51–60 of 110 posts
A german Max Planck institute is working on a DIY system for schools that will get rid of 90% of aerosols. It costs less than 200€ to build out of easily available parts. German link: https://www.mpic.de/4770837/eine-lueftungsanlage-fuer-schule...
But I think the more likely spread of COVID is from mundane surface transmissions. One of the 'mystery' COVID cases in New Zealand was eventually tracked to people touching the same elevator button about an hour apart, for example.
Same here in Europe - everyone is wearing masks, but how many times is the apartment entrance handle touched by people each day?
A german Max Planck institute is working on a DIY system for schools that will get rid of 90% of aerosols. It costs less than 200€ to build out of easily available parts. German link: https://www.mpic.de/4770837/eine-lueftungsanlage-fuer-schule...
You can achieve a clean air supply by opening another window in the classroom, but then you also let hot or cold air into the classroom (depending on the season), making the heating/cooling systems work even harder.
The answer to this is to run the exhaust/intake air channels through a heat recovery ventilator (HRV), which transfers energy from the hotter to colder airstream, while also introducing fresh air back to the space.
Airborne transmission of COVID is sexy, requiring solutions like this, and individual impositions like wearing masks which are easy to police. But I think the more likely spread of COVID is from mundane surface transmissions. One of the 'mystery' COVID cases in New Zealand was eventually tracked to people touching the same elevator button about an hour apart, for example. Same here in Europe - everyone is wearing mas…
A german Max Planck institute is working on a DIY system for schools that will get rid of 90% of aerosols. It costs less than 200€ to build out of easily available parts. German link: https://www.mpic.de/4770837/eine-lueftungsanlage-fuer-schule...
The question with that system is: where is the replacement air coming from? To be effective for disease particle controls, it needs to come from outside, otherwise you'd just be sucking dirty air from the rest of the building into the classroom - or even worse: backdrafting CO2 and CO from any combustion appliances within the building envelope. You can achieve a clean air supply by opening another window in the class…
Can someone please point me to actual studies validating the "ion" generation stuff? My dad insists that a wearable ion generator he bought works "because it's made by NASA" (it's not) but I can't find studies that validate the technology. Thanks in advance!
Airborne transmission of COVID is sexy, requiring solutions like this, and individual impositions like wearing masks which are easy to police. But I think the more likely spread of COVID is from mundane surface transmissions. One of the 'mystery' COVID cases in New Zealand was eventually tracked to people touching the same elevator button about an hour apart, for example. Same here in Europe - everyone is wearing mas…
"The principal mode by which people are infected with SARS-CoV-2 (the virus that causes COVID-19) is through exposure to respiratory droplets carrying infectious virus."
-https://www.thelancet.com/journals/laninf/article/PIIS1473-3...
You see this in the guidance by major health organizations. For instance the WHO clearly says:
"Current evidence suggests that the main way the virus spreads is by respiratory droplets among people who are in close contact with each other."
It probably can happen. But contact tracing hasn't found much evidence for it: the majority of infections can be explained by close contact from an infected person.
Re: masks, surgical masks and cloth mask far from 100% effective against small particles, with filtering efficiencies of 50% or less common though the fabric. Filtration is even less when you take into account air that bypasses the mask (the reason why your glasses fog up is because of air that isn't being filtered).
Also, very large numbers of people use them incorrectly, eg by leaving the nose uncovered, and leaving gaps. I don't think this is a matter of education: people know what correct wear is, and don't do it because it's much easier to breath if you defeat the mask's filtration.
Most people aren't wearing masks around family and friends anyway.
Can someone please point me to actual studies validating the "ion" generation stuff? My dad insists that a wearable ion generator he bought works "because it's made by NASA" (it's not) but I can't find studies that validate the technology. Thanks in advance!
Veratasium dug into it in quite a bit of depth. TL;DR: It doesn't do much (if any good). Worth watching, regardless. https://youtu.be/ZQ--scjcAZ4
But for air filtration, properly working negative ion generators certainly cause particles to leave the air: https://www.youtube.com/watch?v=y7QFJgTjzcc
The thing is, that means they end up on surfaces near the ion generator. That isn't necessarily a good thing. Proper HEPA filters are more likely to be what you want, as they remove particles entirely, putting them in a filter that can be disposed of.