OpenERV
@openerv.bsky.social
I've designed and am now producing energy recovery ventilators of many times the performance to cost ratio of those which were previously available for a home. An ERV transfers heat from outgoing to incoming ventilation air. Details at www.openerv.ca .
Ok so the cr-box donation guys in the uk got a buck ton of money to spend on air purifiers, and they just bought regular hepa things. The cr box foundation.
Not even like a deis box with ikea filters or something. Just regular hepa, exactly what they've spent 5 years criticizing.
Not even like a deis box with ikea filters or something. Just regular hepa, exactly what they've spent 5 years criticizing.
July 28, 2025 at 1:40 AM
Ok so the cr-box donation guys in the uk got a buck ton of money to spend on air purifiers, and they just bought regular hepa things. The cr box foundation.
Not even like a deis box with ikea filters or something. Just regular hepa, exactly what they've spent 5 years criticizing.
Not even like a deis box with ikea filters or something. Just regular hepa, exactly what they've spent 5 years criticizing.
Reposted by OpenERV
85% of Gaza is on the brink of death due to starvation. Israel could let aid in at any moment. And some people (like these men tried to do with me on Friday) are still trying to justify this atrocity.
There is no justification. This could stop at any moment. End the blockade now.
There is no justification. This could stop at any moment. End the blockade now.
July 27, 2025 at 10:59 PM
85% of Gaza is on the brink of death due to starvation. Israel could let aid in at any moment. And some people (like these men tried to do with me on Friday) are still trying to justify this atrocity.
There is no justification. This could stop at any moment. End the blockade now.
There is no justification. This could stop at any moment. End the blockade now.
I forgot to post that big quiet air purifier number 6 is done :). Unfortunately the cost of materials and parts is now $512 cad. Cheaper/better motor and driver boards are the low hanging fruit to get that down maybe by $85. Num 7 will be back to 400 rpm max, this one only does 350.
July 17, 2025 at 4:02 PM
I forgot to post that big quiet air purifier number 6 is done :). Unfortunately the cost of materials and parts is now $512 cad. Cheaper/better motor and driver boards are the low hanging fruit to get that down maybe by $85. Num 7 will be back to 400 rpm max, this one only does 350.
I haven't been saying much but continue working. I'm building jigs, trying to source a better motor, switch to ASA, and make the next machine. Networking to find teachers that can sneak units into their classrooms, and applying for more funding, which is not required yet but planning ahead :)
July 12, 2025 at 7:52 PM
I haven't been saying much but continue working. I'm building jigs, trying to source a better motor, switch to ASA, and make the next machine. Networking to find teachers that can sneak units into their classrooms, and applying for more funding, which is not required yet but planning ahead :)
Bluesky still doesn't work half the time in about five different ways... Mind you twitter is also about as bad. Do these people never test their stuff and notice it doesn't really work very well?
June 30, 2025 at 9:16 PM
Bluesky still doesn't work half the time in about five different ways... Mind you twitter is also about as bad. Do these people never test their stuff and notice it doesn't really work very well?
Big quiet air purifier number 5 is now done. 1110 cfm flow through merv 13 filters with one 36.3 dBa noise 300 rpm and no motor hum etc., just the blades whoosh. Goes up to 350 rpm for more flow. And I honestly don't know what to do with it. Sent out some emails looking for takers.
June 29, 2025 at 1:20 AM
Big quiet air purifier number 5 is now done. 1110 cfm flow through merv 13 filters with one 36.3 dBa noise 300 rpm and no motor hum etc., just the blades whoosh. Goes up to 350 rpm for more flow. And I honestly don't know what to do with it. Sent out some emails looking for takers.
It's time to declare victory for big quiet air purifier number 4. It can be controlled over Wi-Fi, and measures airflow, remembering and comparing flow to when the filters were new to give a percent flow indication. With a latest fan model it would get 1110 cfm @36.3 dBa, 1450 @ 47 dBa. However
June 18, 2025 at 5:15 PM
It's time to declare victory for big quiet air purifier number 4. It can be controlled over Wi-Fi, and measures airflow, remembering and comparing flow to when the filters were new to give a percent flow indication. With a latest fan model it would get 1110 cfm @36.3 dBa, 1450 @ 47 dBa. However
Reposted by OpenERV
Interesting new study making the rounds on the reduction that an air purifier can have on sick days in schools. Now, the question is: can we do way better? dagliano.unimi.it/wp-content/u... Only 12.5% reduction (1.34 days per student per year) with only 36% reduction in PM.
dagliano.unimi.it
June 12, 2025 at 9:57 AM
Interesting new study making the rounds on the reduction that an air purifier can have on sick days in schools. Now, the question is: can we do way better? dagliano.unimi.it/wp-content/u... Only 12.5% reduction (1.34 days per student per year) with only 36% reduction in PM.
Reposted by OpenERV
ICE crossed a line in LA
June 8, 2025 at 12:42 PM
ICE crossed a line in LA
Reposted by OpenERV
URGENT! ASHRAE 241 public comments close June 9th.
If you have time to comment, please read Joey Fox's excellent article on why Infection Risk Management Mode should ALWAYS apply: itsairborne.com/ashrae-241-a...
Submit comments here:
osr.ashrae.org/Online-Comme...
#COVIDisAirborne
If you have time to comment, please read Joey Fox's excellent article on why Infection Risk Management Mode should ALWAYS apply: itsairborne.com/ashrae-241-a...
Submit comments here:
osr.ashrae.org/Online-Comme...
#COVIDisAirborne
ASHRAE 241 Always Applies — Part 10
Dispelling the myth that it only applies during a pandemic
itsairborne.com
June 4, 2025 at 4:54 PM
URGENT! ASHRAE 241 public comments close June 9th.
If you have time to comment, please read Joey Fox's excellent article on why Infection Risk Management Mode should ALWAYS apply: itsairborne.com/ashrae-241-a...
Submit comments here:
osr.ashrae.org/Online-Comme...
#COVIDisAirborne
If you have time to comment, please read Joey Fox's excellent article on why Infection Risk Management Mode should ALWAYS apply: itsairborne.com/ashrae-241-a...
Submit comments here:
osr.ashrae.org/Online-Comme...
#COVIDisAirborne
I've long wanted to make a python program that would take a list of ingredients and find the most balanced diet that could be formed by them (i.e. how many grams of each). I made a mock up years ago with a giant spreadsheet and an optimizer plugin. You can make good diets out of all kinds of stuff
What’s wrong? Nothing, I just stopped by the store on my way home. Why do you ask?
June 3, 2025 at 5:26 PM
I've long wanted to make a python program that would take a list of ingredients and find the most balanced diet that could be formed by them (i.e. how many grams of each). I made a mock up years ago with a giant spreadsheet and an optimizer plugin. You can make good diets out of all kinds of stuff
Reposted by OpenERV
pediatric long covid is now more common than pediatric asthma, and there are no treatments for pediatric long covid
Long COVID’s surpassed asthma as the most common chronic illness among US children, impacting an estimated 6 million kids.
This scale of chronic illness is preventable with clean air infrastructure + destigmatized (& therefore increased) respirator (N95, FFP3, etc.) mask wearing.
hubs.ly/Q03pxzmC0
This scale of chronic illness is preventable with clean air infrastructure + destigmatized (& therefore increased) respirator (N95, FFP3, etc.) mask wearing.
hubs.ly/Q03pxzmC0
Long COVID in Young Children, School-Aged Children, and Teens
This JAMA Pediatrics Patient Page describes the symptoms of long COVID in children.
hubs.ly
June 2, 2025 at 7:17 PM
pediatric long covid is now more common than pediatric asthma, and there are no treatments for pediatric long covid
Jeeze, what's the dollars per quality of life year adding a bit of flouride gives us? Imagine inventing that. How spectacular. What an achievement. And then some fucking idiots do shit like this. People are handed things on a silver platter and then....
If the US stops fluoridating water, in 5 yrs American children would suffer an additional 25.4 million cavities, with an added cost of $9.8B, and loss of 2.9 million quality-adjusted life years, disproportionately borne by children currently on public health insurance or who lack insurance entirely.
Projected Outcomes of Removing Fluoride From US Public Water Systems
This cost-effectiveness analysis evaluates a large sample of US children to determine the associations of fluoridation cessation with oral health and national dental care costs.
jamanetwork.com
June 2, 2025 at 8:12 PM
Jeeze, what's the dollars per quality of life year adding a bit of flouride gives us? Imagine inventing that. How spectacular. What an achievement. And then some fucking idiots do shit like this. People are handed things on a silver platter and then....
The veho-600 broke itself last night and it's a mystery how. The heat break broke. I have spare parts and will fix it asap but they way the foundation crumbles away sometimes. The v3 broke for the first time ever yesterday too but it only took a minute to fix it.
June 1, 2025 at 3:38 PM
The veho-600 broke itself last night and it's a mystery how. The heat break broke. I have spare parts and will fix it asap but they way the foundation crumbles away sometimes. The v3 broke for the first time ever yesterday too but it only took a minute to fix it.
I'm pretty sure I'm going to call the big quiet filter box the Quokka box :). After the cute little marsupials that always seem happy, and apparently are actually quite friendly. They seem to be happy and make others happy :).
May 29, 2025 at 5:54 PM
I'm pretty sure I'm going to call the big quiet filter box the Quokka box :). After the cute little marsupials that always seem happy, and apparently are actually quite friendly. They seem to be happy and make others happy :).
Big quiet filter box cad is coming along. To recap, should get the same noise to cadr relationship as a set of about $3500 cad of the next best machines, like the medify a-112. Plus a fraction the running cost and better building automation integration, and filter health sensor.
May 29, 2025 at 1:08 AM
Big quiet filter box cad is coming along. To recap, should get the same noise to cadr relationship as a set of about $3500 cad of the next best machines, like the medify a-112. Plus a fraction the running cost and better building automation integration, and filter health sensor.
Mostly stayed off twitter today. Did most of the cad for the big quiet air filter/purifier, printed some parts, almost broke the big printer again but not quite. Trazadone appears to be useful for improving sleep, foot still not healing crap. Too much coffee again.
May 29, 2025 at 1:00 AM
Mostly stayed off twitter today. Did most of the cad for the big quiet air filter/purifier, printed some parts, almost broke the big printer again but not quite. Trazadone appears to be useful for improving sleep, foot still not healing crap. Too much coffee again.
Surprised to see this, I think about this most days. It's close to the core of how things do -or don't- get done imo, so I run into it often. Usually the "experts" don't even exist. People don't even know enough about expertise itself.
Exactly. People go around driving cars and riding in airplanes because they trust the experts who made them. Not everyone can be an expert on everything. The demonizing of expertise is dangerous.
It's often presented as a kind of conformity or groupthink to "trust the experts," but you do in fact need to do this to have a functioning society!
What is the alternative? Every person researches every single issue of public concern themselves?
What is the alternative? Every person researches every single issue of public concern themselves?
May 29, 2025 at 12:47 AM
Surprised to see this, I think about this most days. It's close to the core of how things do -or don't- get done imo, so I run into it often. Usually the "experts" don't even exist. People don't even know enough about expertise itself.
Reposted by OpenERV
Little Ume, our endangered tapir calf, has loved meeting so many of you over the past two weekends! 🩷 This growing baby needs lots of rest, so she’s been catching plenty of zzz’s behind the scenes and in her habitat. 😴
May 28, 2025 at 3:45 AM
Little Ume, our endangered tapir calf, has loved meeting so many of you over the past two weekends! 🩷 This growing baby needs lots of rest, so she’s been catching plenty of zzz’s behind the scenes and in her habitat. 😴
That's why they won't let you dig your own well. The thing is it's really hard to do something like that at the best of times. Goons with guns trying to stop you, or undo the work really don't have a hard time succeeding. The ratio is not favorable.
May 28, 2025 at 2:51 PM
That's why they won't let you dig your own well. The thing is it's really hard to do something like that at the best of times. Goons with guns trying to stop you, or undo the work really don't have a hard time succeeding. The ratio is not favorable.
Reposted by OpenERV
Sometimes I sleep badly even though I do everything right and it's terrible. Most of this week has been nearly a write off. It's only because I am so careful in how I do things that I get anything done at all sometimes :(.
May 25, 2025 at 9:59 PM
Sometimes I sleep badly even though I do everything right and it's terrible. Most of this week has been nearly a write off. It's only because I am so careful in how I do things that I get anything done at all sometimes :(.
A little bit of the story of discovery on a very challenging subject! So glad Al is on the case.
The article claiming that SARS-CoV-2 remains infectious in the air for 16 hours has been making the rounds on social media again.
I thought I would take this opportunity to discuss it, what it shows, what it doesn’t, and why I think it shouldn’t be taken seriously.
A thread.
I thought I would take this opportunity to discuss it, what it shows, what it doesn’t, and why I think it shouldn’t be taken seriously.
A thread.
May 25, 2025 at 9:57 PM
A little bit of the story of discovery on a very challenging subject! So glad Al is on the case.
I'm thinking I'll call the big quiet filter appliance the "Nautilus". Like captain Nemo's submarine! It's aspirational :). Thoughts? Or maybe "Quokka box" because it's happy and makes others happy :).
May 24, 2025 at 6:20 PM
I'm thinking I'll call the big quiet filter appliance the "Nautilus". Like captain Nemo's submarine! It's aspirational :). Thoughts? Or maybe "Quokka box" because it's happy and makes others happy :).