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Big Ass Fan’s Clean Air System

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Re: Big Ass Fan’s Clean Air System

#91

Post by clairity »

petertodd wrote: post #59
Devils-Avocado wrote: post #52

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…

Scientific research has not found much evidence for transmission by touch, known in the literature as fomite transmission: "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. F…

yes, masks are not a panacea and are highly politicized. we need to stop focusing on them, and focus on (semi-)private social gatherings of friends and strangers (high heterogeneous mixing coefficients) where most of the community transmission is happening, rather than wearing masks on the street (or even in grocery stores) where transmission risks are practically non-existent but compliance is conspicuous (but ineffective).

Re: Big Ass Fan’s Clean Air System

#92

Post by trhway »

sargun wrote: post #61

I’m kind of surprised that the people who make those pods at offices haven’t gotten into this. Heat inactivation is shown to be effective at getting rid of sars-cov-2. Those little pod things could have a cleaning cycle where they heat up to 65C (~150F) for 15-30 minutes. Add a UV-C light during the cleanse cycle, and you’ve probably got most things. If I were a wework, I would be building these as a place for people…

> Those little pod things could have a cleaning cycle where they heat up to 65C (~150F) for 15-30 minutes.

can i stay inside of it and make it 180 at least (ready to sell my soul for 200), please :) 8 months without sauna, god, have mercy...

Re: Big Ass Fan’s Clean Air System

#94

Post by adrianN »

exo762 wrote: post #38
MertsA wrote: post #29

Earlier quoted context omitted.

Seems like they just reflect all the UV from the bulb up and are counting on the ceiling not reflecting a harmful amount. With the right ceiling material that could actually be a pretty good idea.

I wonder how one can test if the amount of UV light reflected from the surface is dangerous? Alternatively, determine what is the percentage of the UV light absorbed?

There are low cost armlets that change color when exposed to UV (they're supposed to tell you when you should get out of the sun). I imagine they would also work for UV-C.

Re: Big Ass Fan’s Clean Air System

#95

Post by adrianN »

Mengkudulangsat wrote: post #75

Slightly off topic; I've been reading about putting dispersal disinfectants like Tea Tree Oil [1] into ventilation shafts so they spread around the building. Works similar to O3, but is safe around people. I'm wondering what sort of concentrations these dispersals need to be to actually make a difference. [1] https://www.pathology.uwa.edu.au/research/microbiology/tea-t...

Essential oils in concentrations that are germicidal are definitely not safe around people for prolonged exposure.

Re: Big Ass Fan’s Clean Air System

#96

Post by femto »

I'll be interested to see the advertising associated with its Q4 2020 Australian release [1]. Anything sold in Australia that makes a claim relating to COVID-19 is counted as a Therapeutic Good and must be approved by Australia's TGA (which involves evidence base studies).

[1] https://www.bigassfans.com/faq/can-i-order-big-ass-fans-clea...

[2] https://www.tga.gov.au/media-release/warning-about-products-... when the release

Re: Big Ass Fan’s Clean Air System

#97

Post by Mengkudulangsat »

ipsum2 wrote: post #86
Mengkudulangsat wrote: post #75

Slightly off topic; I've been reading about putting dispersal disinfectants like Tea Tree Oil [1] into ventilation shafts so they spread around the building. Works similar to O3, but is safe around people. I'm wondering what sort of concentrations these dispersals need to be to actually make a difference. [1] https://www.pathology.uwa.edu.au/research/microbiology/tea-t...

your link mentions nothing about ventilation. vodka is also a good disinfectant, but you wouldn't want to necessarily aerosolize it and vent it through a building.

Here's a link for a case study on an oil rig. However, the illness was thought to be fungi-related, not viruses.

[1] https://www.germxit.com/wp-content/uploads/2015/06/CSOilRigC...

Re: Big Ass Fan’s Clean Air System

#98

Post by nurettin »

aaron695 wrote: post #28
nurettin wrote: post #25

Earlier quoted context omitted.

Circulating air is what got 20 or so people infected with covid because someone decided to sit in front of a ventilator at a cafe South Korea. The staff, all of whom wore masks didn't get infected. https://www.straitstimes.com/asia/east-asia/covid-19-outbrea...

Your link is the medias factoid about mask wearing. And this is the problem, no one is explaining first principals to you. You are probably thinking of this factoid in China about air conditioners and this diagram, which is not what we are talking about at all. (The evidence is downward air is what you want) https://www.businessinsider.com.au/how-restaurant-air-condit...

Fan blows to the ground and separates air from infectious constituents which stick to the ground like a ball of mud. Got it.

Re: Big Ass Fan’s Clean Air System

#99

Post by Craighead »

kylebenzle wrote: post #80
mdorazio wrote: post #77

I genuinely don't understand how this is supposed to work in a real-world environment. Let's say someone near a fan is infected with Covid and sneezes. The airflow from the fan would then immediately push covid-containing particles around the space and closer to other people than if there were no airflow at all. Is it really possible that their magic "ion" particles would counteract this negative aspect? I'm extremel…

It doesn't "work". The fact that it made it to the front page of HN bodes badly for this community that has been going down hill for a long time. It just one step above a text based Reddit at this point.

Woe is me

Re: Big Ass Fan’s Clean Air System

#100

Post by bluGill »

danans wrote: post #84
bluGill wrote: post #71

Earlier quoted context omitted.

There are several different designs, some there is a mix of streams. Most are sadly not particularly efficient overall, but still much better than leaving a window open.

Is it really an HRV if the air streams mix? [1] The primary function of an HRV is ventilation. Any air stream mixing would nullify that objective. 1. https://www.greenbuildingadvisor.com/article/misconceptions-...

There are a few different types. One type blows air out "across rocks" to warm them up, and then reverses the fan pulling air in "across the same rocks" I simplified a lot in the above, but the idea should be clear - there is some mixing of streams in this style.
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