#CR box

[covid-safer-hotties]

Reference preserved in our archive (Daily updates!)

TL;DR: Corsi-Rosenthal Boxes deliver quality air filtration at upwards of 30% higher air exchanges than comparable HEPA filters on the market. Build 'em for covid. Build em' for wildfire smoke. Build 'em for allergies. Build 'em to clean the air.

Abstract Filtration performance of do-it-yourself (DIY) box fan filters deployed across a university campus was assessed over an academic year. Four DIY air filters were constructed from box fans and air filters with a minimum efficiency reporting value (MERV) of 13 and deployed in four spaces (two laboratories that include sources of particles and two offices). They were operated 9 hours daily with a programmable timer and were continuously monitored with power meters. Particle concentrations in the spaces were continuously monitored with low-cost nephelometers. The particle size dependent clean air delivery rate (CADR) and single pass filtration efficiency for each box was measured in a laboratory before deployment and every 10 weeks, for a total of five measurements over 40 weeks. We find that these DIY box fan filters maintain robust performance over time, with each air filter maintaining at least 60% of its initial CADR at the end of the 40 week study even with daily operation in environments with modest particle concentrations. CADR values for particles of 1.0–3.0 μm optical diameter averaged 34% higher than CADR values for 0.35–1.0 μm particles, aligning with MERV 13 filter size-dependent filtration expectations. Reductions in CADR over time were attributed to a reduction in filtration efficiency, likely due to a loss of filter electrostatic charge over time. There was no strong indication that increased resistance due to particle accumulation on filters appreciably decreased flow rates over time for any of the fans. The long-term robustness of DIY box fan air filters demonstrates their validity as a cost-effective, high performance, alternative to portable high efficiency particulate air (HEPA) filters.

[laurellynnleake]

Just swapped out the filters on our 1st Corsi-Rosenthal cube, and what a difference! Dusty old filter above, minty fresh one below.

This particular filter box spent 10+ months on low inside our house, catching tons of wildfire smoke, PM2.5, and COVID-19 aerosols, as well as pollen, dust, and mold. Glad all that's on THERE and not in our lungs!

I highly recommend building your own CR box for your home, school, work, mutual aid meet ups, etc. All you need is 4 MERV-13 filters (sold at most hardware stores), a 20" box fan, scissors, cardboard, and duct tape.

It ends up costing about $75-100 - much cheaper and performs a lot better than a lot of fancy air purifiers. Building it with 2 people takes about an hour (mostly to measure and cut out the weird shroud thing), and swapping in new filters is much faster.

Check out the Clean Air Crew website to get started on your own! We protect each other! 💪😷✨

[pipzeroes]

The tune is based, with permission, on “How To Build A Fence” by Nova Scotia singer/songwriter Bob Snider.

How To Build A Corsi-Rosenthal Box

It’s time to clear the air Cause COVID is still there… And if you want a cheap machine that will cancel tox- -ic pathogens in the air, Well then you oughta hear ‘bout the Corsi-Rosenthal Box.

First you get your fan, Keep the box that it came in You’ll need it for the floor; Now get filters, count 'em, four. What rating? MERV-13. The hardware store will know what you mean. As always, you’ll be stuck, Without your tape for duck. Now add a box-cutter, you're on your way to warding off the pox! This is everything you need to build a Corsi-Rosenthal Box.

With the filters, build the shell In order to build it well Look for the big arrow; It shows how the air should flow. First filter you begin With the arrow pointing in Then build a filter fence By butting up against Tape it up so every filter interlocks Now you’ve got four strong walls for your Corsi-Rosenthal Box.

Don’t worry there’s not much more But you’ve got to make a floor That shouldn’t come as a shock Since that’s why you kept the box So cut your square to fit Tape it on the top of it Turn it upside down and then You’re ready for the fan Now with all you’ve done you’ll find that you’re approx- -imately one or two steps from done your Corsi-Rosenthal box

Before you do the rest, You’ve got to give the fan a test You'll feel like such a jerk, If it turns out not to work, When you’ve used up all that tape To attach it to the crate And covered gaps and slits With tape and cardboard bits

Not to complicate, just make a little slit in the tape So the cord can escape Or else the thing will never go Make a little slit then cut another bit Also with a slit They fit Opposite And overlap them now you’re sealing soundly so– You’re sure it’s only through the filters air can blow– Also— They take out dust and pollen and smoke Which is good to know Tape the corners of the fan just to increase the rate of flow– Oh! Congratulations you just built one of the building blocks, For being safe to respire (Ahhh…) Now sit back and admire Your lovely little Corsi-Rosenthal Box

[bandomfandombeyond]

ha. fuckin HA.

one of the bitches who contributed to getting me kicked out of the "queer-oriented" "radical" camp for advocating that people mask and carrying around my CR Box CAUGHT COVID at it.

the Lord rebukes!!!!!!!

[pandemic-info]

Enjoy Clean Air While You Drive with the Mini-Mini Corsi-Rosenthal Box - Tex-Air Filters

[copperhawkthoughts]

If you are in British Columbia, ime, Filtrete 1900s (MERV13) are $30-$35 a piece at Amazon/Home Depot/Canadian Tire, which obviously adds up if you need 4.

That said, you can make a version of this with just one filter and the fan, which will be better than nothing.

Cleanaircrew.org has instructions for a single-filter version that I was able to make with supplies from Canadian Tire for about $90CAD after tax (For Living box fan, 20x20 Filtrete 1900, duct tape)

Pros: works, cheaper up front than my Winix air purifier, replacement filters easy to source

Cons: pretty noisy, no carbon filter, no pre-filter (could add those, for extra cost)

to anyone in the areas impacted by the wildfire smoke, my #1 biggest piece of advice as someone whos been dealing with wildfire smoke in the NW united states for years, is build yourself a Corsi-Rosenthal Cube

they perform as well as expensive HEPA air cleaners, and are comparatively VERY inexpensive. all you need is a box fan, 4 air filters, a piece of cardboard, and some duct tape!!!!

i think it took us maybe a half hour to put ours together, if that, and we replace the filters every 3 months. it's really made a HUGE difference, both when the air quality is bad, but also with our allergies

[undead-knick-knack]

Get force caged idiot

[rjshope]

revenge is sweet😏

[spirit-doll]

Wait , what even happened when you first met??? Why did he bite???

I'm telling you right away, I can't draw chromatic aberration.

previous part | first part

[otterlyart]

As Kevdak's body slumps... it shrinks back down to its average size, and you crumple to the ground, smiling.

[carsthatnevermadeitetc]

Honda Ballade 1500 CR-M Extra, 1983. The Ballade was an up-market version of the Civic sold through Honda's Verno dealerships. The second generation model had semi-concealed headlamps in keeping with the styling trend shared with other Honda Verno products including the 2nd generation Prelude. It was powered by a 1.5 litre 12-valve EW series engine.

[covid-safer-hotties]

[namsoek]

yeah go little guy

[sea-buns]

Never did I expect myself to be mourning the absence of english essays and writing exams and theatre class critiques. Do you understand how fucking amazing of a grade I could get on an analysis of trauma in Critical Role? On Lou Wilson and Emily Axford's finesse in portraying the heavy expectations and double standards placed on children? On Ylfa Snorgelsson's relationship to death? On the journey of a man's relationship to violence? On an analysis of grief in Dimension 20? On the pitfalls of youth? On the dynamic between humanity and religion? On the journey of self-discovery and acceptance? On love in all its forms? On the nature of choice? On everything Brennan Lee Mulligan has to say about capitalism? On the tragedy of im/mortality? On Gerard and Elody's divorce? On the unfeeling and aimless happenstance of the universe? On the role of fate and destiny? I'm not saying it would be easy. I'm saying can you imagine how fucking cool it would have been to turn in 5 pages about a dnd show, feeling good about it?

[immult]

malloy would post an imogen/dancer wip and all i could do is sigh and pick up a pen. it's too good.

[natp20]

the emissary is unfortunately a child of divorce