by vkou »

derefr wrote: post #31
vkou wrote: post #26

Earlier quoted context omitted.

To live, you need ~400L of O2/day. If you want your plants to provide even 10% of that number - 40L, your houseplants will need to take CO2 out of the air, store the carbon, and release the oxygen. This means that they will need to grow by ~300g - nearly a pound, a day , in order to produce 40L of oxygen. Unless your home is a wild, gymnasium-sized jungle, your houseplants aren't producing any measurable amounts of o…

And what should you do if your outside air has in it too much CO/methane/other small-molecule gas particles that HEPA filters have no hope of trapping? Ignoring plants, there's gotta be some solution to this. What do they do to recycle the air up at the International Space Station?

> And what should you do if your outside air has in it too much CO/methane/other small-molecule gas particles that HEPA filters have no hope of trapping?

You pack up, and move somewhere that's not the equivalent of sitting in the middle of a crude oil refinery.

Plants won't deal with these problems, either.

> What do they do to recycle the air up at the International Space Station?

For the most part, they chemically scrub the CO2 out[1], use the equivalents of catalytic converters to pull things like trace ammonia out of the air, and move on with life. There isn't a lot of heavy industry that happens inside the ISS.

If the air outside your window is literal poison, your house isn't sufficiently hermetically sealed for this to work.

[1] The actual process they use is the Sabatier process:

2H20 + E => 2H2 + O2

CO2 + 2H2 => CH4 + O2.

The water is brought up in resupply missions, the methane is vented into space. It's not a closed cycle (Which would require an enormous amount of plants), and its never going to have one, because it's going to be decommissioned in the next ~15 years.

Re: Installing air filters in classrooms has large educational benefits?

#38

Post by derefr »

vkou wrote: post #37
derefr wrote: post #31

Earlier quoted context omitted.

And what should you do if your outside air has in it too much CO/methane/other small-molecule gas particles that HEPA filters have no hope of trapping? Ignoring plants, there's gotta be some solution to this. What do they do to recycle the air up at the International Space Station?

> And what should you do if your outside air has in it too much CO/methane/other small-molecule gas particles that HEPA filters have no hope of trapping? You pack up, and move somewhere that's not the equivalent of sitting in the middle of a crude oil refinery. Plants won't deal with these problems, either. > What do they do to recycle the air up at the International Space Station? For the most part, they chemically…

> You pack up, and move somewhere that's not the equivalent of sitting in the middle of a crude oil refinery.

I would posit that for many people (e.g. citizens of China or India), "moving somewhere" where you're not constantly exposed to small-molecule pollutants would require more effort (e.g. acquiring a different citizenship) than would be required to atmospherically decouple your house.

Re: Installing air filters in classrooms has large educational benefits?

#39

Post by sundvor »

ajra wrote: post #23
sundvor wrote: post #15

Earlier quoted context omitted.

You could build your own with a Raspberry Pie and an sds011 sensor. Edit: Example @ https://aqicn.org/sensor/sds011/

Thanks! I have an unused Pi lying around so it's a great suggestion for me.

Nice! Cheers, I've ordered my own sensor and will be buying my own Pie as well. Will be a fun learning experience for me.

I realised I pasted the wrong link above, although still of interest. Anyway, here's a Pie specific article: https://www.raspberrypi.org/blog/monitor-air-quality-with-a-...

Re: Installing air filters in classrooms has large educational benefits?

#40

Post by rsanek »

derefr wrote: post #31
vkou wrote: post #26

Earlier quoted context omitted.

To live, you need ~400L of O2/day. If you want your plants to provide even 10% of that number - 40L, your houseplants will need to take CO2 out of the air, store the carbon, and release the oxygen. This means that they will need to grow by ~300g - nearly a pound, a day , in order to produce 40L of oxygen. Unless your home is a wild, gymnasium-sized jungle, your houseplants aren't producing any measurable amounts of o…

And what should you do if your outside air has in it too much CO/methane/other small-molecule gas particles that HEPA filters have no hope of trapping? Ignoring plants, there's gotta be some solution to this. What do they do to recycle the air up at the International Space Station?

The next step past HEPA (for consumers) is activated carbon/charcoal [0]. Most higher-end air purifiers have this included, which helps with filtering gases. I personally have an Airmega [1] and have been very happy with it. It was particularly helpful when there was smoke from fires in NorCal -- I had far better air quality at home than at the office.

[0] https://en.wikipedia.org/wiki/Carbon_filtering

[1] https://www.cowaymega.com/product/coway-airmega-400s-white/

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