

Dyson's overpriced fan and the Coandă Effect  - jgrahamc
http://www.jgc.org/blog/2009/10/dysons-overpriced-fan-and-coanda-effect.html

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mseebach
Give it a break.

> The Coandă Effect is very well known, and Dyson hasn't invented something
> revolutionary here

When someone does this to a startup, this place is ripe with "screw the idea,
it's all about execution" and "any sufficiently advanced technology is
indistinguishable from magic".

I salute Dyson for putting simple physics to work in simple, yet aesthetically
pleasing fashion.

In other words, if it's so easy, why aren't YOU selling a £200 Coandă effect
deskfan?

~~~
jgrahamc
I think you are reading too much into that statement. The Coandă Effect was
well known and all I claim is that Dyson didn't invent it. My other claim is
the £200 is a lot for a fan no matter how cool the technology is.

 _In other words, if it's so easy, why aren't YOU selling a £200 Coandă effect
deskfan?_

I never claimed it was easy, you also edited my blog post to remove the bit
where I say _(although I assume the engineering is very good)_.

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maukdaddy
If the market will support it, £200 is not a lot for a fan ;)

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foldr
Eh? That's like saying, "if the market will support it, $2000 isn't a lot for
a pair of jeans." Just because enough people are willing to spend $2000 on
jeans to keep the company in profit doesn't mean that they're not expensive.

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cwan
We've made something similar for industrial use. My understanding (given that
we only do the machining) is that in an industrial setting they require loud
compressors with much larger footprints... so the real engineering feat is
probably the motor depending how loud these suckers are
([http://www.engadget.com/2009/06/29/dyson-speeds-up-worlds-
fa...](http://www.engadget.com/2009/06/29/dyson-speeds-up-worlds-fastest-
motor-gives-it-some-fancy-pac/))

~~~
jgrahamc
The motor is interesting since it's a "digital" motor called a Switched
Reluctance Motor: <http://en.wikipedia.org/wiki/Switched_Reluctance_Motor>

~~~
jws
I think this might be the real story here. Google about and you will find
articles from 2003 talking about this nifty 100,000rpm switched reluctance
motor and impeller combination that Dyson's people were working on. I think
the air mover is just an answer to "so what do we do with it?"

I still want someone to say what the air mover sounds like. 100,000rpm should
put all of the sound energy above 1,500Hz, and higher frequencies are easier
to damp, so it is possible the thing is quiet. On the the other hand, the ad
copy doesn't say "SILENT!!!".

------
est
It's not overpriced, Dyson has to be quick making some money before the
Chinese copy it and sell derivatives on every corner of the solar system.

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louislouis
Pricing it anythng lower wouldn't tie in with the Dyson brand. Could you
imaging if they were selling these at £20, who then would want one? Everyone
who needs a fan already has a fan. But if you have one of these £200 toys sat
in your house, you're sure to look cool and feel cool with that fanless air
blown in your face.

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joshwa
My personal favorite reference to the Coandă Effect involves urinals:

[http://www.straightdope.com/columns/read/2450/urinal-101-aim...](http://www.straightdope.com/columns/read/2450/urinal-101-aim-
for-the-back-wall-or-the-water)

<http://ask.metafilter.com/8204/Urinal-Aiming#160007>

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bonsaitree
The in/famous Dyson branding aside, I'd like to measure the fan's volumetric
efficiency per watt compared to a conventional inline blade design.

In other words, how much air is moved at what speed given the electrical
energy expended to drive the impeller.

I doubt seriously that it's much better than conventional fan designs given
that it has 3 distinct regimes of airflow (intake duct, impeller blade, Coanda
foil).

Additionally, though inline impellers can be quite efficient, having these 3
distinct vector flow regimes will bleed energy in de/compression inlet/exhaust
artifacts (noise and vibration) so it won't be much quieter than a
conventional design.

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KevinMS
Ok, I found this video linked from their site, and I'm not sure if its a joke.
Skip to when he turns the fan on, about 1 minute in.

[http://www.youtube.com/watch?v=U1ZcpCY2O6k&feature=playe...](http://www.youtube.com/watch?v=U1ZcpCY2O6k&feature=player_embedded)

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Retric
I think it's false advertising to say it has no blades. It uses an internal
fan that you can't see to push air.

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swombat
You're just being overly pedantic. To most people, it has no visible blades,
and therefore it has no blades.

Sure, a more accurate wording would have been "no blades that you can stick
your fingers in", but you can't expect too much out of marketing people!

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unalone
Marketing people aren't dumb. They just know that consumers _are_. "No blades
you can stick your fingers in" is accurate, but buyers want catchy and
memorable, even at the cost of slight factual inaccuracy.

~~~
lnguyen
And that's how a quote like "the greatest piece of sh*t of a movie ever"
becomes "the greatest... movie ever" in an ad

~~~
unalone
Yep! You can blame marketers, but that's their job, and it works. Until
society becomes a lot smarter and more cynical, people will be paid to make
things popular, and they'll do a lot of really obnoxiously cheap things, and
it'll all work.

