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Lazarus Long Profile picture
@LazarusLong13
Aug 11, 2021 • 29 tweets • 14 min read • Read on X
A mega thread on the ultimate DIY air filter known as the Corsi/Rosenthal Box (@CorsIAQ/ @JimRosenthal4).

Take it into work. Donate a couple to your school classroom if they'll let you.

Illustrations beautifully done by @ughberta, discovered through @kprather88.

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But my little angels don't transmit CoVid!?

They have ACE2 receptors, which SARS-COV-2 targets.

They get it and transmit it.

And those little bodies have a thermal plume wafting CoVid up to you.

. link.springer.com/article/10.100…
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Always a typo, no matter how many times you go over it....

Sorry - @Poppendieck has a great FAQ here - used up above!



Another classic FAQ is one maintained by about 10 aerosol scientists.


poppendieck.com/IAQ/COVID19%20…
tinyurl.com/FAQ-aerosols
Above...about 40,000 tweets ago, you mentioned 5 microns...and seemed excited about it. Why?

Respiratory aerosols (emitted when we breathe, talk, laugh, yell, sing, cough, sneeze) carry SARS-COV-2.

And 85% of them are 5 microns or smaller.

Corsi/ Rosenthal boxes in action!

Classroom








Used for wildfires:


For STEM fair





Used for Bacon. Gets it's very own tweet. Mmmmm. Bacon....

For sports palace.


For no reason given
















Pulling this up into the thread for optimum visibility.

Thank you, David!

(A great follow!)
A great resource for clean air:

Your lungs will thank you!

Next tweet...this is the hand sanitizer for the lungs you've always needed. Just without that bad smell...

This spacing is really excellent.

The one thing I would change, based on @Poppendieck's recommendation is to flip the box to be pointed up.

So any dried respiratory aerosols (carrying SC2) on the ground are not lifted off the ground (re-aerosolized).


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Would these help in a hospital with already great ventilation?
(H/T
)

Yes.

Preprint, but Dr. Marr is serious money:



Great discussion of why they still help in such already great ventilation:


And that tweet author is the lead on this study showing basically the same:


Same study, but a great tweetorial, too.

Ontario, Canada bringing in 20,000 portable air cleaners.
Someone asked how to dispose of the filters.

Put on your N100 elastomeric respirator (more comfortable than N95).



Carefully, pick up the Corsi box and gently take it outside.

Since you used painter tape, gently peel it back to get the fan off.
Separate the filters and gently place in a garbage bag. Do not shove them in as might have virus in them and don't want the garbage bag blowing the virus back on you.

Tie the bag tight. Toss into garbage.

Make new box!

Why not spray disinfectant on it?

Because by the
time the garbage bag degrades the virus will have been activated...

nejm.org/doi/full/10.10…
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Corsi/Rosenthal Thread Update:

Some folks, (mostly teachers) cannot bring in an air cleaner. But can bring in a fan.

Here's a fan that has a filter built into it! So, a stealth air cleaner.

"Lasko FF305 Air Flex 2-in-1 20-inch Box Fan and Air Purifier in One with MERV10 Image
Air Purifying Filter"

Won't be as good - but something is better than nothing!



H/T @kprather88 for this. She is NOT endorsing it - I am just thanking her for the knowledge of its existence, and I am the one suggesting it would make a great stealth one.walmart.com/ip/Lasko-FF305…
The filters here: are 13-A - so I would buy one and swap out the MERV 10 that it comes with.



No affiliation, just these are hard to find.
@Al_pha_Q2 @CorsIAQ @JimRosenthal4 @ughberta @kprather88 @CathNoakes might require slower air to do its job. Not as familiar with that tech, so happy to stand corrected if wrong.
@Debbie_Winslow_ @ManTh1ng @tafkak @CorsIAQ @JimRosenthal4 @ughberta @kprather88 @DavidElfstrom But ...I am NOT the expert here, so if any of the actual experts could "like" the above tweet, or otherwise correct my ruminations, I'd be most appreciative :). .
@Karthik07720496 @CorsIAQ @JimRosenthal4 @ughberta @kprather88 improved by implementation of 2 portable air cleaners.

Dr. Schofield's excellent study here - with an explanation of why:


And yes, it will reduce virus transmission by removing the respiratory aerosols that carry SARS-COV-2.

&

@dgurdasani1 @laineydoyle @DavidElfstrom @fischelfe @CorsIAQ @JimRosenthal4 @ughberta @kprather88 @CathNoakes @Poppendieck But round fans are addressed here with some examples:


Overall FAQ here - includes all build instructions for 5/4/2/1 filter versions. (Actually working on finishing up the 5 version).

cleanaircrew.org/boxfanfilterfa…
cleanaircrew.org/boxfanfilterfaq
Mega Corsi/Rosenthal Box Thread Update:

David Elfstrom has done a fantastic triangle filter build with estimated CADR.


It, along with everything else, is now in the FAQ:


One of the FAQ's is the Gallery - check it out!
cleanaircrew.org/boxfanfilterfa…
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Mega Corsi/Rosenthal Box Thread Update - Adding the Baskett Box (3 filter build).

Wow! An update to the Mega Corsi/Rosenthal Box Thread that kind of went a little viral.

Here's a fan that has a filter built into it! So, a stealth air cleaner.

"Lasko FF305 Air Flex 2-in-1 20-inch Box Fan and Air Purifier in One with MERV10."

Next tweet - a surprisingly Image
good performance.

I AM impressed!

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More from @LazarusLong13

Lazarus Long Profile picture
Jan 30
What Have You Got Against A Mask?

1/9 What Have You Got Against A Mask? In a black and white photograph, a black woman wearing a white duckbill respirator, gazes deep into your soul. Her eyes tell you that .... The simple act of wearing a respirator (KN95, N95, or better) can save your life, if they're used properly and every time you are in a public place / outside your home. Wearing a mask helps prevent transmission of airborne viruses such as SARS-CoV-2, RSV, influenza, and more. Despite profit-based claims otherwise, we are still in a global COVID pandemic. Mask up to protect yourself and others from illness, disability...
What Have You Got Against We, The People? A DELTA plane landing on their words that have killed thousand. Disabled hundreds of thousands, and destroyed us all. We are writing on behalf of Delta Air Lines to the Centers for Disease Control and Prevention (CDC) to reconsider the current guideline for 10 days of isolation in fully vaccinated individuals who experience breakthrough COVID-19 infections... We propose a 5-day isolation from symptom onset for those who experience a breakthrough infection. Delta Airlines to CDC Director, Dec. 2021 THIS IS TO ENRAGE YOU.
What Have You Got Against A Mask? In a black and white photograph, a young teenager stares into your soul. His eyes say, What Have You Got Against A Mask? The simple act of wearing a respirator (KN95, N95, or better) can save your life, if they're used properly and every time you are in a public place / outside your home. Wearing a mask helps prevent transmission of airborne viruses such as SARS-CoV-2, RSV, influenza, and more. Despite profit-based claims otherwise, we are still in a global COVID pandemic. Mask up to protect yourself and others from illness, disability (Long Covid), and death. For more information about...
Read 9 tweets
Lazarus Long Profile picture
Jan 28
This may be the biggest news of the decade. Completely overshadowed by shenanigans in the White House.

It looks like H5N1 reinfections are entirely possible. This means that our farms are going to be a never-ending circulating pump of H5N1.

This. Is. Not. Good.

/1 But reinfections suggest that the virus, called H5N1, could circulate on farms indefinitely, finding opportunities to evolve into a more dangerous form — a “high-risk” scenario, said Louise Moncla, an evolutionary biologist at the University of Pennsylvania. “You could easily end up with endemically circulating H5 in dairy herds without symptoms, obscuring rapid or easy detection,” Dr. Moncla said.
How long can our luck go on?

We now have Bobcats with the one mutation that we really don't want to see.

The PB2 E627K mutation.

"The PB2 E627K mutation is a dominant adaptation marker in most human-adapted influenza A viruses. " PB2 E627K is a mutation in the PB2 gene of the influenza A virus that changes the amino acid glutamic acid (Glu) to lysine (Lys) at position 627. This mutation helps the virus replicate more efficiently in mammalian cells. How it affects the virus Replication: The PB2 E627K mutation helps the virus replicate more efficiently in mammalian cells. Disease severity: The PB2 E627K mutation can cause more severe disease in mammals. Temperature: The PB2 E627K mutation helps the virus replicate in the lower temperatures of the upper respiratory tract of mammals. How it affects humans Human-adap...
Read 9 tweets
Lazarus Long Profile picture
Jan 14
If you are taking public transport like in NYC? Mask up.

Pretty cool Master's Thesis for Biology - on bioaerosols like SARS-COV-2.

Set up a prototype aerosol sampler?

And find it in 52.9% of the samples in Beijing Railway Station and 44.4% at Beijing Subway Station.

/1 The subway station selected for this experiment was Xidan Subway Station, a major subway station on Lines 1 and 2 in Beijing and serves as an important subway transit hub. The passenger flow of the station is expected to be around 7,000 – 12,000 during rush hours and less than 7,000 during non rush-hours. A total of 27 samples have been collected, with the first 10 collected around 9-10am in the morning or 3-4pm in the afternoon, which is considered non-rush hour and 17 collected during the rush hour period. Sampling was collected for 17 weeks in total, not necessarily consecutively taking ...
Bioaerosol Sampling in the Exit Area of Beijing Railway Station. BC500 was placed near the exit area of the Beijing Railway Station where passenger flow is expected to be the largest. Beijing Railway Station is one of the oldest train stations in Beijing with a large passenger flow that is around 60,000 passengers per day. The bioaerosol sampling device in this scenario is placed at the exit area of the train station, where passenger flow is relatively higher, ensuring better chances of sample collection. However, passenger flow, unlike the subway station is not divided into rush / non-rus...
Never mind this.

"Firstly, the high positive rate highlights the potential for airborne transmission of these viruses in crowded public areas"

Definitely do not flag this to anyone in a big city looking to ban masks.

Definitely do not do that with this new study. The findings of the experiments conducted in this thesis indicate that viruses including SARS-CoV-2 and influenza are not only present but also potentially widespread in these public spaces, which has several important implications. Firstly, the high positive rate highlights the potential for airborne transmission of these viruses in crowded public areas. This is consistent with existing literature that suggests densely populated environments with limited ventilation can facilitate the spread of respiratory viruses. The detection of multiple pathogens reinforces the importance of considerin...
Yes, nothing to see here.....

At Beijing Railway Station, positive samples were
52.9% SARS-CoV-2
47.1% Flu A
23.5% Flu B.

At Xidan Subway Station, positive samples were
44.4% SARS-CoV-2
18.5% Flu A
7.4% Flu B At Beijing Railway Station, 52.9% of samples tested positive for SARS-CoV-2, 47.1% for influenza A, and 23.5% for influenza B. Additionally, 29.4% of the samples were positive for two pathogens, and 11.8% were positive for all three pathogens. The total percentage of negative samples at this location was 29.4%. At Xidan Subway Station, 44.4% of the samples tested positive for SARS-CoV-2, 18.5% for influenza A, and 7.4% for influenza B. Moreover, 18.5% of the samples were positive for two pathogens, with no samples testing positive for all three pathogens. The total rate of negative samples ...
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Read 5 tweets
Lazarus Long Profile picture
Dec 31, 2024
Sara Anne Willette's visualization tool - is not a list. It is a visual representation of a group of accounts, so that she can remove herself from them.

It uses only publicly facing data, available per the X TOS, and the API, not scraping.

IT WILL NOT EFFECT YOU AT ALL. Image
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There are some accounts 👇 and their followers that SHE JUST WANTS NOTHING TO DO WITH.

It is her choice to remove herself from any account she wants.

The actual data?

✔️ account creation date
✔️ the username of the account,
✔️ who they follow.

All obtained legally per TOS. The list. Ooo so scary. You all are acting like high school kids.
Describes user name
The LOCATION that you saw in the blurry used to get you all fired up!?

Picked up from the front page of the profile, but NOT USED.

I live in Temporarily Enabled, USA - but it is not my physical location.

That's it.

Some additional thoughts, from me, not Sara. Not using location
Read 18 tweets
Lazarus Long Profile picture
Dec 23, 2024
Ozone. A pollutant no matter where it is - outdoors or indoors.

#DYK that indoor inhalation is 25% to 60% of total intake? Per Weschler?

iaqscience.lbl.gov/increases-ozone

#DYK that MOST indoor ozone comes from OUTDOORS? Per Weschler?

pmc.ncbi.nlm.nih.gov/articles/PMC16…

Truly worried?

🧵 Accounting for the differences between indoor and outdoor air ozone concentrations, Weschler [6] has estimated that indoor exposures to ozone are typically 45% to 75% of total exposures. Because breathing rates are lower when people are indoors, the indoor inhalation intake of ozone is typically 25% to 60% of total ozone intake. These estimates may be low for the population most affected by ozone—infants, the elderly, and those with respiratory and cardiovascular disease. Consequently, if there is no threshold concentration for the health effects of ozone, or if the threshold is low, roughl...
Although there are indoor sources of ozone, in most buildings indoor ozone has been transported from outdoors (Weschler 2000). Indoor ozone concentrations track outdoor concentrations with a slight time lag that depends on the air exchange rate. Ozone is removed by indoor surfaces as well as by gas-phase reactions, and hence, indoor concentrations tend to be smaller than co-occurring outdoor levels.
If you are TRULY worried, you should be focused on eliminating ozone, right?

You would be slipping into people's threads and sharing these cheap DIY activated carbon builds, right?

Because if you are TRULY concerned about ozone, you would not be slipping into threads of people showing pictures of their new FAR-UVC Torches - for any other reason, but to share the good word that the miniscule ozone generated could be eliminated.

VIRUS and OZONE free air.
Read 8 tweets
Lazarus Long Profile picture
Dec 21, 2024
ACH ACPH - Air Exchanges per Hour.

An important topic since way before 2020, but given fresh vigor with our collective interest in clean air. Not just disease free air, but VOC, PFA, microplastic, mold, UFP, PM 1, PM 2.5, etc.

The outside air will infiltrate inside.

🧵
That ☝️picture is not typical.

Typical ACH - there can be general estimates, but every house is different. You can determine your own, as shown by @jljcolorado with help 👇👇. Jump to the section shown 👇.

medium.com/@jjose_19945/h…

The estimator is here
docs.google.com/spreadsheets/u… How to estimate the ventilation rate in practice
I am grateful for input and suggestions on this topic from Andy Persily, Shelly Miller, Dustin Poppendiek, Ty Newell, Rich Corsi, Bill Bahnfleth, and Jeff Siegel.
The thread about that article is here. Some excellent discussion on it by some very good scientists, including those Dr. Jimenez acknowledges. Those folks are also on Xitter.

Read 15 tweets

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