Coronavirus Outbreak: Part 4

Very true. We have HEPAs and CR boxes at home and I’ve had positive reactions to them which has been interesting.

We hosted DW’s extended family of 22 people in December and had a CR box or HEPA in every room on the main floor and basement (multiple in some rooms where we expected many people to congregate)). When people were leaving, one of my MILs cousins said to me “It was really nice to see filters in every room. It made me feel more comfortable.”

I’ve had other people ask about the filters in our house and how to purchase them so that makes me hopeful that there is some interest. Cost aside, it is an easier sell than masks.

While mass incorporation of filtration is expensive, I am hopeful there will be technological advancements to make clean air cheaper. Also, the cost savings in reduced healthcare needs, less missed days of work/school and a healthier population may be more than the cost of clean air, but that is purely my speculation. I haven’t seen a study.

There also needs to be more education of the benefits which as you point out extend far beyond Covid. Cleaner air in classrooms has been associated with increased concentration, lower absence rates and higher test scores. Each classroom in our school district has a stand alone HEPA filter donated by a family in the area, but when school started for my kids, neither class had the filter turned on. Fortunately, both were turned on after I emailed the principal with a request.


Can’t agree more.

It’s an uphill battle. I personally know a guy with a doctorate in biology, teaches biology, has a research lab for something involving I think cicadas, and his major response is to keep disinfecting surfaces, even now. I’ve been mentioning air exchange and cleaning since March 2020. I’m considered uninformed.

Cleaner air must also benefit students with asthma, and other respiratory challenges.


Which HEPA filters & CR boxes (will have to look that up…not sure what it is) do you use? I got one for my son for his college dorm apartment - common area living room/kitchen.

That one’s called an air purifier. Hope it’s helpful.

Then this smaller for bedroom.


I teach preschool music. I wore a mask or did class outside until this school year. I still hold class outside when I can, but stopped masking this school year. I balance the risk/reward….I really needed to connect in that way with them again….I still mask in all other public settings & really only socialize outdoors now. I have my 85 yo dad & homebound sister that I do things for regularly so try to protect them as well as myself. Anyway, I have a classroom on the end of the building so I open the door….or if too cold, I open it in the couple minutes between transitions to new students. I only have the kids 20 minutes at a time…6 total classes. It’s a fairly large room so we can move, jump, etc around.

Wondering if I should get one for my classroom. I never thought about it until the heat went out last month & I brought my own space heater in for a couple weeks.

Clean air really should be more common practice.


I’ll let @davej speak to what he uses, but I can answer this part. It’s a DIY one and they’ve actually proven to work surprisingly well.

ETA: A lot more recent examples and tips are posted on Corsi’s Twitter


I qualify this by saying I am not an expert on indoor air quality so I can only report on what I have done and what I have read.

I’ve been trying to learn as much as I can about clean indoor air because I think it makes a difference (not just for Covid, but for other respiratory illnesses, allergies, dust exposure, etc). It seems intuitive that breathing clean air would be healthier (just like drinking clean water). And when I change the filters on my HEPAs and CR boxes, the filters are dark gray. If not on the filters, that stuff would be getting into my family’s lungs.

@amvanhoose_701479 post above covers an explanation of a CR box. More recently some folks have designed CR boxes with PC fans because PC fans are quieter than box fans. The box fan CR boxes can be loud. Of course, everyone has a different definition of loud. If I were handy, I would make the the PC fan CR boxes myself, but since I am not handy, I purchased some from I think there may be another company or two out there also selling these.

I also have HEPA filters from Coway and Medify Air. I don’t know enough to recommend one brand of HEPA over another. I have used this website for ideas of how many HEPAs to use in a room: Air Filters - Clean Air Stars. This website also lists many brands of HEPAs with specs.

I follow Joey Fox on both Twitter and Medium as he seems to be one of the top clean air experts and has written about both CR boxes (with regular fans and with PC fans) and HEPAs.

I caution that this stuff can get expensive, but getting sick and missing work/school also has a cost (in addition to the downside of feeling sick for a period of time and risks of longer term issues) so in my mind (for me) the latter costs justify an investment.

I think the technology in this area will continue to get better, cheaper, quieter and smaller. Some smart minds out there thinking about how to accomplish all this.

If I were teaching in a classroom, I would want some combination of HEPAs/CR boxes in the room. And if my child were in college, I would purchase a HEPA or CR box for the dorm room. My brother purchased a HEPA for my niece’s dorm room.

Does this help?


Thank you so much for sharing what you’ve gleaned. Yes, it does help!


Thank you for sharing your knowledge. You’re always so helpful in digging up all the info!


:woman_shrugging: Rumors say it’s coming…


For reference:


High quality masks work. Probably not 100% (most things in life are not 100%), but high quality masks are very effective in reducing risk are airborne illness transmission. It is amazing that this is not a widely accepted fact.


Yeah, it just happened to be mathematically ~100% in that study. And they were using the equivalent of N100s (I think fit-tested) to get there. But. It really rankles me that they aren’t doing more to reduce in-hospital transmission when quality masking is such an an obvious way to do so.

Really interesting study comparing PCRs and rapid tests in preventing onward transmission.

TL;DR If I’m understanding this correctly…In this setting, they were basically equivalent. So, even though the PCRs picked up more infections in their share of groups, the groups using rapid tests didn’t have more secondary infections, so the cases the rapid tests didn’t catch (that PCRs could have) weren’t infectious.

Really nice summary slide (wish more studies included these):

SMDH that we have established, relatively low cost, widely available, basic tools (vaccines, quality masks, rapid tests, Paxlovid) that so few are using. Resulting in ~300 deaths/day right now.

71k tallied over the last year. For those that want to compare this to flu “burden”, the CDC estimates there are 1.3 deaths for every 1 reported, so Covid deaths over the last year are probably around 92k.

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Agree. One of my friends suspects that staffing is a big factor in hospitals not requiring masks. Many hospitals are already struggling with staffing and my friend thinks some staff would quit if required to mask.

And then you add in long covid and the much higher rates of post-Covid infection cardiac, vascular, neurological and immunological issues (plus issues not yet known).


Yeah, this just isn’t a sustainable approach. It’s just a matter of if/when the frogs realize the pot of water is on its way to boiling and how cooked they get before then. :woman_shrugging:

Maybe I’m completely wrong. I would love to be wrong. But the data keeps accumulating with about 80% of it in one direction. :face_with_peeking_eye:

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Not a happy thought…



Interesting. I wish the author disclosed whether then differences between 2.9% in September, 2.7% in October and 2.8% in November were statistically significant.

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Guess it’s time to start highlighting this:

YLE did a whole write up on it this week. If nothing else, note the underlined bit.


OMG @amvanhoose_701479 --are we living in the Twilight Zone!!!


Here’s my favorite headline in the past few days
Column: As measles spreads, ‘herd stupidity’ grips Florida’s government (

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IKR? This timeline has some seriously bad writers. I really need them to get to the “time travel back and kill the beetle that walked left at the fork instead of right” part already. :roll_eyes: