Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

First clean water, now clean air

finmoorhouse.com

Post reply on HN
Print view View original

141–149 of 149 posts

Re: First clean water, now clean air

#141

Post by schiffern »

Retric wrote: post #140
schiffern wrote: post #139

Earlier quoted context omitted.

Trust me, I know what vehicle exhaust smells like. ;) Living outside the city, I'm not constantly fatigued to its odors. So that's not a factor. But more to my original point, it disproves the "wind > location" idea (in my geography), since odor acts as a tracer for packets of air coming from the city. I wish I could calm your anxiety, but on the bright side I am truly touched by your outpouring of concern for my res…

You seem to misunderstand, Olfactory fatigue is very fast. When people fart for example the perception of smell goes away vastly sooner than the actual smell. If you’re trying to judge air concentrations based on how intense the smell, it simply doesn’t work.

I'm judging the presence of air pollutants. If I can smell it (ie above the lower detection limit), then I know I'm being exposed.

The converse is not necessarily true of course, but I can do this without hundreds of dollars in sensors. "Do what you can, where you are, with what you've got."

To account for sub-detectable pollution levels, I generally give myself a little extra buffer room. If I observe that detectable pollution odors begin at a certain point, I'll engage recirculate a half-mile before.

Generally nowadays I successfully avoid any detectable pollution/proxy odors, using the sort of preemptive planning I've described. You should try it!

---

TL;DR this whole thread: recirculate gives better air quality, just flush CO2 periodically, ideally when in relatively cleaner air

https://www.latimes.com/science/sciencenow/la-xpm-2013-sep-1...

https://news.ucr.edu/articles/2020/01/13/clearing-air-inside...

Re: First clean water, now clean air

#142

Post by Retric »

schiffern wrote: post #141
Retric wrote: post #140

Earlier quoted context omitted.

You seem to misunderstand, Olfactory fatigue is very fast. When people fart for example the perception of smell goes away vastly sooner than the actual smell. If you’re trying to judge air concentrations based on how intense the smell, it simply doesn’t work.

I'm judging the presence of air pollutants. If I can smell it (ie above the lower detection limit), then I know I'm being exposed. The converse is not necessarily true of course, but I can do this without hundreds of dollars in sensors. "Do what you can, where you are, with what you've got." To account for sub-detectable pollution levels, I generally give myself a little extra buffer room. If I observe that detectabl…

The converse is very much the problem.

Moving from constant levels of pollution to intermittent levels of population you notice ever stronger smells even as things improve. The reverse is also true, going from intermittent smells to constant toxicity it seems like things are improving.

This is the case because you most easily notice rapid changes not overall levels.

And again, both articles ignore the possibility of having better filters.

Re: First clean water, now clean air

#143

Post by schiffern »

Retric wrote: post #142
schiffern wrote: post #141

Earlier quoted context omitted.

I'm judging the presence of air pollutants. If I can smell it (ie above the lower detection limit), then I know I'm being exposed. The converse is not necessarily true of course, but I can do this without hundreds of dollars in sensors. "Do what you can, where you are, with what you've got." To account for sub-detectable pollution levels, I generally give myself a little extra buffer room. If I observe that detectabl…

The converse is very much the problem. Moving from constant levels of pollution to intermittent levels of population you notice ever stronger smells even as things improve. The reverse is also true, going from intermittent smells to constant toxicity it seems like things are improving. This is the case because you most easily notice rapid changes not overall levels. And again, both articles ignore the possibility of…

> The converse is very much the problem.

Not really. What I currently do prevents any health flare-ups, so it's working for me.

I might be effected by sub-detectable levels of pollution. I definitely would be effected by detectable levels of pollution. So I know I'm better off, which makes me happy.

I do not confuse this with perfection, but this level of cost/benefit tradeoff is "good enough" for me. Some of these tricks might be helpful for other people too!

> Moving from constant levels of pollution to intermittent levels of [pollution]

This is not my situation.

> And again, both articles ignore the possibility of having better filters.

I didn't write the articles, I just cited them to support the fact that recirculate results in lower pollution levels in cars.

I, in my life, very much do not ignore air filters. :)

Re: First clean water, now clean air

#144

Post by Retric »

schiffern wrote: post #143
Retric wrote: post #142

Earlier quoted context omitted.

The converse is very much the problem. Moving from constant levels of pollution to intermittent levels of population you notice ever stronger smells even as things improve. The reverse is also true, going from intermittent smells to constant toxicity it seems like things are improving. This is the case because you most easily notice rapid changes not overall levels. And again, both articles ignore the possibility of…

> The converse is very much the problem. Not really. What I currently do prevents any health flare-ups, so it's working for me. I might be effected by sub-detectable levels of pollution. I definitely would be effected by detectable levels of pollution. So I know I'm better off , which makes me happy. I do not confuse this with perfection, but this level of cost/benefit tradeoff is "good enough" for me. Some of these…

> recirculating results in lower pollution

Again, assuming inadequate filters, better filters invalidate their results.

> sub detectable

This is very much detectable, we just ignore it. Come back from a long trip to a remote enough area and it’s shocking how much everything smells, even small country roads briefly stink of pollution.

But, I think the dead horse has been beaten enough at this point.

Re: First clean water, now clean air

#145

Post by highmastdon »

giraffe_lady wrote: post #42
bsenftner wrote: post #23

Earlier quoted context omitted.

In Japan, it is common to see CO₂ monitor displays outside contained meeting spaces, such as theaters. My wife purchased an Aronet CO₂ monitor, and I took it with me on a business trip last week. The CO₂ while on the flight was in the 3000's range. The CO₂ at my client's office was in the mid 2000's range, as well as the hotel. Opening the hotel window the allowed 2 inches reduces CO₂ to the 600 range in 10 minutes,…

No, there won't be any battle. If there were going to it would have been during covid, with improved indoor ventilation being one of the major components of an in-depth mitigation strategy. There was no meaningful attempt or debate about changing ventilation standards then when it would have tangibly saved lives, there certainly won't be now.

Very cynical take: if there would’ve been a change in laws to increase ventilation, it would drastically reduce any illness, like flu, the common cold and other airborne viruses. This would lead to a decrease of taking vaccines for those, which would upset the big pharma.

Nearly any blanket-like measure was blocked by those. E.g. Vitamin-D supplementation, of which we know almost every indoor worker has a deficit of in western countries. Never ever was this prompted by govs even though there’s a clear correlation between deficit and deaths (not causation) and it has even antiviral properties (I suggest you to look into MedCram YouTube channel on videos around the first year of COVID where they go over many case studies on potential treatments)

Re: First clean water, now clean air

#146

Post by schiffern »

Retric wrote: post #144
schiffern wrote: post #143

Earlier quoted context omitted.

> The converse is very much the problem. Not really. What I currently do prevents any health flare-ups, so it's working for me. I might be effected by sub-detectable levels of pollution. I definitely would be effected by detectable levels of pollution. So I know I'm better off , which makes me happy. I do not confuse this with perfection, but this level of cost/benefit tradeoff is "good enough" for me. Some of these…

> recirculating results in lower pollution Again, assuming inadequate filters, better filters invalidate their results. > sub detectable This is very much detectable, we just ignore it. Come back from a long trip to a remote enough area and it’s shocking how much everything smells, even small country roads briefly stink of pollution. But, I think the dead horse has been beaten enough at this point.

> This is very much detectable, we just ignore it.

Nevertheless, sub-detectable levels we can ignore are lower than sub-detectable levels we can't ignore. So I'm still better off than I would be otherwise. How is this so hard to understand?

You're letting perfect be the enemy of good. This is the critical point you've been ignoring this whole time. All the horse beating could have been avoided! ;)

> recirculating results in lower pollution

Your "non particulate pollution" is just exhaled CO2. This is covered when I mention periodic flush of air. For obvious reasons, the editor inside me didn't feel the need to mention CO2 twice (especially not via muddy language like "non particulate pollution") in what is supposed to be a TLDR.

You should clarify, not obfuscate. Listening to your advice, it's confusing whether to prefer having recirculate on or off. You failed to clearly convey the most critical piece of information.

> better filters invalidate their results

"Better" is vague, so this advice is un-actionable.

Without citation I can only assume you just mean bioweapon defense mode, correct?

Re: First clean water, now clean air

#147

Post by Retric »

schiffern wrote: post #146
Retric wrote: post #144

Earlier quoted context omitted.

> recirculating results in lower pollution Again, assuming inadequate filters, better filters invalidate their results. > sub detectable This is very much detectable, we just ignore it. Come back from a long trip to a remote enough area and it’s shocking how much everything smells, even small country roads briefly stink of pollution. But, I think the dead horse has been beaten enough at this point.

> This is very much detectable, we just ignore it. Nevertheless, sub-detectable levels we can ignore are lower than sub-detectable levels we can't ignore . So I'm still better off than I would be otherwise. How is this so hard to understand? You're letting perfect be the enemy of good. This is the critical point you've been ignoring this whole time. All the horse beating could have been avoided! ;) > recirculating re…

There isn’t a level of smell you can’t quickly ignore.

> Your "non particulate pollution" is just exhaled CO2.

No, it’s carbon monoxide, NOx, SOx compounds etc. Opening your vents when you stop noticing smells makes things worse.

Re: First clean water, now clean air

#148

Post by schiffern »

Retric wrote: post #147
schiffern wrote: post #146

Earlier quoted context omitted.

> This is very much detectable, we just ignore it. Nevertheless, sub-detectable levels we can ignore are lower than sub-detectable levels we can't ignore . So I'm still better off than I would be otherwise. How is this so hard to understand? You're letting perfect be the enemy of good. This is the critical point you've been ignoring this whole time. All the horse beating could have been avoided! ;) > recirculating re…

There isn’t a level of smell you can’t quickly ignore. > Your "non particulate pollution" is just exhaled CO2. No, it’s carbon monoxide, NOx, SOx compounds etc. Opening your vents when you stop noticing smells makes things worse .

> There isn’t a level of smell you can’t quickly ignore.

Not a fixed level, of course! But at any given instant, the level you can ignore is lower than the one you can't. Hence I'm still better off doing this, a fact which apparently you can't stand for some weird reason...

You're also going to gather data over time, which will tend to smooth out any such day-to-day variations.

This is how you can reduce (not eliminate) pollution exposure without paying for expensive non-nose sensors. This is true whether you Believe It Or Not™.

>No, it’s carbon monoxide, NOx, SOx compounds etc.

Citation desperately needed. I showed you mine, you show me yours!

What conceivable mechanism could concentrate these traffic pollutants higher than the outside concentration? Are you running a pump that's somehow fighting entropy to push these outside traffic pollutants (against the alleged concentration gradient) into your car??

Usually it helps if your claim doesn't violate the laws of thermodynamics. :D

---

edit: I'll throw you a bone to save time. Literally the only way to achieve this outcome without violating physics is to intentionally reverse my recommendation: try to suck in only the most polluted urban air (intake the concentrated plume from a line of cars accelerating, behind a garbage truck or schoolbus, etc), and then switch to recirculate to save up that highly polluted air and breathe it for as long as possible.

So...... don't do that! If you're studying IAQ in cars, you need to control for that.

Re: First clean water, now clean air

#149

Post by blkhawk »

Retric wrote: post #72
blkhawk wrote: post #61

Earlier quoted context omitted.

I have had a self-build CO2 monitor for several years now and I find the airplane example Surprising. AFAIK the air in a Plane is cycled out too fast for that amount to develop. Maybe the Lower air pressure was the cause? Since it was portable it was probably the NIR type? If its not measuring all the time it might also be the heater type - I am really not sure how that type would deal with low pressure. Or was is th…

Local passenger density is going to play a role here venting air from low density first class areas isn’t going to do much. Similarly as you mention air flow is important as being in the middle of a large row could have vastly worse airflow than other areas. So, I could easily see the aircraft venting mostly 700ppm air while some areas hit 3000 ppm internally.

3000 ppm is directly breathing at the meter - at least with mine it is.
Post reply on HN