1/ The guiding principles of the original #CorsiRosenthalBox design were (1) cost-accessibility (reduce disparities in ability to breathe cleaner air) & (2) effectiveness (in range or better of more expensive commercial HEPA air cleaners). (photo courtesy of @JimRosenthal4)
2/ The original concept exceeds expectations in each area and has now been proven highly effective by many researchers w/ additive equivalent ACH that easily get many classrooms above 9-10 equivalent ACH (CR Box + ventilation) at relatively low cost.
3/ The recent NIOSH/CDC study indicates that two #CorsiRosenthalBox es in a classroom can add greater than 12 ACH to ventilation ACH - likely exceeding 15 equivalent ACH total. As some context, this exceeds ventilation design for most hospital isolation rooms. Yep. Knew that.
4/ For a classroom of 25 students integrated over 3 years (including capital cost, replacement filters & recurring energy costs of a single #CorsiRosenthalBox) the cost per student for much cleaner air is less than 1 Venti Caffe Mocha per year.
5/ As context, the avg cost to educate a child in the US is $13,000/yr. We can signficantly reduce student & teacher inhalation dose of virus-laden respiratory aerosol particles (& other aerosols) for less than 0.034% of cost of educating a child. (photo courtesy Andre Knoesen)
6/ Very low cost. Dramatic improvements in indoor air quality in classrooms. Less exposure to virus-laden aerosol particles, wildfire smoke, allergens, and even endocrine disrupting chemicals as per recent Brown University study. This is a no brainer, school district folks.
7/ There's been an evolution of a lot of GR8 new #CorsiRosenthalBox designs. I applaud these (keep them going). But let's not forget the original guiding principles & continue to strive for even more cost-accessible & effective systems as well. A spectrum of cleaner air for ALL.
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The Corsi-Rosenthal Foundation is a tax-exempt 501(c)3 nonprofit organization (EIN: 35-2779639). Our goal is to provide cleaner air in school & other public buildings with particular interest in underserved and/or vulnerable communities.
We do this largely through financial grants, materials, or a combination of the two to build Corsi-Rosenthal boxes (CR Boxes). The Corsi-Rosenthal Foundation is run by consensus of a Board of Directors.
All Board members are volunteers and receive no salary. As such, 100% of donations go directly to grantees for cleaning the air for their communities. No donations are used to purchase materials from companies affiliated with any Board members.
The "Sources" chapter of @theNASEM
report on "Health Risks of Indoor Exposure to Fine Particulate Matter & Practical Mitigation Solutions" is approx 60 pages and full of source-specific details. Check out the report here: (some highlights in thread)
Cooking is a very large source, whether heating w/ natural gas, propane, electric. Emissions specific to natural gas for cooking & other heating processes considered in (2)
The "Sources" chapter of @theNASEM report on "Health Risks of Indoor Exposure to Fine Particulate Matter & Practical Mitigation Solutions" is approx 60 pages and full of source-specific details. Check out the report here: 👇 (some highlights in thread)
Cooking is a very large source, whether heating w/ natural gas, propane, electric .. Emissions specific to natural gas for cooking & other heating processes considered in (2)
(1) Americans spend the vast majority of their time indoors. Prior to the pandemic, on average Americans lived to be 79 yo (now lower) & spend almost 70 of those years indoors, 54 years insides residences.
(2) Most fine particulate matter (particles with diameters of 2.5 microns or less) are inhaled indoors. This is true for fine particles of both indoor as well as outdoor origin. (more on sources of fine PM in a future tweet).
(3) There is ample evidence that exposure to fine particulate matter causes a range of adverse health effects (will summarize in a future tweet).
1/ This CR Box (the one on the right!) has now totaled operational time equivalent to an entire in-classroom school year. Both it and its cohort of three other CR Boxes continue to perform with a high level of effectiveness across a wide range of particle sizes.
2/ Four CR Boxes were placed in different indoor settings on the UC Davis campus, from a relatively clean 4-person office suite w/ VCT flooring to a particle-challenged soils lab.
3/ Each CR Box consists of four 20" x 20" x 2" MERV-13 filters (3 boxes w/ filters from the same manufacturer and the 4th from a different manufacturer). A 20" x 20" box fan was used to draw air through each CR Box.