adamzerner's Shortform

by adamzerner16th Dec 202024 comments
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I just learned some important things about indoor air quality after watching Why Air Quality Matters, a presentation by David Heinemeier Hanson, the creator of Ruby on Rails. It seems like something that is both important and under the radar, so I'll brain dump + summarize my takeaways here, but I encourage you to watch the whole thing.

  • He said he spent three weeks researching and experimenting with it full time. I place a pretty good amount of trust in his credibility here, based on a) my prior experiences with his work and b) him seeming like he did pretty thorough research.
  • It's easy for CO2 levels to build up. We breathe it out and if you're not getting circulation from fresh air, it'll accumulate.
  • This has pretty big impacts on your cognitive function. It seems similar to not getting enough sleep. Not getting enough sleep also has a pretty big impact on your cognitive function. And perhaps more importantly, it's something that we are prone to underestimating. It feels like we're only a little bit off, when in reality we're a lot off.
  • There are things called volatile organic compounds, aka VOCs. Those are really bad for your health. They come from a variety of sources. Cleaning products and sprays are one. Another is that new car smell, which you don't only get from new cars, you also get it from stuff like new couches.
  • In general, when there's new construction, VOCs will be emitted. That's what lead to DHH learning about this. He bought a new house. His wife got sick. It turned out the glue from the wood panels was emitting VOCs and making her sick.
  • People in the world of commercial construction know all about this. When a hotel is constructed, they'll wait eg. a whole month, passing up revenue, to let the VOC's fizzle out. But in the world of residential construction, for whatever reason it isn't something people know about.
  • If you want to measure stuff like CO2 and VOCs, professional products are expensive, consumer products are usually inaccurate, but Awair is consumer product for $150 that is good.
  • If you want to improve indoor air quality, air purifiers are where it's at. They do a good job of it. You could use filters on eg. your air conditioner and stuff, but in practice that doesn't really work. High quality filters make your AC much less effective. Low quality filters are, well, low quality.
  • Alen is the brand of air purifier that DHH recommended after testing four brands. I spend about 10-15 minutes researching it. Alen seems to have a great reputation. The Wirecutter doesn't recommend Alen seemingly because you could get similar quality for about half the price.
  • I decided to purchase the Alen BreatheSmart 75i today for $769. a) I find it very plausible that you could get similar quality for less money, but since this is about health and it is a long term purchase, I am happy to pay a premium. b) They claim they offer the industry's only lifetime warranty. For a long term purchase, I think that's important, if only due to what it signals.
  • I considered purchasing more than one. From their website it seemed like that's what they recommend. But after talking things through with the saleswoman, it didn't seem necessary. The product weighs about 20 pounds and is portable, so we could bring it to the bedroom to purify the bedroom before we go to sleep.
  • I currently live in a ~1000sqft apartment and was initially planning on purchasing the 45i instead of the 75i. The 45i is made for 800sqft and 75i 1300sqft. The saleswoman said it's moreso a matter of time than ability. The 45i will eventually purify larger spaces, it'll just take longer. That'd probably be fine for my purposes, but since this is a long term purchase and I don't know what the future holds, I'd rather play it safe.
  • The Alen BreatheSmart does have an air quality sensor, but I decided to purchase an Awair as well. a) The Alen doesn't detect CO2 levels. At first I was thinking that I don't really need a CO2 sensor, I could just open the window a few times a day. But ultimately I think that there is value in having the sensor in my office. It sends you a push notification if CO2 levels pass whatever threshold, and I think that'd be a solid step up from me relying on my judgement and presence of mind to open windows. b) My girlfriend has been getting a sore throat at night. I think it's because we've been using the heat more and the heat dries out the air. We used an air purifier last night, but I think it'd be useful to use the Awair to make sure we get the humidity level right. (We do have a Nest thermostat which detects humidity, but it's not in our bedroom.)
  • In general, I'm a believer that health and productivity are so important that on the order of hundreds of dollars it isn't worth trying to cut costs.
  • Air quality is something you have to pay attention to outside of your house as well. The presentation mentioned a study of coffee shops having poor air quality.
  • Older houses have a lot more draft so air quality wasn't as big a problem. But newer homes have less draft. This is good for cutting your electric bill, but bad for air quality.


  • Cooking gives off a significant amount of bad particles, especially if you have a gas stove.
  • You are supposed to turn your vent on about five minutes before you start cooking. Most people don't turn it on at all unless it smells.
  • Apartment kitchens often have vents that recycle air instead of bringing in fresh air, which isn't what you want.
  • If you're using a humidifier, use distilled/filtered water. If you use water from the sink it will add bad particles to the air.
  • I've found that random appliances like the dish washer and laundry machines increase VO2 and/or PM2.5 levels.

This has pretty big impacts on your cognitive function. It seems similar to not getting enough sleep. Not getting enough sleep also has a pretty big impact on your cognitive function. And perhaps more importantly, it's something that we are prone to underestimating. It feels like we're only a little bit off, when in reality we're a lot off.

It is my repeated experience in companies that well-ventilated rooms are selected by people as workplaces, and the unventilated ones then remain available for meetings. I seem to be more sensitive about this than most people, so I often notice that "this room makes me drowsy". (My colleagues usually insists that it is not so bad, and they have a good reason to do so... why would they risk that their current workplace will be instead selected as a new meeting room, and they get this unventilated place as a new workspace?)

I just ordered the Awair on Amazon. It can be returned through Jan. 31; I've just ordered it to play with it for a few days, and will probably return it. I have a few specific questions I plan to answer with it:

  • How much CO2 builds up in my bedroom at night, both when I'm alone and when my partner is over.
  • How much CO2 builds up in my office during the day?
  • How much do I need to crack the window in my bedroom in order to keep CO2 levels low throughout the night?
  • When CO2 builds up, how quickly does opening a window restore a lower level of CO2?

With the answers to those questions, I hope I can return the detector and just keep my windows open enough to prevent CO2 buildup without making the house too cold.

That sounds reasonable and I considered doing something similar. What convinced me to get it anyway is that in the long run, even if the marginal gains in productivity and wellness you get from owning the Awair vs your approach are tiny, even tiny gains add up to the point where the $150 seems like a great ROI.

Have you gotten yours yet? If so, what are the results? I found that the only issue in my house is that the bedroom can get to quite high levels of CO2 if the door and windows are shut. Opening a window solves the problem, but makes the room cold. However, it's more comfortable to sleep with extra blankets in a cold room, than with fewer blankets in a stuffy room. It improves sleep quality.

It would be interesting to experiment in the office with having a window open, even during winter. However, I worry that being cold would create problems.

My feeling is that "figure out how to crack a window if the room feels stuffy" is the actionable advice here. Unless $150 is chump change to you, I'm not sure it's really worth keeping a device around to monitor the air quality.

Yup I got it both the Awair and the Alen.

  • PM2.5 started off crazy high for me before I got the Alen. Using the Alen brings it to near zero.
  • VO2 and PM2.5 accumulates rather easily when I cook, although I do have a gas stove. Also random other things like the dishwasher cause it to go up. The Alen brings it back down in ~30 minutes maybe.
  • CO2 usually hovers around a 3/5 on the Awair if I don't have a window open. I'm finding it tricky to deal with this, because opening a window makes it cold. I'm pretty sure my apartment's HVAC system just recycles the current air rather than bringing in new air. I'm hoping to buy a house soon so I think ventilation is something I'm going to look for.
  • For me I don't actually notice the CO2 without the Awair telling me. I don't think I'd do a good job of remembering to crack a window or something without it.
  • I wonder if your house has better ventilation than mine if you're not getting issues with PM2.5. Could be if it's an older house or if your HVAC system does ventilation.

I see what you're saying about how the actual actions you should take seem pretty much the same regardless of whether you have the Awair or not. I agree that it's close, but I think that small differences do exist, and that those small differences will add up to a massively large ROI over time.

1) If it prompts you to crack a window before you would otherwise notice/remember to do so.

2) If something new is causing issues. For me I noticed that my humidifier was jacking up the PM2.5 levels and realized I need to get a new one. I also noticed that the dishwasher jacks it up so now I know to not be around while it's running. I would imagine that over time new things like this will pop up, eg. using a new cleaning product or candle.

3) Moving to a new home, remodeling or buying eg. new furniture could cause differences.

4) Unknown unknowns that could cause issues.

Suppose you value time spent in better air quality at $1/hr and that the product lasts 25 years. To break even, you'd need it to get you an extra six hours of good air quality each year. That's just two afternoons of my example #1, where you were sitting around and forgot to crack a window or something when the Awair would have sent you a push notification to do so. $1/hr seems low and I'd expect it to give a good amount more than six extra hours per year, so my impression is that the ROI would be really good.

I do live in an old house.

I get the same effects of spiking VOCs and PM2.5 running the stove and microwave. In my case, the spikes seem to last only as long as the appliance is running. This makes sense, since the higher the concentration, the faster it will diffuse out of the house. A rule to turn on the stove vent or crack a window while cooking could help, but it's not obvious to me that a few minutes per day of high VOC is something to worry about over the long term.

I note in this paper that "The chemical diversity of the VOC group is reflected in the diversity of the health effects that individual VOCs can cause, ranging from no known health effects of relatively inert VOCs to highly toxic effects of reactive VOCs." How do I know that the Awair is testing for the more toxic end of the spectrum? There are no serious guidelines for VOCs in general. How do I know that the Awair's "guidelines" are meaningful?

My bedroom has poor ventilation. Cracking a window seems to improve my sleep quality, which seems like the most important effect of all in the long run.

It sounds like the effect of CO2 itself on cognitive performance is questionable. However, bioeffluents - the carbonyls, alkyl alcohols, aromatic alcohols, ammonia, and mercaptans we breathe out - do seem to have an effect on cognition when the air's really poorly ventilated. But the levels in my house didn't even approach the levels at which researchers have found statistically significant cognitive effects. I'm wondering if the better sleep quality is due to the cooler air rather than the better ventilation.

I really doubt that the Awair will last 25 years. I'd guess more like 5. I can set a reminder on my phone to crack a window each night and morning if necessary, and maybe write a little note to tape next to the stove if I feel like it. If that doesn't do it in any particular instance, then I doubt that lack of a push notification is the root of the problem.

Hm, let's see how those assumptions you're using affect the numbers. If it lasts 5 years instead of 25 the breakeven would become 30 hours/year instead of 6. And if we say that the value of better air quality is $0.20/hr instead of $1/hr due to the uncertainty in the research you mention, we multiply by 5 again and get 150 hours/year. With those assumptions, it seems like it's probably not worth it. And more generally, after talking it through, I no longer see it as an obvious +ROI.

(Interesting how helpful it is to "put a number on it". I think I should do this a lot more than I currently do.)

However, for myself I still feel really good about the purchases. I put a higher value on the $/hr because I value health, mood and productivity more than others probably do, and because I'm fortunate enough to be doing well financially. I also really enjoy the peace of mind. Knowing what I know now, if I didn't have my Awair I would be worried about things screwing up my air quality without me knowing.

"It's not obvious" is a useful critique

I recall hearing "it's not obvious that X" a lot in the rationality community, particularly in Robin Hanson's writing.

Sometimes people make a claim without really explaining it. Actually, this happens a lot of times. Often times the claim is made implicitly. This is fine if that claim is obvious.

But if the claim isn't obvious, then that link in the chain is broken and the whole argument falls apart. Not that it's been proven wrong or anything, just that it needs work. You need to spend the time establishing that claim. That link in the chain. So then, it is useful in these situations to point out when a link in the chain isn't obvious when it was being presumed obvious. I am a fan of "it's not obvious that X".

Agreed, but in many contexts, one should strive to be clear to what extent "it's not obvious that X"  implies "I don't think X is true in the relevant context or margin".  Many arguments that involve this are about universality or distant extension of something that IS obvious in more normal circumstances.  

Robin Hanson generally does specify that he's saying X isn't obvious (and is quite likely false) in some extreme circumstances, and his commenters are ... not obviously understanding that.

Hm, I'm having a little trouble thinking about the distinction between X in the current context vs X universally. Do you have any examples?

Glad to hear you've noticed this from Hanson too and it's not just me.

I think you might have reversed your opening line?

Hm, I might be having a brain fart but I'm not seeing it. My point is that people will make an argument "A is true based on X, Y and Z", someone will point out "it's not obvious that Y", and that comment is useful because it leads to a discussion about whether Y is true.

Suggested title: If it's not obvious, then how do we know it's true?

Changed to "It's not obvious" is a useful critique.

Okay, I thought you intended to say "People claim 'it's obvious that X'" when X wasn't obvious. Your new title is more clear.

Gotcha. I appreciate you pointing it out. I'm glad to get the feedback that it initially wasn't clear, both for self-improvement purposes and for the more immediate purpose of improving the title.

(It's got me thinking about variable names in programming. There's something more elegant about being concise, but then again, humans are biased towards expecting short inferential distances, so I probably should err on the side of longer more descriptive variable names. And post title!)

There's a concept I want to think more about: gravy.

Turkey without gravy is good. But adding the gravy... that's like the cherry on top. It takes it from good to great. It's good without the gravy, but the gravy makes it even better.

An example of gravy from my life is starting a successful startup. It's something I want to do, but it is gravy. Even if I never succeed at it, I still have a great life. Eg. by default my life is, say, a 7/10, but succeeding at a startup would be so awesome it'd make it a 10/10. But instead of this happening, my brain pulls a trick: it says "You need to succeed at this. When you do I'll give allow you to feel normal, a 5/10 happiness. But along the way there, I'm going to make you feel 2/10."

Maybe I'm more extreme than average here, but I think that this is a human thing, not a me-thing. It seems to be the norm when people pursue hard goals for them to feel this way. The rule, not the exception.

Everyone hates spam calls. What if a politician campaigned to address little annoyances like this? Seems like it could be a low hanging fruit.

Depends on what you mean by "low-hanging fruit". I think there are lots of problems like this that seem net-negative, but it doesn't seem anywhere close to the most important thing I would recommend politicians to do.

By low-hanging fruit I mean 1) non-trivial boost in electability and 2) good effort-to-reward ratio relative to other things a politician can focus on.

I agree that there are other things that would be more impactful, but perhaps there is room to do those more impactful things along with smaller, less impactful things.

I don't think there IS much low-hanging fruit.  Seemingly-easy things are almost always more complicated, and the credit for deceptively-hard things skews the wrong way: promising and failing hurts a lot (didn't even do this little thing), promising and succeeding only helps a little (thanks, but what important things have you done?).

Much better, in politics, to fail at important topics and get credit for trying.

[+][comment deleted]1mo 2