Aaron Collins

2.6K posts

Aaron Collins

Aaron Collins

@masknerd

Goal is to test and evaluate the best masks out there. Mask up and stay safe!

Minneapolis, MN Katılım Ocak 2021
123 Takip Edilen49.1K Takipçiler
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Aaron Collins
Aaron Collins@masknerd·
All my data is available at this Google Drive link. I know I have been getting a quite a few messages looking for it. It includes master data set, FAQ, Kid's mask recommendation and mask images drive.google.com/drive/folders/…
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Aaron Collins
Aaron Collins@masknerd·
@JonathanCrock @ukhadds It derives from workplace protection studies, where they measured respirator fit and then measured actual exposure when wearing a respirator. They determined roughly that if you had a Fit Factor of 100, you had a 95% probability of having a >10x reduction in exposure (APF 10)
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Jonathan Crock
Jonathan Crock@JonathanCrock·
@ukhadds .@ukhadds This is a different topic: How was a fit factor of 100.0 established as a standard (vs. a FF of 98.2 or 101.7 etc.)?
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Al Haddrell
Al Haddrell@ukhadds·
How long a microbe remains viable in the air will depend on where it resides in/on an aerosol. So then, how do scientists figure out where? Answer: they use their understanding of the processes involved in industrial food production. Namely, coffee. youtu.be/HHwp4tLPK9M
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𝙶𝚘 𝙰𝚜𝚔 𝙰𝚕𝚒𝚌𝚎 📚🐇
𝙶𝚘 𝙰𝚜𝚔 𝙰𝚕𝚒𝚌𝚎 📚🐇@aliceinempire·
Hey Covid safe community! I need new mask recommendations for my husband. He manages a kitchen and has to use ear loop masks at work so he can pull them down to taste. We had been paying like twenty bucks for a pack of 50 KN95, but he needs to upgrade. Any affordable ideas?
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Aaron Collins
Aaron Collins@masknerd·
@sharidelic You can reuse N95's, if AQI in your area is good(low) then fit will be the first issue. If exposed to dense wildfire smoke I would not use them for more than a day. P100 just use until it's hard to breathe in.
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Shari Acharya
Shari Acharya@sharidelic·
@masknerd I live near the Eaton fire and has been Coviding, so have some N95s handy. But, with Cvid we could reuse masks. Can we reuse them in the current environment in LA?
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LangT@langtblu·
@masknerd I cannot find these on Digikey anymore. Any idea where I can buy them now online that are real?
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Aaron Collins retweetledi
Mike Hoerger, PhD MSCR MBA
Mike Hoerger, PhD MSCR MBA@michael_hoerger·
Good to hear our Covid Defense Kits for people w/cancer I sent out pre-hurricane are arriving safely. Sent out another batch today. The Kit includes a booklet, masks, air purifiers, & tests. I think people are also just happy to be treated with dignity in difficult times.
Mike Hoerger, PhD MSCR MBA tweet media
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Aaron Collins
Aaron Collins@masknerd·
@sri_srikrishna @ukhadds @CliveBeggs I think the disconnect is that we care about the dose of virus received, so while some fraction of 0.65um particles have viable virus, they have 1/1000th amount of a 7um particle(assuming the same concentration). Its all about computing the inhaled dose.
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Devabhaktuni "Sri" Srikrishna
Devabhaktuni "Sri" Srikrishna@sri_srikrishna·
@ukhadds @masknerd @CliveBeggs just reposted this study of viable virus sampling fractionated by particle size among infected subjects. It found viable virus even in all fractions including submicron fraction (0.65 μm).
Devabhaktuni "Sri" Srikrishna tweet media
Prof. Clive Beggs@CliveBeggs

More evidence that COVID is airborne. Great study recently published (nature.com/articles/s4146…) in Nat Com. First to culture live virus is small aerosols that can be inhaled deep into the lungs. #Covid #COVIDー19 #Ventilation

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Al Haddrell
Al Haddrell@ukhadds·
There's been a lot of discussion about the size of exhaled aerosol that contains the most virus. For the most part, it's thought to be in the ~1 to ~5 micron range. There's a little bit of variation between studies, but that's roughly the size of concern (“Viral”).
Al Haddrell tweet media
Piotr Wasik@piotr_wasik

@fitterhappierAJ (2/2) Are there lab tests (e.g. using bitter spray) showing particulate filters also work well with aerosols? People assume they do because they look cool, but I'd like to know. They are just industrial dust filters, are respirators safer? @antiviral_mktng @LolaGerms @ukhadds

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Aaron Collins
Aaron Collins@masknerd·
@AB85025310 @ukhadds It depends on how the scores were collected. If done using N99/N100/FFP3 mode(no classifier) then it's hard to say which one is better in context to COVID but all would be good in my book. If using N95 mode(w/classifier) then higher score is "best", but all are good in my book
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A B@AB85025310·
@ukhadds 2/ Eg my typical scores: 3M Aura N95 - 170/270 Drager FFP3 - 1,500/1,800 Easimask FFP3 - 8,000/10,000 How much safer would I be during, eg, air travel in the Aura vs the Easimask? I’m assuming the very tight seal my Easimask score must represent would mean significantly safer?
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Aaron Collins
Aaron Collins@masknerd·
@SmartAirFilters Woohoo....I am just excited to see more and more sir monitors and air cleaners in the world.
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Smart Air
Smart Air@SmartAirFilters·
@masknerd Aaron, you won our air purifier 🎉 Congratulations 👏
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Smart Air
Smart Air@SmartAirFilters·
🕛 Time's ticking. We're waiting for your answers until midnight tonight (GMT+2). Don't miss out.
Smart Air tweet media
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Aaron Collins
Aaron Collins@masknerd·
@Prusa3D you should check out what we managed to do with the latest XL 5-head printer. Co-molded silicone with water solvable BVOH molds allowed us to make some cool and intricate parts. The full stack including hardware is open-source too! #OpenSourceHardware #3Dprinting
OpenAeros@OpenAeros

Cool to see the OpenRespirator, and D2S tech we have been developing, get a some traction in the maker space. Thanks @hackaday for the write-up! hackaday.com/2024/09/04/mul…

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Aaron Collins
Aaron Collins@masknerd·
@KLHM2010 I haven't tested them, but the list of masks I haven't tested vs. have tested grows every day 😃
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Aaron Collins
Aaron Collins@masknerd·
@amandalhu @ErinSandersNP @JimRosenthal4 @linseymarr Device is still working and depending on the design it will vary how much you see, but causes no harm and doesn't mean its not filtering. The entrainment issue is why personal airflow designs are very hard to make work for this same reason.
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Aaron Collins
Aaron Collins@masknerd·
@amandalhu @ErinSandersNP @JimRosenthal4 @linseymarr I can't see the original tweet, but I assume its about dust on the fan blades downstream of the HEPA filter. This is super common and caused by entrainment of ambient air that gets pulled in near the fan blades. Same reason shroads on CR Boxes add more flow, stops this effect
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Erin C. Sanders, MSN, WHNP (She/Her)
Erin C. Sanders, MSN, WHNP (She/Her)@ErinSandersNP·
Anyone? Beuller? Air quality experts? Before I break out a screwdriver? cc: @amandalhu @masknerd @JimRosenthal4 @linseymarr
Erin C. Sanders, MSN, WHNP (She/Her)@ErinSandersNP

@CleanAirCrewOrg I have several @honeywell HEPA filters. Has anyone discovered a way to clean the internal fans that get caked with dust? They are the fans blowing HEPA filtered air into the room. Do I have to disassemble the machines? Design seems flawed cc: @CorsIAQ @kprather88

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Aaron Collins
Aaron Collins@masknerd·
@OpenAeros needs some help! If you have any connections with anyone familiar with IEC 61010 and CE compliance we would love to chat. We get the basics, but want some help navigating the labs & companies. Basically just need the inside scoop since this our first time.
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Aaron Collins
Aaron Collins@masknerd·
@piera_systems I haven't measured the rooms, but per HVAC design its about 3 ACH, so this gets us closer. Note that ASHRAE 241 is per person based, so we don't care too much about eACH.
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Piera Systems 🇨🇦
Piera Systems 🇨🇦@piera_systems·
@masknerd What was the eACH before the air purifiers? If the “extra 2.5 eACH” is not netting eACH total, then ASHRAE 241 is not being met. For optimal viral transmission limitation each room needs 6 eACH.
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Aaron Collins
Aaron Collins@masknerd·
What does an extra ~2-2.5 eACH cost for a classroom? This year it was $30 for air filters and $3 in⚡️, for a whopping $1.43 per kid per year!!! Took 7 hours to do 23 rooms. This ain't rocket science. Not a paid endorsement, no connection to brand but 0/23 failures in 3 years🤷‍♀️
Aaron Collins tweet media
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David Keating
David Keating@DavidLKeating·
@masknerd While I have one, I'm not sure I'd recommend it. It is not AHAM verified and the company provides no CADR claim. I see no ETL rating either.
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Aaron Collins
Aaron Collins@masknerd·
@mnstatefair I hope this is something you can address with your security teams. COVID cases are sky high here in MN right now, and people should be able to take precautions to protect themselves and not be harassed. Your FAQ clearly says its okay. reddit.com/r/Minneapolis/…
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Aaron Collins
Aaron Collins@masknerd·
@taniataylorpowe There are trade-offs with FarUVC, and school adoption to comply with various safety regulations is not trivial. This comes from a person who founded a Far UV nonprofit --->osluv.org/team
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taniataylorpowers
taniataylorpowers@taniataylorpowe·
@masknerd Hepa filters need to be constantly changed & this expense does not account for the constant need for filter replacements. When it comes down to money & Efficiency Far UVC is actually less expensive in maintaining & less human error of someone forgetting to turn it on. Far UVC #1
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Keşfet

@JonathanCrock @ukhadds @Washable95 @ghhughes @TMaritanoAquino @levylevilevoo @aliceinempire @AwanRad