41–50 of 126 posts
Ok, dumb idea time: suppose that everyone in an office sits on a chair that raises their body to X volts. At the same time a collector mesh is provided at each desk, at -X volts, but shielded so that you can't touch it and shock yourself. What X is large enough to ensure that all the virus particles you cough out end up at the collector? Is it possible to do this without electrocuting everyone?
UV-C lights that irradiate an air duct is literally the most surprising (and in retrospect obvious) thing I learnt today. Is this something a household HVAC could be upgraded to. Do HNers in areas that have air con think it's a "yeah people will want that" idea?
[1] http://www.uvresources.com/blog/the-ultraviolet-germicidal-i...
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I was thinking HEPA filtration may already cater for virus's, but with HEPA certification being .3 microns and the COVID-19 virus 0.12 microns, then it gets down to individual air conditioning systems. Some may use ionising in combination or UV. So I foresee a whole raft of legislation and requirements for office spaces ahead. Which will only help drive the work from home long-term as cheaper office space. But also h…
HEPA can filter sub-0.3-micron particles, and the effectiveness trends to be even higher than its performance at 0.3 microns.
Although it's not certificated, but it's often true from a practical standpoint, due to the physics of mechanical filtration in general. The reason of using 0.3-micron in certification, is because it's the point where HEPA filters are the least effective. 0.3 um is the most difficult size to filter. Effectiveness goes up at both ends.
The effectiveness of HEPA filters trend to follow a U-shaped curve [0]. Below 0.3 um, particles are captured by the diffusion mechanism. Above 0.3 um, particles are captured by the interception and impaction mechanism. Around 0.3 um, neither mechanism is effective, and efficiency reaches a minimum.
[0] https://en.wikipedia.org/wiki/File:Filteration_Collection_Me...
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Why bother to disinfect when you can ventilate? Air with pathogens out, fresh air without pathogens in. (Regarding herd immunity: you're aware that at the current rate of 55000 people per day, it would take 10 years to infect 60% of 320 million people? Nothing to say of the countless casualties that you would get in the process.)
(That's why in Silicon Valley large companies have "air consultants" measure the freshness twice per year and report the rate. I've talked to some.)
So my question stands on how and what to do to have more effective air circulation indoors, and what else we should do. And why is this conversation only happening several months into a lockdown. It's as if American government is falling down from learned helplessness.
Earlier quoted context omitted.
We make fun of medieval medicine but look at this shit! We're pretending that saying some magic words has an effect on a physical reality of disease spread! Who says that saying its airborne "has" to mean that certain procedures have to be adopted? That's not a rule of the universe, it's a rule that humans came up with and agreed upon and humans have the power to fix. We distilled down a set of physical principles in…
While I understand the frustration, the reality is we shouldn’t be making fun of either. Just because the end result of something is inarguably “stupid” does not mean that any of the things that went into it are “stupid.” To do the Hacker News thing and make a bad analogy to computer science topics in a totally irrelevant thread, this is how I view a lot of stuff people complain about these days (think JavaScript, or…
It seems the reasoning by officials is, "Yes, it's airborne, but there's not enough N95 masks for everyone so we don't want to cause panic or an N95 mask shortage for doctors and nurses by admitting it's airborne."
Not the first time we were lied to as part of this disaster: https://www.nytimes.com/2020/09/30/world/europe/ski-party-pa... Turns out the "don't close borders" advice was a cached thought related to a plague outbreak in India over 25 years ago, and welded in place by politics.
Not an expert on radio isotopes or spectrography or viruses.
Note: I know, radioactive virus at this point might freakout people a little.
UV-C lights that irradiate an air duct is literally the most surprising (and in retrospect obvious) thing I learnt today. Is this something a household HVAC could be upgraded to. Do HNers in areas that have air con think it's a "yeah people will want that" idea?
It isn't very practical, as long as you don't worry about getting the virus from the outside in, which would be an unusual thing to worry about for home owners. Just vent it out in the open air and not on people.
Terrible for energy efficiency
Earlier quoted context omitted.
While I understand the frustration, the reality is we shouldn’t be making fun of either. Just because the end result of something is inarguably “stupid” does not mean that any of the things that went into it are “stupid.” To do the Hacker News thing and make a bad analogy to computer science topics in a totally irrelevant thread, this is how I view a lot of stuff people complain about these days (think JavaScript, or…
The people who will die because we haven't told them how to protect themselves don't care.
UV-C lights that irradiate an air duct is literally the most surprising (and in retrospect obvious) thing I learnt today. Is this something a household HVAC could be upgraded to. Do HNers in areas that have air con think it's a "yeah people will want that" idea?
