None of those seem particularly concerning. We have a gas range, and 15 min past the end of cooking everything is fine. I must imagine that most people don't live right next to the freeway so they probably have even better air quality except during wildfire season.
This makes me wonder, for a truly travel-size solution (or just otherwise compact needs), if there's a viable alternative that directs filtered air at a sleeper's head? In other words, would the net effect be equivalent for one person (such that they're breathing more or less the same cleanness of air)?
I grasp that such an approach might draw unfiltered surrounding air along with the filtered stream of air, and imagine that it would likely be easily overwhelmed by a steady supply of exceptionally polluted air (wildfire smoke or simply a heavily polluted urban area), but I still would be interested in knowing if the compromise never overcomes a level of placebo effect, or if there's a point where it actually achieves measurable benefit (both in efficacy and portability—like a even more compact and directional version of the Corsi-Rosenthal computer fan solution.)
An air purifier is the best noise machine for me, much better than the white noise machines with the tinny speakers. Even the brown noise setting on those isn't nearly deep enough to let me sleep.
Yea, having it and using it at max just as I go to bed just makes me feel much better for the air I'll be breathing while sleeping. I also used to always fall asleep to some noise or music, so this is such a nice replacement
I bought a large soldering iron air purifier and it turns out to be great; it has a continuious speed selector, easy to replace filters, and very pleasant spectrum. I like it better than the air conditioner, which cycles on and off noisily.
Filters are included, as well as high quality fans, AC/DC converter and speed controller, and the portable/collapsible enclosure. It's really not that expensive vs trying to put together the parts yourself, and it's tested to work very well compared to other more expensive filters.
Those fans will not have sufficient static pressure to be useful. These makeshift purifiers may be great in a pinch (wildfire season and stores are all out), but far from the best.
This is indeed the "conventional wisdom," but if you do the math it turns out this is incorrect.
The trick is to use high-airflow MERV 13 filters (ideally 3M 1900, which has high pleat count and low resistance) instead of high-resistance HEPA filters, so axial PC fans can generate enough pressure.
Merv-13 means it filters at least 75% of the particles passing through it.
For a standalone air filter which is pushing the filtered air into the same room its drawing from, we can assume reasonably good mixing of the intake and exhaust air. Thus to be equivalent to a HEPA-filter it only needs 1/3rd more airflow... Which really isn't much.
This doesn't follow for a a fancier setup where you're taking dirty air and blowing it into a cleanroom or something... but that's not how we're typically using household air filters.
The linked PC-fan purifier has been tested and shown to purify air faster than the conventional alternatives, and are not makeshift, so I'm not sure what you are referring to.
From the specs it looks like they are probably closer to higher-static-pressure server fans, the CADR is a few hundred CFM and it pulls 30+ watts. And as with many of these designs, you can compensate for low pressure performance by increasing filter surface area... the greater the surface area the lower the pressure drop. Of course, the problem with this is you are just spending more money on filters, which is the expensive part.
this feels like a 'dose makes the poison' scenario. you're talking about maybe $10 of difference annually if both were run continuously. and that's only if you bought an inefficient air purifier - if you elected to use, for eg, four Arctic P14 PSTs in a CR box then that's maybe double the kWh. this ends up being a couple of bucks more annually for the added benefit of having better air quality
I have one in the bedroom. On low, I barely hear it during the day (extra ambient noise from outside) but at night the white-noise is subtle but effective. That said, I don't like "loud" white noise, just a quiet hum.
YSK on low you won't be getting much air cleaning power. All air purifiers are rated based on their top fan speed.
Housefresh, which is a criminally underrated review channel btw, recently did a comparison of PC fans for this purpose. The Thermalright TL-14C family came out strong in the "Silent" category, with the best ultra-quiet 24/7 fan speed performance. This comes at the cost of slightly worse max speed CADR vs the venerable Arctic P14.
The Austin Air HealthMate is great as a noise machine. Very loud. It’s a HEPA filter and lasts 5 years. Never seen any other that lasts that long, but you pay for it upfront. after-market replacements are $250-300 for another 5 years.
I have that machine. It seems better at filtering chemicals and VOCs but not great at filtering particulates. It gets rid of odors very well but my PM2.5 meter barely budges.
I have IQAir HyperHEPA filters, plus whole-house AprilAire HEPA filters on the HVAC equipment in the attic. I’m fine on particulates.
Where I need extra help is with VOCs in certain locations. Like, in or near bathrooms. Or the cat litter boxes. IQAir does sell their GC line for that, and we have a couple of those. But the activated carbon filter media is super expensive. And these things are huge. Like, bigger than a dorm refrigerator.
It just looks like fog, but it is smoke, and the sky has an unusual orange color. Smells and tastes like you are standing in the path of a campfire, but you can't move out of the way. It irritates your eyes and throat if you spend more than 20 mins out there. You can go inside, but if the building you are in is leaky, it will smell like smoke inside there too.
The actual fire was hundreds of miles away. You can try driving in any direction for hours and not be clear of the smoke. Still, compared to other areas, this is barely worth complaining about.
My allergies became generally better at all hours just from sleeping in super cleaned air.
Why? Reducing baseline inflammation perhapse? Maybe decreased inflammation during sleep helps too, improved breathing? idk. Whatever it is this organism seems to prefer it.
Even when exposed to allergens during the day the run up to sneezing is much slower or doesn't happen.
I grasp that such an approach might draw unfiltered surrounding air along with the filtered stream of air, and imagine that it would likely be easily overwhelmed by a steady supply of exceptionally polluted air (wildfire smoke or simply a heavily polluted urban area), but I still would be interested in knowing if the compromise never overcomes a level of placebo effect, or if there's a point where it actually achieves measurable benefit (both in efficacy and portability—like a even more compact and directional version of the Corsi-Rosenthal computer fan solution.)
I got one during Santa Cruz wildfires in 2020 and now the kids have a pavlovian reflex to sleep once that gets turned on.
Ikea makes an air-purifier table, which is a end-run around it being a useless box in the room when switched off.
It's fairly expensive, not as good as a purpose built one, but it blends into the average room pretty well.
The trick is to use high-airflow MERV 13 filters (ideally 3M 1900, which has high pleat count and low resistance) instead of high-resistance HEPA filters, so axial PC fans can generate enough pressure.
For a standalone air filter which is pushing the filtered air into the same room its drawing from, we can assume reasonably good mixing of the intake and exhaust air. Thus to be equivalent to a HEPA-filter it only needs 1/3rd more airflow... Which really isn't much.
This doesn't follow for a a fancier setup where you're taking dirty air and blowing it into a cleanroom or something... but that's not how we're typically using household air filters.
For cost over time, twice the filters means twice the replacement interval, so the additional filter cost cancels out.
For sleeping I prefer rain sounds though
I prefer having quiet air filters that I can run all day (based on air quality) instead of noisy ones I only use at night.
I still haven’t seen anything else that can compare to IQAir HyperHEPA filters. They use these things in hospitals.
Turning them up to med/high would just cause too much airflow.
I have one in the bedroom. On low, I barely hear it during the day (extra ambient noise from outside) but at night the white-noise is subtle but effective. That said, I don't like "loud" white noise, just a quiet hum.
Housefresh, which is a criminally underrated review channel btw, recently did a comparison of PC fans for this purpose. The Thermalright TL-14C family came out strong in the "Silent" category, with the best ultra-quiet 24/7 fan speed performance. This comes at the cost of slightly worse max speed CADR vs the venerable Arctic P14.
https://www.youtube.com/watch?v=Rlz37IdCcIE
Where I need extra help is with VOCs in certain locations. Like, in or near bathrooms. Or the cat litter boxes. IQAir does sell their GC line for that, and we have a couple of those. But the activated carbon filter media is super expensive. And these things are huge. Like, bigger than a dorm refrigerator.
So, I welcome an alternative that does VOCs well.
>removes smoke and infectious particles
Where do people live that they need to remove such things, 18th century London?
https://commons.wikimedia.org/wiki/File:Wildfire_smoke_Wyand...
It just looks like fog, but it is smoke, and the sky has an unusual orange color. Smells and tastes like you are standing in the path of a campfire, but you can't move out of the way. It irritates your eyes and throat if you spend more than 20 mins out there. You can go inside, but if the building you are in is leaky, it will smell like smoke inside there too.
The actual fire was hundreds of miles away. You can try driving in any direction for hours and not be clear of the smoke. Still, compared to other areas, this is barely worth complaining about.
SF Bay Area during the summer fires of a few years ago
Wind blows smoke around. There are currently fires in northern Michigan that are affecting the air quality in Chicago, which is 350+ miles away.
https://data.usatoday.com/fires/
My allergies became generally better at all hours just from sleeping in super cleaned air.
Why? Reducing baseline inflammation perhapse? Maybe decreased inflammation during sleep helps too, improved breathing? idk. Whatever it is this organism seems to prefer it.
Even when exposed to allergens during the day the run up to sneezing is much slower or doesn't happen.