4 ms·

Infected after 5 minutes, from 20 feet away: Coronavirus’ spread indoors

adamjb 6y ago
Nice concise write up of the same study here: https://zeynep.substack.com/p/small-data-big-implications https://zeynep.substack.com/p/small-data-big-implications discussion: https://news.ycombinator.com/item?id=25305573 https://news.ycombinator.com/item?id=25305573
rajup 6y ago
Non-paywalled link: https://archive.is/gLkDt https://archive.is/gLkDt
antisthenes 6y ago
People always underestimate how hard indoor air quality is. Vast majority only concern themselves with the temperature, whereas you want to at least consider CO2 levels, humidity and particle quantity (dustiness). You also want to consider the direction in which the air moves when it gets returned to the HVAC unit, and where it comes back in later, and the level of filtration vs air flow. And you might have to retrofit all of that into an old shoddy building.
- porknubbins 6y ago
  Once I started measuring all those things in my old apartment I realized that and now only want to live in a newer space with forced air and a humidifier. Currently we have retrofit 2 ACs, 3 humidifiers and an air cleaner with HEPA filter.
  - copperx 6y ago
    How did you measure all these parameters?
    - pbadg3r 6y ago
      There are lots of ~$150 meters on Amazon. (e.g. https://www.amazon.com/GZAIR-Temperature-Relative-Humidity-0-9999ppm/dp/B0829ZWQVP/ https://www.amazon.com/GZAIR-Temperature-Relative-Humidity-0...) I've used some of these meters and the quality you can get for $150 is surprising! I've basically just held meters near filters, windows, and fans to understand air quality.
oftenwrong 6y ago
The idea that they are conducting in-depth investigations into individual cases of unexplained transmission shows an impressive level of commitment to contact tracing and research. >Contact tracers turned to the country’s Epidemic Investigation Support System, a digital platform introduced in South Korea amid the pandemic that allows investigators to access cellphone location information and credit card data of infected individuals in as little as 10 minutes. (privacy nightmare, but at least it is being used for good) >CCTV recordings showed the two never spoke, or touched any surfaces in common — door handles, cups or cutlery. From the sway of a light fixture, he could tell the air conditioning unit in the ceiling was on at the time. >Lee and his team re-created the conditions in the restaurant — researchers sat at tables as stand-ins — and measured the airflow. The high school student and a third diner who was infected had been sitting directly along the flow of air from an air conditioner; other diners who had their back to the airflow were not infected. Through genome sequencing, the team confirmed the three patients’ virus genomic types matched.

Nice concise write up of the same study here: https://zeynep.substack.com/p/small-data-big-implications https://zeynep.substack.com/p/small-data-big-implications discussion: https://news.ycombinator.com/item?id=25305573 https://news.ycombinator.com/item?id=25305573

rajup 6y ago

Non-paywalled link: https://archive.is/gLkDt https://archive.is/gLkDt

antisthenes 6y ago

People always underestimate how hard indoor air quality is. Vast majority only concern themselves with the temperature, whereas you want to at least consider CO2 levels, humidity and particle quantity (dustiness). You also want to consider the direction in which the air moves when it gets returned to the HVAC unit, and where it comes back in later, and the level of filtration vs air flow. And you might have to retrofit all of that into an old shoddy building.

porknubbins 6y ago
Once I started measuring all those things in my old apartment I realized that and now only want to live in a newer space with forced air and a humidifier. Currently we have retrofit 2 ACs, 3 humidifiers and an air cleaner with HEPA filter.
- copperx 6y ago
  How did you measure all these parameters?
  - pbadg3r 6y ago
    There are lots of ~$150 meters on Amazon. (e.g. https://www.amazon.com/GZAIR-Temperature-Relative-Humidity-0-9999ppm/dp/B0829ZWQVP/ https://www.amazon.com/GZAIR-Temperature-Relative-Humidity-0...) I've used some of these meters and the quality you can get for $150 is surprising! I've basically just held meters near filters, windows, and fans to understand air quality.

oftenwrong 6y ago

The idea that they are conducting in-depth investigations into individual cases of unexplained transmission shows an impressive level of commitment to contact tracing and research. >Contact tracers turned to the country’s Epidemic Investigation Support System, a digital platform introduced in South Korea amid the pandemic that allows investigators to access cellphone location information and credit card data of infected individuals in as little as 10 minutes. (privacy nightmare, but at least it is being used for good) >CCTV recordings showed the two never spoke, or touched any surfaces in common — door handles, cups or cutlery. From the sway of a light fixture, he could tell the air conditioning unit in the ceiling was on at the time. >Lee and his team re-created the conditions in the restaurant — researchers sat at tables as stand-ins — and measured the airflow. The high school student and a third diner who was infected had been sitting directly along the flow of air from an air conditioner; other diners who had their back to the airflow were not infected. Through genome sequencing, the team confirmed the three patients’ virus genomic types matched.