https://www.jameco.com/Jameco/workshop/Howitworks/dysonairmu...
"Buffeting" of air is not a practical issue when using a fan - you want a fan that can create a lot of air flow.
The Dyson fan comes across form first then making up reasons to explain the form retroactively. It feels like an interesting look is the goal rather than something that's actually better.
Am I wrong about this? Do people that have the fan like it? Is it better? I've only played with one in a store, but haven't owned one myself. I have owned Vornado fans which I liked.
Another one that comes to mind is the Molekule air filter which is basically fraud.
Large HEPA filters work, people should use them.
My favorite: https://medifyair.com/
Chemistry sets, m-80s, model rockets, playgrounds, coaster brakes, whatever kids did before "play dates" and anything intricate with small parts.
Would you be as good of a programmer today if that was true? I remember spending an entire week trying to figure out how strings worked in QBASIC, when I was in 5th grade. There was no internet and I only had the Apple IIGS Basic manual to work with. I tried and tried and tried and eventually figured out that it had something to do with those $ symbols. Eventually I got the hang of it. I guess the point is, that challenge and struggle with simple things helped me develop the attitude to overcome truly difficult things later. Maybe this is more just memories of childhood than anything..
* Windows 95 removed all thought of the user as a programmer, killing things like QBasic.
* Apple was doing likewise, even killing Hypercard.
* The web wasn't in its prime yet, limited to HTML 2.0 and 3.2, and really lousy JavaScript.
* Even electronics was tough, since DIP parts were being replaced with SMT, and the service manual was starting to become a relic, but things like Arduino and RPi didn't exist yet, and making PCBs was $$$$$.
* Shop classes were on the decline in schools, but makerspaces weren't in yet.
I feel bad for kids growing up then. Short of installing a Linux distribution, kids were left out in the cold for being anything other than consumers of technology.
There was really a golden age in the eighties and early nineties, and we seem to be in another golden age right now.
Lawn darts, BB guns, wrist rockets, bottle rockets (I know you said M-80s, I had those too, but bottle rockets could be shot at friends), can of WD-40 (with requisite red straw) plus a lighter, backyard archery set.
Love you Mom and Dad! 70s were great!
One uses the name of a toy in a derogatory manner, the other is a straight-up derogatory term for a group of people.
At first I also didn't know why is one of colleagues sounding "weird" - never would've thought they had their fan running, until one product manager asked "Hey X, do you have a fan running nearby?"
I mean I get the "born in the wrong generation" vibe, but at the same time it's easy to get blinkered and not realize what came instead. In a LOT of ways, they (and we) were born in the RIGHT generation.
With an app, you’re using a tool for its intended purpose. There’s little joy in discoverability because you’re following the rules the developer set.
That’s why the fan can be more fun; it’s not generational. The fun is in exploring a novel feature in something you though you thoroughly understood.
When the novelty is over with the app, you delete it (was the hour of fun worth getting your data mined?) and return to the boredom (find the next app). With the fan, you simply stop and it continues to be useful. Without you taking deliberate action, everything returns to the way it was. Except for your mind, which metaphorically expanded and wants to see what else can be used in creative ways.
Is there a word in English which exclusively means hand-digits or fingers+thumbs or digits-toes?
I'd rather raise daredevils than anxious wrecks. My best friend has a kid who's always climbing on stuff, falling down, getting hurt. That kid is going to grow up to be awesome.
I scream when I saw my kid trying to stick a key into an electrical outlet, and I screamed when I saw my kid trying to put a finger into a vornado fan.
Modern fans aren't the same as the box fans we grew up with. And adult would likely walk away with an emergency room bill and a bunch of stiches. A small child would likely lose a finger.
I have, know what happened? Nothing.
I have a couple 80-100 year old GE fans. Putting your finger in the front doesn't do anything but push it out. Which makes sense if you look at the shape of the blades. The side and back are a little scarier, but i'm guessing unless you really jab it in fast, or get unlucky in some way the worse that will happen is some scraped up skin. They are definitely not _designed_ to sever fingers, for that you need a tablesaw. And none of them have enough rotating mass or HP that you can't stick your finger in the back and actually stop them by keeping your finger against the blades as they try and push your finger.
So, I'm not saying it cant happen, but your kid probably has a greater chance of losing a finger in your car door, or various other places like that before you have to worry about the fans. If you want to experiment with this find something approximating a finger and give it a try, maybe the woody bits of a leftover piece of asparagus.
Glad I still have that finger. It didn't feel particularly close to being severed, it just cut to the bone and then pushed my finger out of the way. Kinda NBD, but ER visits to teaching hospitals are always annoyingly slow...
Where is the fun in that? I say sharpen the blades and make it a real teaching moment.
I told him that I thought I could do it without the glove. He told me to give it a try and I did. What I did was promptly fall on my ass and that's how I learned the power of electricity.
When I was 16 I was working on my ham radio's linear amplifier. I was certain that I had shorted all the capacitors but one still held a charge and once again with much more force knocked me on my ass.
For days I could see the line up my arm where the electricity travelled. After that I always grounded the capacitors three times just to be sure!
At least, not so far. I don't plan on finding out if it really is "third time lucky" lol
I never told my parents about it because I would have gotten yelled at.
At camp we put crickets on the electric fence, but nothing happened to them, so I grabbed the electric fence, and that was a powerful jolt. I never did that again, either.
One xmas when I was less than 5yo I jammed a knife into our 240v socket and blew the fuse on the Electricity Board side of the fusebox. They had to send an engineer out to turn the power on so we could continue cooking the turkey.
The other is from a sibling comment. With primary school, 10 years old, we went to the Lake District and were introduced to electeic fences by everyone holding hands with the person next to them, and the teacher explaining that he would touch the wire with the back of his hand to avoid muscle contraction. Because I was "that kid" I was placed at the far end of the chain, where I assume it tingled more. That was fun.
We used to put PP9 batteries on our tongues for tingles. Just for fun.
I do recall dangerously letting .22 blanks off with a brick and a piece of brick making an entry and exit wound through the outside fleshy part of my hand. Couldn't let mum know that I was even bleeding in case she asked why!
Touching the wires hanging out of the wall where the clock hung was fab, until I flew across the room and sat on the sofa unexpectedly. You really do learn respect for insulation at this point.
What? Why?
But these are not the lethal electric fences that you see in trashy science fiction movies.
These are specially designed to put out a high voltage pulse which gives a nasty bite, but is basically harmless.
I guess luckily I hit earth/ground with one of them - since we had differential (RCD) circuit breaker(s) installed it just shut off electricity in the apartment.
If I managed to hit both into real live and neutral - the differential breaker wouldn't have done a thing, and I wouldn't be typing this.
No guts no glory.
Obviously you don't laugh with big falls and broken arms.
But from my own childhood I can remember that kids are not subtle - if they are mocking you, you will know (names, finger-pointing, jokes, etc.). Whereas if a friend laughs with you about a silly fall, you get a completely different kind of scenario played out.
Coming back to your initial point, and being blunt: showing your children that clumsy falls can be funny, and not to panic about them, does not increase their cruelty towards other kids.
Everyone parents differently. I would be interested to see which culture the "laughing" reaction parents come from.
In my case, I taught them this by laughing at myself when I fall off my bike, so I am modelling the outcome I want--them learning to try things, fail, and laugh--rather than some kind of "do as i say" style of parenting.
But even falling off bikes can have an unacceptable worst case. So we insist on helmets. It is bad parenting to allow undeveloped brains to suffer avoidable and entirely foreseeable concussions when reasonable precautions like proper protective gear exists.
I think that sums up our parenting approach: Model the risk tolerance we want to encourage, including both taking risks and managing the consequences intelligently.
After that, it's up to them.
We need a fan, and optional air filter. Not sure what other options there are...
At various ages we wondered if the kids could put their fingers in and touch the blades, and so prompted them to (while the fans were off, of course).
At no point could the kids' fingers get to the blades. Either their fingers were too short, or, eventually, too fat.
It's noisier than expected, but on low it's quiet enough and fine for our entire house during "normal" bad pollution days (PM 2.5 between 100 and 300). During severe smoke from wildfires (PM 2.5 > 300), I'm OK with it being noisy.
But I got my refurbed on Woot for like, $100, not the $450 brand new they wanted, which is lunacy.
The dyson looked cool, but the heat function was kinda useless unless you sat right next to it. i might get another one without the heat.
The medify seemed to work well, but it felt like it was poorly made. I kept thinking I could probably diy something just as good. Though the main reason I returned it was because the advertising claimed it came with two sets of filters, when it only came with one.
I bought both of these last year after almost a decade of wanting to get an air filter, and not doing it. The whole industry feels like a scam. This is why I stopped shaving 20 years ago.
Coway Air Mega
Coway Mighty
Blue Air
Medify Air
They're basically all equivalent and they all work.
The reason I like the Medifyair is because it can move the largest volume of air relative to those so it can clear a space quickly (and quietly). I also think it looks nice (though it is huge).
Of the rest, the Blue Air uses weird custom filters which I think cost a little more (though I haven't had to replace them yet). The Coway Mighty is also pretty small and mostly for a tiny room.
Relatedly, if you're interested in sensors I think the TemTop sensors are the best (I've tried a bunch of different ones, and a lot of them suck).
Some details on this thread: https://www.reddit.com/r/AirQuality/comments/ikf1ed/are_ther...
For a modest house in the Bay Area during fire season, we needed a high MERV furnace filter and also two filters similar to their recommended models, so I moved up to the Medifyair. It arrived after the last fires, but it seems to work extremely well.
Hopefully, we won't need it this year...
https://news.ycombinator.com/item?id=25993512
I like consumer reports. You pay money for subscription and they provide you a non biased review.
I know the "you can never trust anyone who has affiliation links" argument, but if we follow that to its logical conclusion, Wirecutter should be strongly biased toward picks that give them the most money for referrals, and that's not really backed up by their choices. They pick cheaper choices pretty frequently, and it's possible to find picks where there's no apparent affiliate link at all, e.g., their pick for best "high-performance" subwoofer. One can posit, as was done in the thread you linked, that there might be deals directly with manufacturers that we don't know about, but "we can't be sure they're being underhanded without us knowing" doesn't actually get us anywhere useful -- the same could obviously be said about anyone, including CR.
In the review business it's better to be playing the long-term game if you're building a real audience. In Wirecutter's case their long term advantage is to make good reviews without regard to the affiliate payment.
There are already thousands of other websites that are just disguised ads. Wirecutter's differentiating features is that they don't do that.
They still have some reviews I think are pretty mediocre or products they chose that I think are bad, but generally I think they're worth looking at.
They make nonsense claims about their technology - none of which empirically hold up. They lie about it and are just generally full of shit, quoted below:
"In the summer of 2019, we purchased a Molekule Air (the flagship model) and tested it. We bought an Air Mini that fall and tested it in February 2020. At the time we tested the Molekule Air, the company claimed that its “scientifically-proven nanotechnology outperforms HEPA filters in every category of pollutant.”
Our tests proved otherwise. And by mid-2020, that language had been withdrawn, after many of the company’s claims were ruled against in a case before the National Advertising Division and upheld in a later appeal before the National Advertising Review Board. The Molekule Air turned in the worst performance on particulates of any purifier, of any size, of any price, that we have tested in the seven years that we have been producing this guide. The Air Mini outperformed it, but that’s not saying much: It still gave the second-worst performance we’ve ever seen.
Guide author Tim Heffernan asked Molekule CEO Dilip Goswami why the language was removed. He answered, “The point about ‘in all categories’ is that we see a device that outperforms across all of the categories. Right? So we’re not trying to say that individually, on any particular metric, we would be number one. Right? What we’re saying is, when you look across all the categories, we outperform HEPA. Right? And that’s what we’re attempting to convey with that. And so—it’s fair to say that we needed to re-examine some of the language to make sure that it’s saying what we’re intending to say.”
The NAD and NARB cases made clear that this was an understatement: All of Molekule’s quantified claims about the Air’s performance; all of its claims about superiority to HEPA; all of its customer and doctor testimonials about the ability of the Air’s filter to reduce asthma and allergy symptoms; and many of its claims to have been independently tested, were ruled unsupported. Other claims were ruled too broad."
"Dyson has developed its own testing methodology, the POLAR test method, which, unlike the CADR, Hill said, "measures the intelligence of the purifier, the ability for it to know when that room is clean or dirty and automatically react, and its ability to mix that pure air around the room."
The detection function seems of spurious value if the device is operating at max capacity regardless of whether a pollutant is detected or not.
Is that the case, or does the Dyson adjust volumetric flow to match the detected level of pollutants? That would make sense in the case of smoke, although humans could detect smoke and turn the device on or off accordingly.
COVID19 particles are a different case. If the Dyson can detect those and switch itself on, eliminating the virus from the room, $800 is a bargain. But it can't.
When I bought a purifier, one of the things I was looking for was air movement. I position my Dyson so that there's a draft throughout the apartment.
I thought this would improve the air filtration because the air would move through my home and eventually reach my purifier.
My previous experience with a purifier was a Honeywell tower that didn't move air. I noticed an improvement when I switched to a unit that moves air better.
Am I wrong? Should I give up Dyson anyway and choose another product?
My local costco has these units in store for $800 USD. Further down the isle they have oscillating tower fans for $30, and smart air filters for $100. I bought two pairs of each before winter. The fans are quiet, have plenty of control options, and non-volatle memory so you can use them with smart plugs. The air purifiers are 4 stage, with active charcoal and a long life (6 mo, 20$) hepa filter. They are wifi enabled, monitor and log air quality, and controllable from a phone. The purifiers should filter my bedroom's air once every 10 minutes, and ~15 min for my living room. This was all under 300$.
Edit: to answer your question, the regular dyson fans are great. They quietly and efficiently move air. Pointing one at a real air filter should really help the filter do its job. My issue is that dyson built a small filter into their fans and doubled the price.
My partner smokes indoor when I am not present and there's no smoke odor when I get home.
According to the chart on their app, the peak low air quality from several cigarettes goes away within an hour or so. https://imgur.com/a/0qgwT1F
There are definitely better units out there, but not for $100. That was the sale price at Costco when I got mine.
But once the sensors indicate that the PM2.5 is gone, everything is fine, right?
From what I can tell, PM2.5 isn't the end-all be-all metric and sensors can give false readings. That's why I'm building multiple devices with different types of sensors and monitoring multiple metrics. PM10 and PM1.0 are also concerns, as is CO and CO2. I am researching which VOC sensors to get because unfortunately not much info is readily available. But from the research I've read PM2.5 is the most prevalent and damaging in typical households (CO being a big exception, but that's also monitored by regular household CO alarms). I can tell when someone has been frying something in the kitchen from my bedroom sensor for example, and it lingers for a while. I can also tell when outdoor air quality is poor, and then my indoor air filter and closed windows do help. I am still learning about all this, but in general this data has been helpful to figure out when to open windows to avoid headaches.
I plan on publishing my findings at some point, but currently I am still waiting on parts and PCBs and working out the software to make it more usable without having to run to grab a USB cable to flash new firmware on the sensors. I was inspired by https://www.airgradient.com/diy/ but those plans are outdated and the dashboard is proprietary so less than ideal. I am working with simply integrating my sensor network with Home Assistant so I have to do very little with frontend stuff. It was very quick to set up notifications to my phone so I don't have to look at sensor screens all the time.
https://www.jaredwolff.com/finding-the-best-tvoc-sensor-ccs8...
I might play around with the BME680 but it’s VOC detection is very rudimentary and it does eCO2 which is basically a guess. There is also the MICS-6814 breakout for relatively cheap on AliExpress but reviews on it are mixed, saying it uses the wrong values for its resistors and capacitors and it’s not as accurate as the Grove one. The Grove board is the only one that measures separate gasses separately instead of measuring total gasses and then using a formula to try to divide the number down to expected parts.
In practice, who knows. I need to lay my hands on all of them. If I could get all this into a controlled environment to test it all that would really be ideal.
Thanks for that link, it was a great read and the comments were helpful as well.
Have you looked at open source smart vivarium projects? Several seem to have good front-end.
This may seem weird, but the reason I first started to explore air quality and sensors was to build a smart vivarium for a reptile.
I didn't go through with that project but it was a waking call for me. Animals need so much environment control to thrive and humans are animals.
So instead I focused on adding sensors and filters to my own home. Nothing fancy so far, just a mix of product that work with google home and smart sockets.
The biggest thing I found was that the PMS sensor has seen two generations of revisions. I built an original AirGradient and it’s sitting on my night stand currently but for new builds I am using a PMSA003 instead of PMS5003. Also I am substituting a DS-CO2-20 from Plantower for the CO2 sensor. That CO2 sensor seems to be well regarded and is slightly cheaper. And lastly I rewrote the drivers to be a bit different and a little more organized/readable/efficient. It doesn’t add much in terms of functionality, was just an excuse to write some C but I think it came out nice.
I redesigned the PCB to tie the PMS sensor’s SET and RESET pins to 3.3V per the data sheet. It seems to work fine without that with the PMS5003 but I haven’t yet received the new PCBs so I don’t know how it’ll work out. The PMSA003 has a different, slightly more convenient 1.27mm 2x5 connector so it’s easy to mount and get all the connections onto a PCB but isn’t breadboard friendly.
One other difference is that I’m not using a the Wemos OLED shield in favor of a stand-alone 0.96” OLED screen for double the resolution horizontally (your instructions show that one but not in the PCB build). And I wrote a different UI for it, plus added a button the PCB to do things like reset the sensor settings.
There are probably other things I’m forgetting but my email is in my profile if you want to move this conversation to that medium and once I polish up the code a bit more I am happy to share it. I will likely continue using these sensors with HA but I see no reason that you can’t use some of this in your work if you find it useful. I was planning on publishing the code and plans under a BSD license.
Overall, I wanted to thank you for the amazing work you did on AirGradient. I wouldn’t have been able to start on this project nearly as easily without your plans and code. It’s really impressive work very polished.
Examples
(I don't have the Honeywell anymore as it was my ex's)
This conversation makes me want to buy a second purifier and simply stop purchasing filters for my Dyson. That way, it would continue to work as a space heater and fan but the air purifying would be done by a dedicated device.
Makes sense as by rule of thumb, no "jack of all trades" devices will ever be better than a dedicated device. Hindsight is 20/20.
This sent the fan spinning at a weird angle and it hit the ceiling. This broke the wooden blades and sent them flying in all directions.
So floor fan it is now.
What I am describing is that the Dyson ends up doing a better job alone than the Honeywell did. Especially when it comes to the second floor. However, as you said one could quite likely achieve the same result with any air purifier and a strong fan.
Air filtration shouldn't be this expensive.
So long as it cycles the air frequently enough, eventually it will capture particles proportional to its basic filtration capability.
The Dyson filter is an open-air filter, that draws a small sample of the air through a filter, and passes the rest through unfiltered.
Each pass reduces the average (diffused) load of contaminants.
Two identically effective filters with different flow rates will eventually achieve a specified target diffused contaminant load in the air in the space; the only difference will be the time taken to achieve this (given a fixed initial contaminant load).
This should be clear...
"Despite no concrete evidence to support the concept, belief in fan death persists to this day in Korea,[further explanation needed] and also to a lesser extent in Japan.[1][2][3]"
Don't Use a portable electric fan in a closed room without windows or doors open to the outside. ... Don't Use a portable electric fan to blow extremely hot air on yourself. This can accelerate the risk of heat exhaustion. ... Don't direct the flow of portable electric fans toward yourself when room temperature is hotter than 90 °F."
Looking at climate data for the country, I was struck by how similar it is to upper Missouri. Saint Louis is about as humid, but a bit hotter on average. Which would make me suspect that if "fan death" was a thing, we'd be seeing it in a band of US States that're similarly hot and humid.
Speculative difference would be if air conditioning is really uncommon in South Korea, but presumably we could even that out by comparing to poorer people in the US.
I grew up believing in it (because my parents), and it took me a while to shake. At some point it became more of a superstition, but was still nervous to leave it on overnight...
There is, of course, the possibility that wincy's comment was meant to be tongue-in-cheek, though. I personally can't quite tell which way it was meant.
Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith.
I will note that people make arguments via questions pretty often in normal conversation, so that's not necessarily an accusation of significant bad faith. It could be more of a complaint about rhetorical technique.
But let's treat it as an accusation of bad faith. In that case, we have a deeper issue. Assuming that it's a real question asked in good faith is actually the weakest plausible interpretation, because the link makes it a self-disproving theory. Honestly the tongue-in-cheek interpretation is probably the strongest one.
There's no way to treat it as a strong argument and as a real question asked in good faith.
Also it can be okay to downvote misinformation even when the commenter didn't do anything wrong.
Saying "But what about x?" when you yourself provide a link that says that X is a non-issue doesn't make for an engaging discussion. "But what about x? This link suggests it's not a problem but I think it is because of y" does make for an engaging discussion, even if y is seemingly nonsense.
Maybe this person could even use the downvotes as a signal that there is something seriously wrong with their belief and learn something new.
I’m not Korean, but used to work at a company with quite a few second generation Korean Americans and we’d have Korean students studying in the US we hired as interns. They were very bright and very polite, but if we brought up fan death they’d say “oh haha yeah it’s funny... but it might be true”.
Lots of units will have a washable pre-filter, but that's to pick up big stuff and extend the life of the disposable part.
Dyson's stance on Brexit makes ever more sense... .
Aside from the “empty the canister out and watch all fine dust float back into my house” issue, vacuum bags function as one massive filter. It’s not physically possible to build a filter into a bag less vacuum that approaches the size or capability of the vacuum bag itself.
These days I have a roomba and a Dyson cordless stick vacuum for occasional use.
I ordered some from china (probably fake) for $30 rather than the $100 dyson wanted.
If an air purifier is generally accepted to be a higher-price item, then making a fan into one with some sort of filter helps justify the higher price.
(Just speculation, though. I have no info about their design or marketing decisions.)
Cheap vacuums are way better than they were. I bought a $60 upright at target for my office 5 years ago, it sucks (in the good sense) and is reliable. It does not have a ton of attachments, but it was $60.
For people with allergies this is a big selling point.
Panasonic used to also make great vacuums. Basically any canister vacuum will be well-equipped. Dyson is vacuums what Beats are to headphones.
To be fair, the Dyson outperforms it very minimally in suction (I'd say like 5% better) but that doesn't justify the near double price. Also the Roborock has a 'lock' button and a much better wall mount in my opinion. It's battery is Lithium-Polymer and cleaning the vacuum is easier.
Marketing is the only reason why anyone would buy a Dyson v11 over a Roborock H6.
Dyson fans produce a continuous stream of air. Regular fans produce choppy air. I don't think anyone actually notices this effect until you point it out though.
If you’re at a distance where you can talk into the airflow and sound normal, you’re probably not experiencing “choppy” air.
Yes, I found exactly that.
There is a company called QuietMark, I've bought fans from there and sent them back for being above average noisy, they're not interested in outside contact.
I recommend to buy and try for your own situation. Measurements of loudness are not the full story as the tone of the noise will interact in ways that can be unpredictably pleasant or harsh.
The Dyson fan issue is the audible motor whine at lower fan speeds (and with oscillation on, it creaks as it turns).
"If you need a quiet portable fan/filter find one that and has more than 7-8 speeds, preferably in double figures - and put it close to where you want the air, on low."
Ignore the price, cheaper may be better, but having many speeds suggests some sophistication and the option for lower speed means lower noise.
Obviously that's not how those numbers work, but you get the idea: it's not necessary to filter all the air at once.
2. The article says "15x more", so the right math would be 100x16/17=94.12 .
Fan X moves "15x more" air than fan Y. For every 1 unit of air fan X moves, Y will move 1x15 = 15 units. In the time it takes fan Y to move 100 units of air, fan X will move 100*(1/15) units, or 6 2/3rds units. 6.666... rounds to 7.