1/ A context slide from my CITRIS webinar on 3/16/22.
We know it is possible to achieve a CADR > 800 cfm for a Corsi-Rosenthal box. So, let's compare its impact in a realistic dorm room & classroom relative to air changes per hour in, say, a hospital infection isolation room.
We know it is possible to achieve a CADR > 800 cfm for a Corsi-Rosenthal box. So, let's compare its impact in a realistic dorm room & classroom relative to air changes per hour in, say, a hospital infection isolation room.
2/ In a standard 2-person dorm room (where masks are unlikely to be worn when two people are sleeping 10 ft away from one another for 8 hours!) the CR box yields an aerosol particle reduction equivalent to 24 air changes per hour (ACH).
3/ Without any other ventilation, this is 2 x a hospital isolation room! Measurements of natural ventilation in my home garage with the large garage door wide open have been in the range of 15 to low 20s for ACH depending on outdoor wind conditions.
4/ Upshot - Aerosol particle concentrations in the dorm room drop to a tiny fraction of what they would have otherwise been. Just sayin', folks.
5/ For a 700 ft2 classroom the eACH increase using a #CorsiRosenthalBox at 800 cfm is 7.6 ACH. When I apply ASHRAE 62.1 2019 calcs to K-12 classrooms I've studied in Texas and then convert to ACH, values typically range between about 2.5 to 3.5/hr.
6/ Adding these values to 7.6 ACH equivalent yields 10.1 to 11.1 ACH --- that's almost a hospital isolation room.
7/ Don't tell me that we cannot make classrooms MUCH safer without a small investment of time and money.
8/ The capital, electricity, and recurring filter replacement cost for a classroom of 25 students works out to an average of about $3/student/year over three years.
9/ That's one Venti Iced Coffee per student every year for a massive reduction in their exposure to virus-laden respiratory aerosol particles, wildfires smoke particles and more.
10/ The average cost of educating a student in the US is $13K/year. So, we are talking about $3K/year + $3 investment for a massive health benefit & reduction in probability of COVID-19 spread. That's a 0.023% increase, a Venti Iced Coffee, folks.
11/ That anyone has to think twice about this is painful. Just do it!
That is $13K + $3….
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