3 days ago

All the places we've been to so far, even small neighbourhood ramen joints have had really good #ventilation.
Reminded of that at Ajinoya today (pic1). I was a bit concerned but remembered/figured having the griddle right in front it was ventilated well.

2nd pic from a trip a couple of weeks ago to another #Osaka spot (stay tuned for a #Ramen report/thread) - there was even a mister and you could see all the vapors getting sucked away

Ceiling with lights and 2 big square fan vents
A big black square fan vent with streak moisture vapor being sucked into it on one side
3 days ago

So-- parts of the WHO Clean Air conference is in english. I just briefed through it real quick, the English version (well it is listed as the english version but some of the presentations are in different languages so you have to breeze through it) but it is at: and this screenshot is one gold nugget of info they had presented (higher outbreaks in classrooms with higher CO2 levels) #ventilation #covid19 #CovidIsNotOver #COVIDisAirborne

Deacon Jericho
5 days ago

Wer eine Impfung mit den aktualisierten #Corona-Boostern haben will findet mitunter keinen Arzt, der die #Impfung auch anbietet.

Impfwillige in #Bremen können nun die 116117 anrufen. Dort wird ihnen dann ein Termin vermittelt. Damit soll der Zugang zur Impfung erleichtert werden.

#ImpfenSchuetzt #StikoEgal #LassDichImpfen #AlterEgal #CovidIsNotOver #CleanAir #Ventilation #Tests #MasksInMasses

IT News
2 weeks ago

Hackaday Prize 2023: AutoDuct Smart Air Duct - Modern building techniques are relying more and more on passive elements to improv... - #2023hackadayprize #thehackadayprize #ventilation #greenhacks #cooling #heating #shutter #green #duct #home #hvac #vent #fan

I made one of those Rimsky-Korsakov boxes. #covid #wildfires #ventilation #CorsiRosenthal

A Corsi-Rosenthal box assembled from four air filters and a box fan.
Carolyn Barber, MD
2 weeks ago

The no-brainer that works in every school is a good portable (HEPA)filter in every space that's sized approp for the space," said AQ expert/engineer Jeffrey Siegel.

We often think about the💰related to upgrading HVACs... “The real thing we should be looking at is what's the cost of not doing it?"
#ventilation #filtration #AirQuality
#CleanAir #schools

Carolyn Barber, MD
2 weeks ago

It’s not rocket 🚀 science.👇

Not peer reviewed yet, but an RCT led by Prof @cathnoakes found that HEPA filtration significantly reduced school absenteeism during a large Covid wave.

From the CDC: “Ventilation interventions can reduce the spread of disease…”

We need to continue to advocate for clean air in schools, bldgs, offices…everywhere!:)
#filtration #ventilation #COVID19 #CleanAir #ASHRAE

Dr Joe Pajak
2 weeks ago

'The Covid-19 pandemic highlighted the importance of good #ventilation in the prevention of #airborne diseases. Many classrooms are poorly ventilated, increasing the risk of a child or member of staff contracting an airborne illness.' @JhongflowImg et al

Dr Joe Pajak
2 weeks ago

Creating healthy #schools:
'🇺🇸US schools that used improved outdoor #air #ventilation together with other mitigation strategies had lower rates of Covid-19 transmission compared to the rest of the community.' Report: @JohnDMacomber et al., @HarvardHBS

Earth Notes
2 weeks ago

On Condensation Management - Learn how you can best avoid problems with condensation, damp and mould in winter. #mould #condensation #ventilation -

There must be a reason why the UK 'Health Security' Agency removed public health from its name.

No recognition that we are still in a pandemic with an airborne virus, risks of long covid and & that UK kids are not being offered the vax, #CleanAir or #ventilation.

But yes, keep recommending hand washing

#Schools #COVID19 #CleanAir #Ventilation #LongCovid

Deacon Jericho
2 weeks ago

@Fischblog PS: auch gegen Pertussis helfen #Masken #Ventilation und #Luftreiniger

Dr. Clare
3 weeks ago

@PaulWermer @thepoliticalcat @Porpentina2017

I’m an old enough fart too and I worry about all of us.

Old farts don’t deserve to die early (young) and struggle with long Covid and then die young anyways.

#MaskUp #CorsiRosenthalBox #ventilation

3 weeks ago

@Sheencr @trishgreenhalgh

Thanks v much for flagging up the #IndependentSAGE session on youtube today.

Just want to say a personal thanks to those taking part - was a great session, really useful and interesting information, analysis and ideas/examples (& answers to public questions on current #vaccine etc.).

And all in easy watch, easy understand mode! 😀 Thanks!

#covid #cleanair #ventilation #vaccine #publichealth

3 weeks ago

Recommendations for placing a #CorsiRosenthalBox in a room with one window and some, not-great, cross- #ventilation?

In the door blowing toward the hall - sucking outside air in from the window and blowing filtered air, likely with some virus particles, into the rest of the house

In the window blowing outside air into the room (may as well just use a regular fan)

In the window blowing inside air out the window (ditto)



Carolyn Barber, MD
3 weeks ago

have a new shot for a huge swath of the population to better protect ppl against the newer variants or long Covid. Tighten your skates, folks. WE CAN DO BETTER. #universalvaccine #nasalvax #ventilation #longcovidtreatmenttrials #Covid #longcovid #booster

3 weeks ago

Dominique Costagliola : «Avec le Covid, on a vu ce qui arrive quand on fait du court-termisme» #Eaux_usées #testing #covid #masques #ventilation #vaccin

Earth Notes
3 weeks ago

On Condensation Management - Learn how you can best avoid problems with condensation, damp and mould in winter. #mould #condensation #ventilation -

Clean Air Stars
3 weeks ago

A regular reminder that the goal is *not*

“A #HEPAFilter in every classroom”,


“Achieving #cleanair delivery targets in every classroom”

This may be mechanical #ventilation, multiple portable air filters, or both.

The goal is achieving real risk reduction, not a box ticking exercise with little impact.

The portable air filter recommendation tool at was built with this is mind, helping achieve clean air delivery targets at required noise levels.


Screenshot of air filter recommendation tool
Screenshot of air filter recommendation tool
Screenshot of air filter recommendation tool
Screenshot of air filter recommendation tool

Excellent news. Plastic dividers are crap and block ventilation - they make COVID risk higher.

CP24: Changes coming to Metrolinx, including removed plastic barriers and increased service

#COVID19 #Ventilation #CleanAir #Transit #PublicTransit #PublicHealth

Clean Air Stars
4 weeks ago

This noise level alert from this watch is interesting. Could be useful if watches or phones had a similar warning for prolonged elevated CO2 to guide people into ventilating their spaces or limiting exposure duration where someone’s risk profile means it’s important for them to know.
#IAQ #CleanAir #Ventilation

Photo of an Apple Watch showing a noise level alert
Carolyn Barber, MD
4 weeks ago

“So, Joe, if it's not that hard to do, not super expensive, offers better health outcomes and better schooling outcomes, what's up, why hasn't this money been spent?”

Nice piece with Joe Allen, director of Healthy Buildings at Harvard, on how to improve indoor air quality in schools. #Ventilation #COVID19

1 month ago

And so, children, that’s how we ended up spending your COVID money on sports infrastructure #ESSERfunds #Covid #Ventilation

@Billius27 @harriettmb Grateful for comprehensive manifesto by #healthcare workers. I liked the part about “multi-layered protections. That’s a useful phrase. People take #ventilation and #vaccination for granted, ignoring #testing and #tracing. I was unfamiliar with the term #nosocomial, but not the concept. Members of my circle of friends, family working in healthcare note patients’ vulnerability to #airborne disease. Elder friends awaiting care in ERs contracted Covid-19.

IT News
1 month ago

Review: WAINLUX K8, a Diode Laser That’s Ready to Work - Rarely a week goes by that some company doesn’t offer to send us their latest and ... - #laserengraver #ventilation #laserhacks #diodelaser #grbl_esp32 #airassist #airfilter #featured #interest #reviews #laser

Carolyn Barber, MD
1 month ago

It’s time. Clean air can keep schools open…

An Italian study of schools estimated that students in classrooms equipped with ventilation systems or devices that deliver clean air had at least a 74%⬇️ risk of infection than those in classes with windows open.
#ventilation #COVID19 #CleanAir

1 month ago

@arstechnica from this it’s clear they don’t have the data to know IF it’s a VOC if governments aren’t reporting it to them. The fear of running blind is being realized. #BA286 #MassDisablingVirus #MasksWork #Ventilation #Filtration

Carolyn Barber, MD
1 month ago

less effective. Please CDC, do a better job at protecting & informing the public about a crippling virus that is leaving 1 in 10 (per CDC numbers) with long Covid. Thanks. #Covid #CDC #LongCovid #Ventilation

Elizabeth MacKenzie
1 month ago

Hey, my response to @GottaLaff about the Covid-19 policy in my psychology practice is the most boosted thing I've ever posted! I have been feeling like the last virgin in college with the level of precaution I take. The boosts make me feel so much better.
#MaskUp #Ventilation #Filtration #Covid

Louise Locock
1 month ago

Saturday, lunch for a birthday celebration in a restaurant private dining room. 14 of us, one person had a cold but there was really powerful #ventilation operating. As we sat down to eat, one bloke (not the host) said, 'It's too cold, we all want that switched off, right?' One woman said, 'Oh but some of us are menopausal.' He ignored her and told the waiter to switch it off. Today we learn the host and one of her relatives have tested positive for #Covid, so they had to cancel a holiday. Sigh

1 month ago

Urgent issue: #CDC Poised To Weaken Masking, Infection Control via @forbes #aerosol #ventilation #masks #N95. #InfectionControl Thx to @brosseau_lisa @NationalNurses @jane_nnu @CorsIAQ for interviews. Public comment ends 8/25

Nurses wearing baggy blue masks
1 month ago

@plaguepoems @RussSharek
Those erasable deadly #Covid cases with “comorbidities” = the 10% of the people in the population who are disabled

Which now includes people who’ve had Covid multiple times, who eventually stop being “most people”

They become the “other people”

They should be asked to define who are these Most People and how many there are

And what happens to the ones in the room right then who aren’t included

#CovidIsNotOver #ventilation #disability

@augieray TY for this 🧵 . #COVID is not done with us and may never be. Durable vaccine protection hasn't happened yet, is difficult to achieve, and will take time to prove. Public health and engineering measures-- #Masks #Ventilation -- do help a lot, but governments have downplayed the actual risk of infection/re-infection giving naysayers the opportunity to put out disinformation that harms many. Vaxxed/Masked here in Hawaii.

This piece focuses on indoor air quality (viral and otherwise) in schools, but is absolutely instructive about air purification systems folks can use in their homes or businesses.


#AirFilters #Ventilation #Covid

2 months ago

@sidawson @rmi

We got one of these for our school (1...), 14 classes... I did some early experiments with class and staff room, meeting room - I have been 'cracking' a window on each side of the room every day since.

I highly recommend this
#ventilation #airflow

Clean Air Stars
2 months ago

While portable air cleaners as a component of a #cleanair strategy can be cost-effective, there are situations where:
1. they will add little value to a space with adequate ventilation
2. incurred costs fail to deliver the desired clean air delivery targets.

Here is a single device in a well ventilated school library delivering 340m3/hr (1.5L/p/s) clean air.
If it were poorly ventilated, for around the same budget you could deliver 2700m3/hr (15L/p/s) clean air.

#Ventilation #HEPAFilters

Photo of a portable air cleaner in a library
Photo of a portable air cleaner in a library
Photo of an air ventilation outlet in a library
Screenshot of a result from the Cleanairstars air filter recommendation tool showing 4 SmartAir devices on medium speed delivering 15l/p/s under 40dBA for 50 people for $3508 upfront cost.
Clean Air Stars
2 months ago

This is why even indoors, the act of opening windows where there is little air movement (wind, convection currents) to exchange air may not sufficient to adequately reduce bioaerosol concentrations.

From: @DrZoeHyde

#IAQ #CleanAir #Ventilation

Madhouse Muse 😷🦋
2 months ago

When a team of doctors, scientists and engineers at Addenbrooke’s Hospital and the University of Cambridge placed an air filtration machine in #COVID19 wards, they found that it removed almost all traces of airborne SARS-CoV-2.

#Covid #SarsCov2 #IAQ #ventilation #AirFiltration #HEPA #CleanAir #CovidIsAirborne

Mx Jookia (Yes)
2 months ago

I'm at the point of ordering parts to implement a simple system for extracting fumes from a 3d printer and soldering.

The plan is to have both the printer and solder space go to a T junction and inline fan. But as both aren't constant I will have variable pressure/extraction.

This seems like a fine setup on paper. Anyone out there want to tell me this is a bad idea?

#electronics #3dprinting #ventilation

2 months ago

Changing Australia’s approach to managing COVID-19 pandemic may help reduce burden on health system – Croakey Health Media “Many layers can be applied to drive down #transmission and minimise the impact of the #virus, including a comprehensive #COVID19 education campaign, improving data collection and focusing on #ventilation and indoor #AirQuality.” Via @jvipondmd

Clean Air Stars
3 months ago

“One thing that is apparent — our buildings are not currently designed sufficiently for mitigation of airborne diseases. The discrepancies between current indoor air quality standard (ASHRAE 62.1) and control of infectious aerosols (ASHRAE 241) is evidence of how much work needs to be done to provide safe and healthy indoor environments.“
- @joeyfox

#Ventilation #IAQ #CleanAir #COVIDisAirborne

Sumana Harihareswara
3 months ago

New post:

I follow 4 main principles to reduce my risk of catching #COVID:

1. Avoiding sharing unfiltered air with people outside my household
2. Noticing how safe I am & raising precautions accordingly
3. Focusing on protecting myself over protecting unmasked people (in general)
4. Spending money

I detail those principles + my specific protocols (#masking, #ventilation, self-#testing, &c.), with links to product vendors.

#covid19 #COVIDIsNotOver #COVIDIsAirborne

3 months ago

Associations between illness-related absences and ventilation and indoor PM2.5 in elementary schools of the Midwestern United States - ScienceDirect “Higher #classroom #ventilation rates significantly reduced #illness-related absences.

Higher concentrations of indoor long-term monitored #PM25 were significantly associated with increased illness-related absences.”

Madhouse Muse 😷🦋
3 months ago

Seattle Space Needle is another #CovidSafeBusiness! This should be a model for all public spaces for #IAQ #IndoorAir #CleanAir

This iconic building has upgraded:

-#Ventilation: air changes over at least 6x per hour and in some spaces up to 30x per hour".

-#Filtration: Using HEPA and Merv-13 filtration

-#UVC light behind-the-scenes to clean the air as it changes over through the HVAC system.

#CovidPrecaution #CovidCautious

Anita Y Cheng
4 months ago

Still trying to catch up with #TWiV. 😅 May 18, 2023:

The CDC finally issued #ventilation guidance for buildings! 5 air changes per hour. To compare, negative pressure isolation rooms in hospitals have at least 12 air changes per hour. A standard hospital room has 6 air changes per hour. Dr. Griffin would love to see air changes per hour posted on public buildings to make educated decisions about #COVID risk. 1/


4 months ago

The US Centers for Disease Control and Prevention has extensively updated its ventilation guidance on helping prevent indoor transmission of the virus that causes Covid-19.

The agency had advised people to ventilate indoor air before, but this is the first time a federal agency has set a target – five air changes per hour – for how much rooms and buildings should be ventilated.

#CleanAir #Covid19 #CovidIsNotOver #Ventilation

4 months ago

As of May 12, 2023, the CDC recommends "at least 5 air changes per hour of clean air in occupied spaces" and published a table of cost considerations for various ventilation and air filtration strategies

#covid #longcovid #sarscov2 #ventilation

Gina Helfrich, PhD
4 months ago

RT birdsite

“This is HUGE.

CDC, for the first time ever, has set a minimum ventilation target (5 air changes per hour) for all occupied indoor spaces. The CDC released new and updated guidance on ventilation in buildings this morning”

#CDC #ventilation #covid

Screenshot of a tweet from @vlamers reading:

This is HUGE. 

CDC, for the first time ever, has set a minimum ventilation target (5 air changes per hour) for all occupied indoor spaces. The CDC released new and updated guidance on ventilation in buildings this morning
4 months ago

5 ACH is not enough, but in most places will be an improvement.

Also interesting this comes out 5/11/23, the day the pandemic emergency officially ends.


Aim for 5 
Aim to deliver 5 or more air changes per hour (ACH) of clean air to rooms in your building. This will help reduce the number of viral particles in the air. You may need to use a combination of ventilation (air supply, filtration, and air treatment) strategies to reach this target.

Upgrade filters 
Use filters rated MERV-13 [4 or higher, when possible. Using higher-rated filters in your heating or air conditioning system can remove more germs in the air than lower-rated filters.

Turn your HVAC system “ON” 
Set your ventilation system to circulate more air when people are in the building. You can do this by setting the thermostat's fan control to the “ON” position instead of “AUTO.” This will make the fan operate continuously but can increase fan energy use, so limit use to when needed.

Add fresh air 
Bring more clean outdoor air into spaces by opening windows and doors and using exhaust fans. Even small openings can help.

Use air cleaners 
Air cleaners (also known as air purifiers) filter air with high-efficiency filters that remove germs from the air. Choose one that's the right size for your space.

 Install UV air treatment systems 
UV air treatment systems can kill germs in the air. 
Use portable carbon dioxide (CO2) monitors 
A portable CO, monitor can help you determine how stale or fresh the air is in rooms. Readings above 800 parts per million (ppm) suggest that you may need to bring more fresh, outdoor air into the space.
Madhouse Muse 😷🦋
4 months ago

For the first time, CDC has set a minimum ventilation target- 5 air changes per hour (ACH)- for all occupied indoor spaces and released new and updated guidance on ventilation in buildings:

#IAQ #Ventilation #ACH #IndoorAirQuality #COVID #COVID19 #HVAC

Anita Y Cheng
5 months ago

51% of K-12 #school districts did not report using any #ventilation improvements in accordance to CDC #COVID guidelines. Interestingly, high-poverty school districts reported implementing the most ventilation strategies, relatively. 12/


My three siblings, on the other hand, seem to understand their individual relationships to greater humanity, and take personal responsibility seriously. They all wear #respirators, do not allow themselves to justify spreading disease to others, understand the importance of #HEPA and #ventilation, and ask me for advice, guidance, support, etc. when needed (which happens to be frequently!).

I couldn’t be luckier to have them. ❤️

This would be less of an issue if the theater took precautions like air purifying, improving #ventilation, imposing a #MaskMandate for audience members, testing the cast members…but no. Because we’re all sick of #COVID and want to “get back to normal” and all.

Deacon Jericho
5 months ago

@pezmico What kind of "UV light" might that be?

I have a hard time to find reliable info about UV/ UVC / Far-UVC. That is maybe helpful technology, but it is potentially dangerous, too.

Which solution/ product has usability for the "normal" user?

#UV #UVC #DavosStandard #CleanAir #Ventilation #Filtration #CovidIsNotOver

I wrote a blogpost about our experience with demand-controlled central ventilation in a family house. It's in Czech, but DeepL translates it well.
#energy #ventilation

UPDATE: My brother stayed #COVID FREE according to all test results over the past 7 days!

How can we trust the test results given the evasiveness of #kraken?

Maybe we can’t completely, but the fact that he took #RAT on days 0 to 6, waited until 6+ days had gone by, THEN got his #PCR and #NAAT samples taken (all negative) seems good.

PLUS no development of symptoms. Slept in a #N95. #HEPA and #ventilation also helped keep him healthy!

#CovidIsnotOver #CovidIsAirborne @novid

Heidi Li Feldman
7 months ago

Belgium will be requiring proprietors of indoor spaces to post information about how ventilated indoor air is. I hope this becomes a trend worldwide. #Covid #Flu #Ventilation #COVIDisAirborne #Health

8 months ago

By opening my door for 10 minutes, I lowered the CO2 in my house from ~1350 ppm to ~615 ppm.

It's important to exchange air, esp in the winter months, it helps clear the mind, it's good for the body, and helps get rid of allergens and viruses that might be stuck in the air in your space.

#Ventilation #COVID #COVIDisNotOver #COVIDmitigations

Jeri Dansky
8 months ago

So nice to see some places still have good #Covid protocols in place.

This is from Booksmith in San Francisco, about tonight's event: "ID and proof of full vaccination, including at least one booster shot, will be required at the door. #Masks will be required throughout the duration of the event, capacity will be limited to allow indoor distancing, and we'll have extra #ventilation in place."

h/t @mulegirl #Covid19

8 months ago



Where the heck are new #ventilation standards for all #industry, #entertainment, #dining, and #transportation? Could save millions in the next epidemic.


Joe Pajak (Dr)
8 months ago

One way to help 'Avoid COVID and Other Respiratory Viruses' @TactNowInfo
'Increase #ventilation as much as possible to maintain CO2 level <600 ppm to ensure an adequate supply of fresh air and old air building up is being sucked out of the space'.

8 months ago

Canada has surpassed 50,000 Covid related deaths.
(Crickets in the news media)

This is equal to obliterating
North Vancouver, BC,
the West End, Vancouver, BC,
Brandon, Manitoba, or
Belleville Ontario, for example.

The BCCDC last reported 27 deaths due to Covid in BC in just one week.

I am outraged!
Are you?