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Richard Corsi, PhD, PE (Texas)
18.5K posts
Dean of Engineering, University of California, Davis
Indoor Environmental Engineer
Proud UC Davis Alumnus
Faith in younger generations
Dog lover
- On SW flight from DC to St Louis. Maybe 8 total masked out of 100+. A lot, and I mean a lot, of coughing and sniffling around me. Wonder how many tested today before boarding. I did. We reduce spread of this pandemic by doing whatever we can to be responsible citizens.
- Vaccinations are very important. Anti-virals are very important. They save lives. But this pandemic is not going anywhere until we get serious about lowering inhalation dose, folks. Doing so is not rocket science. It's techncially simple & just a matter of human will.
- Tears. I never wanted to make a cent off anything assoc w/ the #CorsiRosenthalBox. Today I received a letter from a child at a Montessori school. In it she thanked me for keeping her & her friends safe from COVID & added that she & her friends built more. What a payment! 🥲
- 1/ SARS-CoV-2 travels in aerosol particles emitted from an infected individual. You want to reduce the amount of these particles you breathe (lower inhalation dose is important). We know from decades of research that the following lower your inhalation dose of aerosol particles.
- 1/ Inhalation Dose It's been about inhalation dose from day 1. We have not kept our eye on the ball. Critical pre-vaccination. Critical post-vaccination. Been writing & speaking about this for nearly 20 mos. Reducing inhalation dose is a must. Come on folks, just do it!
- 1/ The #CorsiRosenthalBox (CR-Box) was intended as an open source, highly effective & cost-accessible air cleaner. Thrilled it has succeeded on all fronts. If you have built a CR-Box please reply with the number you've built and include a photo or two of the box to show others.
- 1/ Important study of over 10,000 classrooms. Upshot = lowering concentration of virus-laden respiratory aerosol particles in classroom air lowers inhalation dose of these particles and significantly reduces infection. Always been about this, folks.
- 1/ College students returning to dorms across North America. Just a reminder that a "classic" 4-5 MERV-13 filter #CorsiRosenthalBox in a 220 sq. ft x 9 ft can add between 15 to 27 ADDITIONAL equivalent ACH to the space (depending on flow setting, fan, etc.).
- Portable HEPA Filter Systems. 1/ The cost of retrofitting EVERY public school classroom in the entire US w/ a portable HEPA air filter w/ CADR = 300 cfm is approximately $1 billion w/ recurring cost of about $300M/yr for replacement filters. To be clear, EVERY single classroom.
- 1/ Inhalation dose of virus-laden respiratory aerosol particles w/ at least one infector in shared indoor space (two contrasting scenarios). Everyone wearing a (mediocre vs. high-quality) mask vs. nobody wearing a mask.
- This single CR-Box reduces fine particulate matter (PM2.5) concentrations in a shared office suite by greater than 98%. It will likely retain its effectiveness for 14 to 18 months based on its predecessor's results at a total cost of $0.90 to $1.16 per month per suite occupant.
- "Doctors are grappling with how to help" For starters, help people not to get infected in the 1st place. Lower exposure to virus-laden aerosol particles, increase ventilation, improve filtration (including portable HEPA & CR Boxes), & N95s (including in health care settings).The profound toll COVID-19 has had on heart health is only now starting to emerge. Doctors are grappling with how to help. “We are seeing effects on the heart and the vascular system that really outnumber, unfortunately, effects on other organ systems.” apnews.com/article/covid1…
- 1/ Been hearing of some push back by school districts over fears that fan motors on CR-Boxes may overheat and be a fire hazard. This thread addresses those concerns.







