16 ms·

Real-world data show that filters clean Covid-causing virus from air

244 points by bruceb 5y ago

peakaboo 5y ago
How are they going to make billions of profit from air filters?
- bradknowles 5y ago
  Have you looked at the prices of HEPA filter machines? Check out the cost of IQAir units.
  - cptskippy 5y ago
    Those are like the Louis Vuitton of air filters. I think most people can get by with a Winx air filter.
    - azinman2 5y ago
      I don’t want a hospital I’m in to “just get by”…
      - sudosysgen 5y ago
        The machine is mostly just a question of convenience, as long as the flow rate is right it's the filter that does all the work, and those are relatively much cheaper.
dmix 5y ago
> “This study suggests that HEPA air cleaners, which remain little-used in Canadian hospitals, What, they are "little used"? I'd assume that's the first place that would have adopted them. So strange how some hospitals operate.
- mmastrac 5y ago
  I suppose the cost of installation outweighed the minor inconvenience of colds and flus spreading in the past. Only now that we have a deadlier virus does it make sense.
  - trutannus 5y ago
    Most likely. Canada also has a habit of under-spending on healthcare in general. The system is also hypersensitive to political whims and can end up getting neglected as a result. This is because the provinces have direct control over every aspect of the healthcare system, and set the budget for them directly. Unlike other nations like Germany and Estonia, Canada's healthcare system is fully dependent on the provincial government to exist and be funded. If I'm not mistaken, in the two countries I mentioned, clinics can get private funding while providing universal access in most cases, which means they have a larger buffer between the political whims of the state, and their ability to provide service. If the state under-provides, the clinics can seek investors to cover the new costs, all the while maintaining universal coverage. That's not something Canadians can do. Talk of any private involvement, or restructuring in general, in Canada's healthcare system is often very politically charged and not particularly honest, so change is not happening any time soon. I suspect the issue here is that the hospitals know that having HEPA filters would be a good idea, but political will isn't there to give them what they need. Canadian politics on both sides lately has been more about the appearance of progress through large gestures, rather than careful consideration of long term solutions. It's very unfortunate.
    - jleyank 5y ago
      Have you lived any length of time in Canada? If so, where? While I have been fortunate enough to not have needed to go to hospital, my dental office reopened after the initial lockdown last year with a HEPA filter, doorway screen and other paraphernalia which made each workarea look like a clean room. And they shifted from water to air-driven cleaning and dressed like sci-fi actors. I would imagine the hospitals were similar due to the stress put upon them. Anecdotally, my wife had a breathing test in hospital a few days ago and they checked vaccination status and accepted the mask she walked in with. Given that the federal government is responsible for funding much/most of the provincial health care system, they have some input into how things operate. Most provinces have a good handle on covid unless their government went too deep into the "covid is over" bit (Alberta, Saskatchewan). The covid response here was delayed due to the need to secure vaccines from others, but the end result has been quite good. I have lived all over N America, and the freedom/flexibility of the Canadian health system has been better than anywhere except St. Louis, MO when I was there - and that required full-time employment.
jeeeb 5y ago
Here in Australia states have been been putting portable air filters in schools, age care homes and so on. Victoria for example ordered 51,000 filters recently to place across all schools.
dboreham 5y ago
Suspect that "These organisms are not typically thought to spread through the air" was not evidence-based.
- mythrwy 5y ago
  Is a virus actually considered an "organism"?
junon 5y ago
"COVID-causing virus" So.. COVID.
- umvi 5y ago
  HIV is to AIDS as SARS-CoV-2 is to COVID
  - est31 5y ago
    Not entirely. AIDS is only the name for the final stage of the disease, when your immune system is rendered totally unable to defend your body. It usually takes years from an HIV infection until AIDS develops. In the first viremic phase of HIV you can even have fever but often people don't notice it or put it off as some innocent cold. COVID-19 however is used however to refer to all stages and forms of the disease. https://en.wikipedia.org/wiki/HIV/AIDS#Acquired_immunodeficiency_syndrome https://en.wikipedia.org/wiki/HIV/AIDS#Acquired_immunodefici...
- _Microft 5y ago
  The disease that develops after being infected is called COVID-19 which means Corona Virus Disease (first seen in 20)19. The virus that causes it is SARS-CoV-2, the Severe Acute Respiratory Syndrom Corona Virus 2, which is one of many coronaviruses. The 2 is there because there was an earlier coronavirus caused disease (SARS) in 2002 for which the pathogen was called SARS-CoV(-1).
  - dragontamer 5y ago
    > which is one of many coronaviruses. There's only like 7 coronaviruses that have been discovered to infect a human. Three of which are SARS, MERS, and COVID19. Its pretty novel, all else considered.
    - weaksauce 5y ago
      I mean you are dropping the whole colds are coronaviruses too part though. though, the "cold" has a bunch of possible viruses that cause it (something like 200 different viruses) with the rhinovirus being one of the larger ways since it's so resistant to being inactivated comparatively to sars2 which only lasts for a day to three as a fomite vector, is neutralized by soap and water or 70% IPA. If covid had a viral vector like a rhinovirus that can last for months on surfaces in wide variety of conditions on surfaces and also spread via aerosolized particles it would have been a completely different pandemic that would have been far more deadly.
throwawayboise 5y ago
Not surprising? HEPA filters have been known to be able to filter viruses for some time; it's maybe the main reason they were invented? Not sure about that though.
- jpe90 5y ago
  It's not surprising if you understand how HEPA filters work, the particulate sizes that they're effective for, and the particulate sizes of viruses. Most people are not familiar with one or more of those things, so these stories are worth amplifying to the end of the earth and back, so that we can be better prepared to deal with this pandemic and the next.
- deleted 5y ago
  [deleted]
- spqr0a1 5y ago
  HEPA filters were developed for radioactive dust during the Manhattan Project. Only several years later did the technology get declassified and started being used in biology and medicine.
- auslegung 5y ago
  I have believed this for about a year, based on things I was reading at that time. I thought this was widely known because as you point out, that’s kinda their purpose. This article acknowledges that it was shown to be effective in lab settings and this is mainly about seeing those results in real life settings. But come on, if anyone finds something that’s probably effective based on science and isn’t going to negatively affect anyone, let’s shout it from the rooftops. If schools had been given funding to improve air circulation and filtration as well as a local gym now does after a $500,000 upgrade, I’m sure many would feel better about sending their children to school.
  - roughly 5y ago
    With the added bonus that it would be better for the students’ health generally and would likely improve overall educational outcomes. An awful lot of our handling of COVID has been farcical (a year and a half in, we’re still relying on cloth masks and obsessively sanitizing surfaces), but in the case of schools it’s veered toward absurdist/tragic.
throwaway984393 5y ago
You can build your own high-flow HEPA filter for about $45: 1x 20-inch box fan ($20) 1x 20x20 MERV-13+ MPR-2400+ HVAC air filter ($20) 1x roll of duct tape ($2.50) Air particle meters and other testing show they work just as well as big expensive machines (it's just the filter doing all the work). This is indeed a dirt cheap way to improve overall health.
- dragontamer 5y ago
  > 1x 20x20 MERV-13+ MPR-2400+ HVAC air filter ($20) That's a MERV-13 filter, not a HEPA filter. HEPA filters 99%+ of small (0.3um) particles per pass. A MERV-13 filter only filters like 60% per pass IIRC. That means that a 1000 cu. feet of air through the HEPA filter will result in 990+ cu. feet of clean air. While the MERV-13 filter will only produce 600 cu. feet of clean air. -------- A MERV13 filter would be good enough to improve most air, but its not HEPA and shouldn't be confused with it.
  - bsilvereagle 5y ago
    It’s worth noting that filter efficiency is a function of particulate size. A MERV13 and a HEPA filter are nearly equivalent for filtering pollen, but have drastically different performance for smoke and virus particles. There’s a plot 1/3 of the way down the page that shows the curves: https://frdmtoplay.com/nagivating-air-purification/ https://frdmtoplay.com/nagivating-air-purification/
    - dragontamer 5y ago
      Yeah, it's actually pretty complicated. MERV13 also needs less pressure, and a box fan is bad with pressure. If you stuck a HEPA filter on a box fan, it might only do 100cu feet of airflow. MERV13 is maybe 200. HEPA is designed for higher pressure centrifugal fans. MERV13 is likely the best balance for home made designs
      - hammock 5y ago
        There is a cubic design that people have been doing with HEPA filters (4 sides and a cardboard bottom) that solves the airflow issue.
b1gz1m 5y ago
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whiddershins 5y ago
Obviously. So what would’ve happened if we had created a zillion jobs installing air filtration to create healthier workplaces across many dimensions (not just Covid) instead of paying people to stay home?
- smiley1437 5y ago
  Do you have a time machine to bring this bit of information back in time? And, would anyone have believed you? Many things are obvious in hindsight.
  - proc0 5y ago
    Why didn't they research this earlier? "oops, we forgot?" Or "oops, nobody thought about it?" There have been videos going around many months ago of people in the business saying this is what should be doing instead of wearing masks. But hey, let's not doubt or question, that's bad!
  - AreYouSirius 5y ago
    no hindsight needed, why are all those millions of people wearing masks ? because WE ALL know filtration WORKS.
  - whiddershins 5y ago
    We had the information. It’s why we didn’t have huge outbreaks related to planes. Anyone who looked into this, including me, knew this more than a year ago.
- AreYouSirius 5y ago
  WRONG ! You are force to think this way ! BUT What if you asked hospital staff if those ventilation unit in ICUs do have filter inside or they just recycle indoor infected hospital air and just add clean oxygen ??? so basically if you get into hospital and they hook you up onto ventilation unit, you will increase virus load inside your lungs because all those viruses you exhale are not filtered and you will inhale them later. So just imagine how much is ventilation hookup in hospital good and how much is bad for you !!! not talking about HVAC, im talking about medical equipment directly pumping hospital air into your lungs.
dukeofdoom 5y ago
In Canada, Many school, and public buildings still have asbestos used throughout and very outdated ventilation systems. Schools in smaller towns were built in the 60s and 70s. Asbestos was a town in Quebec before they changed the name. Vaccines are pushed in part so hard, because its the cheapest solution for government to implement. Not building extra hospitals. Firing unvaccinated nurses, and hospital employees during a pandemic is the other government solution. This of course will blow back hard, should the vaccine efficiency wane over winter.
dukeofdoom 5y ago
So who makes a good room air filter? I have a dozen container ships go by, a few hundred meters away from my window a day.
- murgindrag 5y ago
  I was surprised by the quality of the Coway Airmega 200M. Good reviews, but looked sketchy: - Super-quiet - Sensor does actually speed it up with even trivial amounts of pollution. You sneeze in the same room, or spray some hairspray, and woosh. - Washable prefilter, carbon filter, HEPA filter I have a super-high-end air filter from 2-3 decades ago, and I'm surprised by the progress. The cheap 2020 unit is better.
- seanmcdirmid 5y ago
  A heavy duty Blue Air? I’d stay away from the 605 unless your problem is really bad, they are just too loud. The newer ones are nice and quiet, though the ones they target at the western markets are much so than the ones that sell well in China (where air pollution is much more of a problem). You might want to start with measuring your indoor air quality.
chmod600 5y ago
How effective would a mediocre filter be, just by physically bouncing the virus around? Is the virus fragile enough to be deateoyed that way?
DantesKite 5y ago
Wouldn’t be a bad idea to start having air filters in confined spaces. Elevators, gyms, restaurants. Not saying it has to happen all at once, but it would help decrease most respiratory diseases from spreading.
- jonnycomputer 5y ago
  classrooms
  - sschueller 5y ago
    Classrooms where already an issue before Covid. Concentration goes way down when the air starts to get thick and same goes for meeting rooms. How many times have you entered a meeting room where the air was so thick you felt it as soon as you stepped in?
- nradov 5y ago
  I'm skeptical that would be good for overall long term health. There are only a limited number of endemic respiratory viruses. Most of us will be exposed to them at multiple times in our lives regardless of what protective steps we take. So I'd rather get them while I'm still relatively young and healthy because the resulting immunity will give me at least partial protection later in life. Of course ideally it would be better to have effective sterilizing vaccines for all those various respiratory viruses, and perhaps someday we will. But those generally don't exist today for the vast majority of viruses.
  - noodlesUK 5y ago
    There are significant health benefits to cleaner air, not just from infectious disease, but also from particulate pollution and various other harmful substances. I strongly suspect that on the balance it would be a significant net positive from that aspect alone, though I don’t have possession of any hard evidence to back that up.
  - diebeforei485 5y ago
    It's pretty standard in all office buildings, well before the pandemic. I don't think expanding it to classrooms and gyms is going to cause problems.
nprz 5y ago
Someone made an interesting point that we got rid of cholera by drinking cleaner water and that we'll get rid of Covid by breathing cleaner air.
- felipellrocha 5y ago
  wut?
- drzaiusapelord 5y ago
  You won't often catch covid from stray particles but from the person breathing next to you, which these filters can't help. This study was in a hospital where everyone is wearing serious PPE, so its a super edge case to get rid of covid in the air because the main use case of catching covid has been handle by plain old PPE. This doesn't have sweeping applicability. It won't stop covid among the general population. Its for maybe hospitals that are on super covid lockdown that want a little more protection for their most vulnerable patients. We get rid of covid through mass vaccination like any other virus. There's no shortcuts for those who refuse masks and vaccines.
  - DonHopkins 5y ago
    >There's no shortcuts for those who refuse masks and vaccines. Just urns and gravestones.
    - user743 5y ago
      Or an immune system... or therapeutics...
      - DonHopkins 5y ago
        No horse parasites, or malaria, or places where the ultraviolet sun don't shine...
  - vondur 5y ago
    What if the air is being actively refreshed and filtered. I believe this is what needs to start happening in most indoor environments. This would definitely help with reducing the amount of cases.
DoingIsLearning 5y ago
> Hospitals have turned to portable air filters as an attractive solution when their isolation facilities are full. Woah! I knew that isolation rooms where full-on filtered and with positive pressure. But I genuinely believed that all hospital HVAC units and major circulation ducts had HEPA filter stages. Is this true? Is it not mandatory for hospitals to add these filtering stages on all HVAC units or circulation ducts? Do they really just keep rotating the same contaminated air throughout the whole hospital?
DonHopkins 5y ago
I recently posted a description of a powerful cooling fan I set up for my MacBook Pro that I'm thinking of adding a filter to. I wonder if the inline duct fan I got is strong enough for HEPA filters. It's a lot stronger than a box fan. It runs off of AC and has a speed adjustment control. The TD-500/150-160 moves 550 m^3/hour at 2480 rpm. https://www.solerpalau.com/nl-nl/ronde-buisventilator-td-silent-94-serie/ https://www.solerpalau.com/nl-nl/ronde-buisventilator-td-sil... https://statics.solerpalau.com/media/import/documentation/NL_TD-SILENT.pdf https://statics.solerpalau.com/media/import/documentation/NL... Here are some centrifugaal high pressure tube fans, but I don't know how noisy they are compared to the S&P "TD-SILENT" silent series (with noisy sounding names like "Cyclone"). https://www.ventilatieshop.com/buisventilatoren/hogedruk-buisventilator/ https://www.ventilatieshop.com/buisventilatoren/hogedruk-bui... https://news.ycombinator.com/item?id=28736187 https://news.ycombinator.com/item?id=28736187 The overheating problem on my MBP was so bad and so pathetically common, that I had to take drastic and expensive measures, which work pretty well. I tried various laptop cooling stands, and they were cheap and plastic and had shitty fans that hardly pushed any air, and didn't help. So I got a solid aluminum laptop stand without a fan, which conducts heat much better than plastic, and I bought four sets of stick-on heat sinks (some large and some small), and stuck them all over the back of the aluminum laptop stand on the surface that touches the bottom of the laptop. Then I bought a very powerful and quiet inline ventilation fan (the kind you use to pump air out of the bathroom), and analog speed dial (make sure you get an AC speed control for an AC fan, or a DC control if you get a DC fan) and some big wide round air tubing, and I set the fan in the opposite corner of the room (or outside the room with the door open) where the noise it generates is harder to hear, and ran the tube up to the cooling-fin encrusted back of the laptop stand, where it quietly blows lots of air on the back, and cools the stand and laptop quite effectively. I usually run it at the lowest quietest setting "1", but can turn it up to "10" to cool it down quicker when it's overheating. If anyone's interested I can provide links to the actual products I bought. Desktop and laptop fans were just not powerful enough, and very loud and clumsy, and it sucks to have the fan itself right next to you instead of in the next room. But the inline room ventilation fans are much more powerful and quieter and adjustable, but more expensive, and the flexible air tube lets you position the fan far away from the computer. I was losing so many hours of work due to overheating that it was well worth investing in all the equipment to really cool it down. Here are the small and large adhesive heat sinks, which are sold for 3d printers (I got two packs of each size: 16 eur total for 40 small ones, 16 eur total for 8 big ones): CTRICALVER Aluminium Heatsink, Black Heatsink, Thermal Adhesive Pad Cooler, for 3D Printer, Pack of 10 (20pcs) CTRICALVER Thermal conductivity of the radiator, heat conduction measures L40 mm x W40 mm x H11 mm, pack of 4 The fan was 185 eur, and the AC speed control was 35 eur or so, and I wired it myself with a switched plug for a couple euros. There are many models of fan, some AC and some DC, that move various amounts of air per minute, with fixed or three or variable speeds, that make different amounts of noise, but I shopped around and am pretty happy with the mid-range one I got. (S&P is a European brand so YYMV.) Soler & Palau TD-500/150-160 Silent 580/430m3 Air Conditioning Fan + REB-1N AC speed control The aluminum stand was 36 eur: NULAXY Laptop Ständer, Einstellbar Notebook Ständer, Ausblendbar laptopständer Kompatibel für alle 11-17 inches Notebooks: MacBook Pro/Air, Dell The next step I'm planning is making an air filteration system by taping together some filters like this DIY box fan air purifier, but using the powerful inline fan instead of a weak box fan: https://tombuildsstuff.blogspot.com/2013/06/better-box-fan-air-purifier.html https://tombuildsstuff.blogspot.com/2013/06/better-box-fan-a... I haven't decided what kind of filters to use yet: cheap high flow central air conditioner filters, or more expensive HEPA filters, that restrict the air flow more. The fan is quite powerful so I'm pretty sure it can handle the HEPA filters, but I haven't tried yet. Maybe that's overkill. But after wasting so many hours on overheating, overkill is kind of the point.
0xdeadb00f 5y ago
What's the deal with "covid-causing virus" in the title? Is there some kind of virus relationship ala HIV/AIDS that I wasn't aware of?
- Etherlord87 5y ago
  COVID-19 is the name of the disease caused by SARS-CoV-2 virus. https://en.wikipedia.org/wiki/COVID-19 https://en.wikipedia.org/wiki/COVID-19 https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndrome_coronavirus_2 https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr...
  - 0xdeadb00f 5y ago
    I can't believe I didn't know this. Thank you.
noipv4 5y ago
I bought a air filter which takes a rectangular panel filter like a Filtrete FAP series. Then I replace the filter regularly by cutting HEPA panel filters sold at Walmart to size. It's a cheap way to keep air clean at home. The amount of gunk and black soot and dust stuck within and to the filters is amazing. I also tend to run the device at full speed, the noise helps me tune out disturbances and leads to peaceful sleep.
aaronleather 5y ago
its a new term form the company to earn money at the name of air filtration to sell their products

244 points by bruceb 5y ago

peakaboo 5y ago

How are they going to make billions of profit from air filters?

bradknowles 5y ago
Have you looked at the prices of HEPA filter machines? Check out the cost of IQAir units.
- cptskippy 5y ago
  Those are like the Louis Vuitton of air filters. I think most people can get by with a Winx air filter.
  - azinman2 5y ago
    I don’t want a hospital I’m in to “just get by”…
    - sudosysgen 5y ago
      The machine is mostly just a question of convenience, as long as the flow rate is right it's the filter that does all the work, and those are relatively much cheaper.

dmix 5y ago

> “This study suggests that HEPA air cleaners, which remain little-used in Canadian hospitals, What, they are "little used"? I'd assume that's the first place that would have adopted them. So strange how some hospitals operate.

mmastrac 5y ago
I suppose the cost of installation outweighed the minor inconvenience of colds and flus spreading in the past. Only now that we have a deadlier virus does it make sense.
- trutannus 5y ago
  Most likely. Canada also has a habit of under-spending on healthcare in general. The system is also hypersensitive to political whims and can end up getting neglected as a result. This is because the provinces have direct control over every aspect of the healthcare system, and set the budget for them directly. Unlike other nations like Germany and Estonia, Canada's healthcare system is fully dependent on the provincial government to exist and be funded. If I'm not mistaken, in the two countries I mentioned, clinics can get private funding while providing universal access in most cases, which means they have a larger buffer between the political whims of the state, and their ability to provide service. If the state under-provides, the clinics can seek investors to cover the new costs, all the while maintaining universal coverage. That's not something Canadians can do. Talk of any private involvement, or restructuring in general, in Canada's healthcare system is often very politically charged and not particularly honest, so change is not happening any time soon. I suspect the issue here is that the hospitals know that having HEPA filters would be a good idea, but political will isn't there to give them what they need. Canadian politics on both sides lately has been more about the appearance of progress through large gestures, rather than careful consideration of long term solutions. It's very unfortunate.
  - jleyank 5y ago
    Have you lived any length of time in Canada? If so, where? While I have been fortunate enough to not have needed to go to hospital, my dental office reopened after the initial lockdown last year with a HEPA filter, doorway screen and other paraphernalia which made each workarea look like a clean room. And they shifted from water to air-driven cleaning and dressed like sci-fi actors. I would imagine the hospitals were similar due to the stress put upon them. Anecdotally, my wife had a breathing test in hospital a few days ago and they checked vaccination status and accepted the mask she walked in with. Given that the federal government is responsible for funding much/most of the provincial health care system, they have some input into how things operate. Most provinces have a good handle on covid unless their government went too deep into the "covid is over" bit (Alberta, Saskatchewan). The covid response here was delayed due to the need to secure vaccines from others, but the end result has been quite good. I have lived all over N America, and the freedom/flexibility of the Canadian health system has been better than anywhere except St. Louis, MO when I was there - and that required full-time employment.

jeeeb 5y ago

Here in Australia states have been been putting portable air filters in schools, age care homes and so on. Victoria for example ordered 51,000 filters recently to place across all schools.

dboreham 5y ago

Suspect that "These organisms are not typically thought to spread through the air" was not evidence-based.

mythrwy 5y ago
Is a virus actually considered an "organism"?

junon 5y ago

"COVID-causing virus" So.. COVID.

umvi 5y ago
HIV is to AIDS as SARS-CoV-2 is to COVID
- est31 5y ago
  Not entirely. AIDS is only the name for the final stage of the disease, when your immune system is rendered totally unable to defend your body. It usually takes years from an HIV infection until AIDS develops. In the first viremic phase of HIV you can even have fever but often people don't notice it or put it off as some innocent cold. COVID-19 however is used however to refer to all stages and forms of the disease. https://en.wikipedia.org/wiki/HIV/AIDS#Acquired_immunodeficiency_syndrome https://en.wikipedia.org/wiki/HIV/AIDS#Acquired_immunodefici...
_Microft 5y ago
The disease that develops after being infected is called COVID-19 which means Corona Virus Disease (first seen in 20)19. The virus that causes it is SARS-CoV-2, the Severe Acute Respiratory Syndrom Corona Virus 2, which is one of many coronaviruses. The 2 is there because there was an earlier coronavirus caused disease (SARS) in 2002 for which the pathogen was called SARS-CoV(-1).
- dragontamer 5y ago
  > which is one of many coronaviruses. There's only like 7 coronaviruses that have been discovered to infect a human. Three of which are SARS, MERS, and COVID19. Its pretty novel, all else considered.
  - weaksauce 5y ago
    I mean you are dropping the whole colds are coronaviruses too part though. though, the "cold" has a bunch of possible viruses that cause it (something like 200 different viruses) with the rhinovirus being one of the larger ways since it's so resistant to being inactivated comparatively to sars2 which only lasts for a day to three as a fomite vector, is neutralized by soap and water or 70% IPA. If covid had a viral vector like a rhinovirus that can last for months on surfaces in wide variety of conditions on surfaces and also spread via aerosolized particles it would have been a completely different pandemic that would have been far more deadly.

throwawayboise 5y ago

Not surprising? HEPA filters have been known to be able to filter viruses for some time; it's maybe the main reason they were invented? Not sure about that though.

jpe90 5y ago
It's not surprising if you understand how HEPA filters work, the particulate sizes that they're effective for, and the particulate sizes of viruses. Most people are not familiar with one or more of those things, so these stories are worth amplifying to the end of the earth and back, so that we can be better prepared to deal with this pandemic and the next.
deleted 5y ago
[deleted]
spqr0a1 5y ago
HEPA filters were developed for radioactive dust during the Manhattan Project. Only several years later did the technology get declassified and started being used in biology and medicine.
auslegung 5y ago
I have believed this for about a year, based on things I was reading at that time. I thought this was widely known because as you point out, that’s kinda their purpose. This article acknowledges that it was shown to be effective in lab settings and this is mainly about seeing those results in real life settings. But come on, if anyone finds something that’s probably effective based on science and isn’t going to negatively affect anyone, let’s shout it from the rooftops. If schools had been given funding to improve air circulation and filtration as well as a local gym now does after a $500,000 upgrade, I’m sure many would feel better about sending their children to school.
- roughly 5y ago
  With the added bonus that it would be better for the students’ health generally and would likely improve overall educational outcomes. An awful lot of our handling of COVID has been farcical (a year and a half in, we’re still relying on cloth masks and obsessively sanitizing surfaces), but in the case of schools it’s veered toward absurdist/tragic.

throwaway984393 5y ago

You can build your own high-flow HEPA filter for about $45: 1x 20-inch box fan ($20) 1x 20x20 MERV-13+ MPR-2400+ HVAC air filter ($20) 1x roll of duct tape ($2.50) Air particle meters and other testing show they work just as well as big expensive machines (it's just the filter doing all the work). This is indeed a dirt cheap way to improve overall health.

dragontamer 5y ago
> 1x 20x20 MERV-13+ MPR-2400+ HVAC air filter ($20) That's a MERV-13 filter, not a HEPA filter. HEPA filters 99%+ of small (0.3um) particles per pass. A MERV-13 filter only filters like 60% per pass IIRC. That means that a 1000 cu. feet of air through the HEPA filter will result in 990+ cu. feet of clean air. While the MERV-13 filter will only produce 600 cu. feet of clean air. -------- A MERV13 filter would be good enough to improve most air, but its not HEPA and shouldn't be confused with it.
- bsilvereagle 5y ago
  It’s worth noting that filter efficiency is a function of particulate size. A MERV13 and a HEPA filter are nearly equivalent for filtering pollen, but have drastically different performance for smoke and virus particles. There’s a plot 1/3 of the way down the page that shows the curves: https://frdmtoplay.com/nagivating-air-purification/ https://frdmtoplay.com/nagivating-air-purification/
  - dragontamer 5y ago
    Yeah, it's actually pretty complicated. MERV13 also needs less pressure, and a box fan is bad with pressure. If you stuck a HEPA filter on a box fan, it might only do 100cu feet of airflow. MERV13 is maybe 200. HEPA is designed for higher pressure centrifugal fans. MERV13 is likely the best balance for home made designs
    - hammock 5y ago
      There is a cubic design that people have been doing with HEPA filters (4 sides and a cardboard bottom) that solves the airflow issue.

b1gz1m 5y ago

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whiddershins 5y ago

Obviously. So what would’ve happened if we had created a zillion jobs installing air filtration to create healthier workplaces across many dimensions (not just Covid) instead of paying people to stay home?

smiley1437 5y ago
Do you have a time machine to bring this bit of information back in time? And, would anyone have believed you? Many things are obvious in hindsight.
- proc0 5y ago
  Why didn't they research this earlier? "oops, we forgot?" Or "oops, nobody thought about it?" There have been videos going around many months ago of people in the business saying this is what should be doing instead of wearing masks. But hey, let's not doubt or question, that's bad!
- AreYouSirius 5y ago
  no hindsight needed, why are all those millions of people wearing masks ? because WE ALL know filtration WORKS.
- whiddershins 5y ago
  We had the information. It’s why we didn’t have huge outbreaks related to planes. Anyone who looked into this, including me, knew this more than a year ago.
AreYouSirius 5y ago
WRONG ! You are force to think this way ! BUT What if you asked hospital staff if those ventilation unit in ICUs do have filter inside or they just recycle indoor infected hospital air and just add clean oxygen ??? so basically if you get into hospital and they hook you up onto ventilation unit, you will increase virus load inside your lungs because all those viruses you exhale are not filtered and you will inhale them later. So just imagine how much is ventilation hookup in hospital good and how much is bad for you !!! not talking about HVAC, im talking about medical equipment directly pumping hospital air into your lungs.

dukeofdoom 5y ago

In Canada, Many school, and public buildings still have asbestos used throughout and very outdated ventilation systems. Schools in smaller towns were built in the 60s and 70s. Asbestos was a town in Quebec before they changed the name. Vaccines are pushed in part so hard, because its the cheapest solution for government to implement. Not building extra hospitals. Firing unvaccinated nurses, and hospital employees during a pandemic is the other government solution. This of course will blow back hard, should the vaccine efficiency wane over winter.

dukeofdoom 5y ago

So who makes a good room air filter? I have a dozen container ships go by, a few hundred meters away from my window a day.

murgindrag 5y ago
I was surprised by the quality of the Coway Airmega 200M. Good reviews, but looked sketchy: - Super-quiet - Sensor does actually speed it up with even trivial amounts of pollution. You sneeze in the same room, or spray some hairspray, and woosh. - Washable prefilter, carbon filter, HEPA filter I have a super-high-end air filter from 2-3 decades ago, and I'm surprised by the progress. The cheap 2020 unit is better.
seanmcdirmid 5y ago
A heavy duty Blue Air? I’d stay away from the 605 unless your problem is really bad, they are just too loud. The newer ones are nice and quiet, though the ones they target at the western markets are much so than the ones that sell well in China (where air pollution is much more of a problem). You might want to start with measuring your indoor air quality.

chmod600 5y ago

How effective would a mediocre filter be, just by physically bouncing the virus around? Is the virus fragile enough to be deateoyed that way?

DantesKite 5y ago

Wouldn’t be a bad idea to start having air filters in confined spaces. Elevators, gyms, restaurants. Not saying it has to happen all at once, but it would help decrease most respiratory diseases from spreading.

jonnycomputer 5y ago
classrooms
- sschueller 5y ago
  Classrooms where already an issue before Covid. Concentration goes way down when the air starts to get thick and same goes for meeting rooms. How many times have you entered a meeting room where the air was so thick you felt it as soon as you stepped in?
nradov 5y ago
I'm skeptical that would be good for overall long term health. There are only a limited number of endemic respiratory viruses. Most of us will be exposed to them at multiple times in our lives regardless of what protective steps we take. So I'd rather get them while I'm still relatively young and healthy because the resulting immunity will give me at least partial protection later in life. Of course ideally it would be better to have effective sterilizing vaccines for all those various respiratory viruses, and perhaps someday we will. But those generally don't exist today for the vast majority of viruses.
- noodlesUK 5y ago
  There are significant health benefits to cleaner air, not just from infectious disease, but also from particulate pollution and various other harmful substances. I strongly suspect that on the balance it would be a significant net positive from that aspect alone, though I don’t have possession of any hard evidence to back that up.
- diebeforei485 5y ago
  It's pretty standard in all office buildings, well before the pandemic. I don't think expanding it to classrooms and gyms is going to cause problems.

nprz 5y ago

Someone made an interesting point that we got rid of cholera by drinking cleaner water and that we'll get rid of Covid by breathing cleaner air.

felipellrocha 5y ago
wut?
drzaiusapelord 5y ago
You won't often catch covid from stray particles but from the person breathing next to you, which these filters can't help. This study was in a hospital where everyone is wearing serious PPE, so its a super edge case to get rid of covid in the air because the main use case of catching covid has been handle by plain old PPE. This doesn't have sweeping applicability. It won't stop covid among the general population. Its for maybe hospitals that are on super covid lockdown that want a little more protection for their most vulnerable patients. We get rid of covid through mass vaccination like any other virus. There's no shortcuts for those who refuse masks and vaccines.
- DonHopkins 5y ago
  >There's no shortcuts for those who refuse masks and vaccines. Just urns and gravestones.
  - user743 5y ago
    Or an immune system... or therapeutics...
    - DonHopkins 5y ago
      No horse parasites, or malaria, or places where the ultraviolet sun don't shine...
- vondur 5y ago
  What if the air is being actively refreshed and filtered. I believe this is what needs to start happening in most indoor environments. This would definitely help with reducing the amount of cases.

DoingIsLearning 5y ago

> Hospitals have turned to portable air filters as an attractive solution when their isolation facilities are full. Woah! I knew that isolation rooms where full-on filtered and with positive pressure. But I genuinely believed that all hospital HVAC units and major circulation ducts had HEPA filter stages. Is this true? Is it not mandatory for hospitals to add these filtering stages on all HVAC units or circulation ducts? Do they really just keep rotating the same contaminated air throughout the whole hospital?

DonHopkins 5y ago

I recently posted a description of a powerful cooling fan I set up for my MacBook Pro that I'm thinking of adding a filter to. I wonder if the inline duct fan I got is strong enough for HEPA filters. It's a lot stronger than a box fan. It runs off of AC and has a speed adjustment control. The TD-500/150-160 moves 550 m^3/hour at 2480 rpm. https://www.solerpalau.com/nl-nl/ronde-buisventilator-td-silent-94-serie/ https://www.solerpalau.com/nl-nl/ronde-buisventilator-td-sil... https://statics.solerpalau.com/media/import/documentation/NL_TD-SILENT.pdf https://statics.solerpalau.com/media/import/documentation/NL... Here are some centrifugaal high pressure tube fans, but I don't know how noisy they are compared to the S&P "TD-SILENT" silent series (with noisy sounding names like "Cyclone"). https://www.ventilatieshop.com/buisventilatoren/hogedruk-buisventilator/ https://www.ventilatieshop.com/buisventilatoren/hogedruk-bui... https://news.ycombinator.com/item?id=28736187 https://news.ycombinator.com/item?id=28736187 The overheating problem on my MBP was so bad and so pathetically common, that I had to take drastic and expensive measures, which work pretty well. I tried various laptop cooling stands, and they were cheap and plastic and had shitty fans that hardly pushed any air, and didn't help. So I got a solid aluminum laptop stand without a fan, which conducts heat much better than plastic, and I bought four sets of stick-on heat sinks (some large and some small), and stuck them all over the back of the aluminum laptop stand on the surface that touches the bottom of the laptop. Then I bought a very powerful and quiet inline ventilation fan (the kind you use to pump air out of the bathroom), and analog speed dial (make sure you get an AC speed control for an AC fan, or a DC control if you get a DC fan) and some big wide round air tubing, and I set the fan in the opposite corner of the room (or outside the room with the door open) where the noise it generates is harder to hear, and ran the tube up to the cooling-fin encrusted back of the laptop stand, where it quietly blows lots of air on the back, and cools the stand and laptop quite effectively. I usually run it at the lowest quietest setting "1", but can turn it up to "10" to cool it down quicker when it's overheating. If anyone's interested I can provide links to the actual products I bought. Desktop and laptop fans were just not powerful enough, and very loud and clumsy, and it sucks to have the fan itself right next to you instead of in the next room. But the inline room ventilation fans are much more powerful and quieter and adjustable, but more expensive, and the flexible air tube lets you position the fan far away from the computer. I was losing so many hours of work due to overheating that it was well worth investing in all the equipment to really cool it down. Here are the small and large adhesive heat sinks, which are sold for 3d printers (I got two packs of each size: 16 eur total for 40 small ones, 16 eur total for 8 big ones): CTRICALVER Aluminium Heatsink, Black Heatsink, Thermal Adhesive Pad Cooler, for 3D Printer, Pack of 10 (20pcs) CTRICALVER Thermal conductivity of the radiator, heat conduction measures L40 mm x W40 mm x H11 mm, pack of 4 The fan was 185 eur, and the AC speed control was 35 eur or so, and I wired it myself with a switched plug for a couple euros. There are many models of fan, some AC and some DC, that move various amounts of air per minute, with fixed or three or variable speeds, that make different amounts of noise, but I shopped around and am pretty happy with the mid-range one I got. (S&P is a European brand so YYMV.) Soler & Palau TD-500/150-160 Silent 580/430m3 Air Conditioning Fan + REB-1N AC speed control The aluminum stand was 36 eur: NULAXY Laptop Ständer, Einstellbar Notebook Ständer, Ausblendbar laptopständer Kompatibel für alle 11-17 inches Notebooks: MacBook Pro/Air, Dell The next step I'm planning is making an air filteration system by taping together some filters like this DIY box fan air purifier, but using the powerful inline fan instead of a weak box fan: https://tombuildsstuff.blogspot.com/2013/06/better-box-fan-air-purifier.html https://tombuildsstuff.blogspot.com/2013/06/better-box-fan-a... I haven't decided what kind of filters to use yet: cheap high flow central air conditioner filters, or more expensive HEPA filters, that restrict the air flow more. The fan is quite powerful so I'm pretty sure it can handle the HEPA filters, but I haven't tried yet. Maybe that's overkill. But after wasting so many hours on overheating, overkill is kind of the point.

0xdeadb00f 5y ago

What's the deal with "covid-causing virus" in the title? Is there some kind of virus relationship ala HIV/AIDS that I wasn't aware of?

Etherlord87 5y ago
COVID-19 is the name of the disease caused by SARS-CoV-2 virus. https://en.wikipedia.org/wiki/COVID-19 https://en.wikipedia.org/wiki/COVID-19 https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndrome_coronavirus_2 https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndr...
- 0xdeadb00f 5y ago
  I can't believe I didn't know this. Thank you.

noipv4 5y ago

I bought a air filter which takes a rectangular panel filter like a Filtrete FAP series. Then I replace the filter regularly by cutting HEPA panel filters sold at Walmart to size. It's a cheap way to keep air clean at home. The amount of gunk and black soot and dust stuck within and to the filters is amazing. I also tend to run the device at full speed, the noise helps me tune out disturbances and leads to peaceful sleep.

aaronleather 5y ago

its a new term form the company to earn money at the name of air filtration to sell their products