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Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

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Re: Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

#261

Post by akeck »

nvarsj wrote: post #243

Is there any point to air purifiers at all? I remember researching them a while ago as a way to alleviate my allergy symptoms without medicine. But the overall scientific consensus seems very dubious. To be frank, it seems like yet another one of those very expensive placebo products that rich people like to buy because of media scare mongering. I can see the obvious exception being a heavily polluted eastern city -…

It's been easier for me to focus during WFH when my HEPA filter is running, so I think it depends on the person and the location.

Re: Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

#263

Post by UnFleshedOne »

sorenjan wrote: post #211
reaperducer wrote: post #124

Earlier quoted context omitted.

Pretty much every Dyson product I've used, from the public bathroom air "blades" to the vacuums, seem like a gimmicky, inferior products with a premium price tag That's interesting to me because I've had the opposite experience. I move a lot. For almost decade I moved twice a year. I don't like taking the dirt from one place to the next, so I buy a new vacuum cleaner every time. So I've been though a lot of vacuum cl…

> I don't like taking the dirt from one place to the next, so I buy a new vacuum cleaner every time. That seems extremely wasteful. Why not just emptying the vacuum cleaner before bringing it to the new place? One person buying 20 new vacuum cleaners in a decade is just one of the reasons this planet is running out of resources.

Especially considering that 80% of the dirt the vacuums collect are his own skin flakes and hair anyway...

Re: Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

#264

Post by danans »

Some of the best air filtering systems (and also among the most expensive) are systems like the IQAir [1], which are essentially boxes with a fan at one end and a series of filters arranged in an alternating diagonal pattern:

  Note: / and \ are each separate filters

            Filter
             box
             ___
            | \ |   
  Inflow -->  /  --> Outflow
            | \ |
            | / |
             ‾‾‾
This maximizes the filtration while reducing the static pressure, since the filtration is distributed over a large surface area.

Of course a lot of the high cost of installing such a system is the whole-house ducting. They also make single room purifiers, but there are also not cheap [2].

1. https://www.iqair.com/us/whole-house-air-purifiers/perfect16

2. https://www.iqair.com/us/room-air-purifiers/healthpro-series

EDIT: Corrected orientation of diagram

Re: Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

#265

Post by kixiQu »

crmd wrote: post #82
AlexandrB wrote: post #3

Dyson : Air Products :: Beats : Audio Products Pretty much every Dyson product I've used, from the public bathroom air "blades" to the vacuums, seem like a gimmicky, inferior products with a premium price tag. None of them do their intended job better than older, cheaper products in their category. I know James Dyson is regarded as a genius engineer, but the consumer product company bearing his name seems to be 99% m…

Check out AvE’s tear down of a $500 Dyson hair dryer.[1] He was expecting to ridicule it but was instead blown away by the engineering - tiny high torque zinc cast brushless DC motor, CNC-milled impeller, etc. It’s a good watch, including FLIR performance analysis, Fourier analysis of bearing noise, and more. In summary it’s definitely more engineering porn / extreme overkill than marketing bs. [1] https://youtu.be/j…

Yeah, I'm pretty sure the people saying "they have no good products" or "their only good product was a bagless vacuum" do not have adequate hair dryer experience to be making that judgment. It's interesting how quickly commenters are assuming that the target audience is incapable of evaluating performance when it doesn't take an air particulate sensor to do so.

Re: Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

#266

Post by ahaucnx »

I am living in Northern Thailand that goes through the annual smoke season with often US AQI beyond 300 and in the Hazardous area. That experience lead to the foundation of my startup AirGradient [1]. More and more people here are moving beyond air purifiers and install positive pressure systems in their house, offices or schools. Positive pressure systems take the outside air, run it through a set of high performance filters and pushes it inside the rooms. This has mainly two significant benefits:

a) The positive pressure prevents dirty air from entering the room in the first place. As a results you become totally independent from the outside pollution and you can achieve zero PM2.5 inside even on the worst polluted days. I made a performance comparison between a standard air purifier and a positive pressure system and the positive pressure system won by a huge margin [2].

b) Low CO2. If you use normal air purifiers you are in a catch-22 situation. In order to get good results you need to keep your doors and windows closed. This leads to a very fast build up of CO2 in a room. High CO2 levels significantly impair cognitive performance and can lead to drowsiness and headaches. We measured the CO2 in classrooms [3] and very quickly you will see CO2 levels beyond 3000ppm (most Standards recommend levels below 1200-1500ppm).

Against Covid transmission prevention, the best setup would probably be a combination of positive pressure system (to ensure a constant ventilation rate) together with a recirculation unit (standard purifier) inside the room to trap aerosols with viruses.

We have open-source open-hardware build instructions for a DIY air quality sensor measuring PM2.5 and CO2 [4]. I am more than happy to send you some free PCBs (you just paypal me the cost of the postage) and you can build your own sensor and log the data. Contact me if you are interested.

[1] https://www.airgradient.com/schools/

[2] https://www.airgradient.com/blog/2020/03/30/air-purifier-vs-...

[3] https://www.airgradient.com/blog/2020/02/07/we-measured-the-...

[4] https://www.airgradient.com/diy/

Re: Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

#267

Post by alasdair_ »

gonehome wrote: post #206
ortusdux wrote: post #4

I still cannot get over this product. They whole selling point of a dyson fan is the 'air multiplier' tech, which creates a low pressure zone that propels air through the ring. According to dyson, this tech can move 15x more air than the fan in the base of the unit. Why in the world would you build an air filter around a system that does not directly interact with 93% of the air it moves? https://www.jameco.com/Jamec…

The fan also sucks compared to something like a Vornado. "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…

We bought a Dyson fan when we had very small children that liked to stick their fingers into moving fan blades. It works really well for that purpose.

Re: Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

#269

Post by LegitShady »

adamscybot wrote: post #189
LegitShady wrote: post #106

Earlier quoted context omitted.

I prefer the Excel XLERATOR hand dryers, and usually spec them over most other models. Hands dry in ~10 seconds, not spashing onto a lower surface, etc.

Yeh, those are good. Though they seem to have appeared shortly after the Dyson blade dryers. Dyson seem to have shaken the market a bit into realising you actually need power in these things for them to be useful.

No, the XLERATORS predate the dyson airblade by ~4-5 years. The dyson just made people realize that they were more expensive than the garbage units people used before, but not that expensive.

Re: Dyson air purifier outperformed by cheap DIY box fan filter in Marketplace test

#270

Post by ihuman »

ortusdux wrote: post #219
u678u wrote: post #194

Earlier quoted context omitted.

I think its a good quality fan and a fan heater that also purifies. Purification isn't its only goal, so if you care only about that just get a purifier. Presumably the cheap DIY box did a bad job at heating the air.

Check out dyson's website. They don't even list fans on their product page. It's just variations of air purifiers. They are all advertised first and foremost as purifiers. https://i.imgur.com/GaYU6ZD.png https://www.dyson.com/air-treatment

I don't think they sell the non-purifier ones anymore. Google searching led me to a page with a mix of purifier and non-purifier fans [0], but the links either bring me to the "air-treatment" section or break completely.

[0] https://www.dyson.com/fans-and-heaters

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