It was just a few years ago that Dyson broke out into the mainstream, touting new wind tunnel technology and telling us all how our current vacuum cleaners were next to worthless. A lot of people scoffed at the design, but a quick look at store shelves today shows 90% of all new vacuums sporting basically the same technology (although not quite as well executed). Now Dyson has come back with another piece of new technology, and this time it’s our fans that he’s saying need to be redesigned. Read more on best tower fan here. If your house needs a new ceiling fan, you should also read our guide to the Airlight screw in lighted ceiling fan.

I know a lot of people see the man on the commercials as being cocky and arrogant (yes, you reinvented a vacuum – no, you didn’t invent something life changing), but you can’t discount the fact that his inventions work.  I’ve seen far too many bad ideas made into worse inventions that it’s nice to see something that works as intended.

At least for the most part.

But I’m jumping ahead – I don’t want to sell the positives of this thing short, so we’ll get to the negatives in a few.  I got to test out the 10″ model of the Dyson Air Multiplier (there’s also a huge 40 incher), and it was quite a treat.  You’ll notice from the pictures here, that you can’t see any blades – that’s one of the biggest selling parts of the Air Multiplier.  Rather than use blades (like a more traditional fan), the Dyson Air Multiplier has an impeller in it’s cylindrical base.  If you’ve ever seen a car’s turbocharger or a jet engine, then you’ve seen the same basic technology.

It’s not fair to call the Dyson Air Multiplier “bladeless” though – there are blades (that’s how the impeller works), you just don’t get to see them.  There are actually nine asymmetrically designed blades in the housing, that rotate to draw in just over five and a quarter gallons of air a second.  That air then flows through the hollow “ring” section and out the back (the interior of the ring acts almost like a ramp).  Once the air is flowing out, the rest boils down to a quick physics lesson.

Warning: science content coming next

The atmosphere all around us is comprised of various gasses, and all gasses obey the physical laws of fluid dynamics.  As the air is pushed along the ramp and out to the front of the fan, air behind the fan is also pulled along for the ride.  This phenomenon is known as inducement. The air that is being pushed out by the impeller induces the air behind the fan to follow suit.  At the same time, the air that is located around the edges of the fan will also begin to flow in the same direction of the breeze.  This happens because of the friction the air coming from the fan causes (Dyson says when it leaves the ring it moves at around 55mph).  This phenomenon is known as entrainment.  Because of these two phenomenons, Dyson claims that the Air Multiplies increases the air coming out by fifteen times.

The challenge of getting a large volume of air to move through the fan solved, Dyson then had the problem of making sure the air flowing in the stream kept moving smoothly (having to balance the speed or inertia of the air, with how viscous it is).  Luckily though, physicists have an equation that represents this balance; this equation results in a number called the “Reynolds number”.  Plugging numbers from Dyson into the formula (a 55mph air flow, a 1mm width stream, 1.2kg/m^3 air density, and 18.27 * 10^-6 Pa s viscosity) gives you a Reynolds number of 1615 for the Dyson Air Multiplier.

O.K., science content is over

If you’re still with me after all of that, I’m sorry – it’s just without the background, you can’t really grasp how well it works.  This thing churns out are like no one’s business.  It does have two glaring flaws though – one is really expected from Dyson though.  The expected flaw is the price.  $199 for a small fan just seems absolutely insane to me.  Granted, it makes for a pretty neat conversation piece (I’ve had people ask about it numerous times now), but still that’s the price of an air conditioner.

The second major flaw with the Dyson Air Multiplier is the fact that the thing sounds like a jet engine taking off.  If you usually use a fan for white noise to fall asleep to – forget it.  Yes, the Dyson Air Multiplier costs the same as an average 6500 BTU air conditioner, and it also sounds as loud (if not louder) than said air conditioner.

In short, if you don’t mind spending some extra cash for new tech – give the Dyson Air multiplier a shot.  It does what it’s supposed to, and it does it quite well (albeit extremely loudly).  I’m sure that just like their wind tunnel technology there will be copy cats in a few years, and everyone will have similar fan designs.  I give the Dyson Air Multiplier a final score of four stars out of five.  It would be really great for people with small children since there’s no external blades to get injured on.


  • Very easy to clean and maintain
  • It moves a hell of a lot of air for it’s small size
  • Very futuristic looking – makes for a great conversation piece


  • The noise that it makes could probably wake the dead
  • The price is extremely high for a small fan
  • Need a physics degree to actually understand how it works

You can get the a Dyson Air Multiplier of your very own from Amazon for $199.00

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  1. We bought the AM01 10″ table fan today. It worked for six hours before quitting. When it quit the blue power light started blinking. We switched it off, unplugged it and waited ten seconds before plugging it back in and switching it back on. The power light was a steady blue for about two seconds and then it started to blink. The fan would not turn on. We will be returning it to the retailer for a refund. We were surprised and disappointed after spending a small fortune on this fan to have it fail on the first day. Our three year old twenty dollar offshore fan goes back on the table until we find a suitable replacement. It is doubtful that we will risk spending that amount of money on this type of fan again.

  2. Without explaining the Reynolds number that paragraph is meaningless.  Most people have never taken a fluid dynamics class or have any sort of physics back ground.  The Reynolds number has a unique meaning to each fluid it is calculated for and used to define what stage the airflow is in, laminar, transitional, or turbulent.  These types of flow are defined by a range of Reynolds numbers.  Laminar is the lowest range, then comes transitional, and finally turbulent.  These ranges also can vary with the nature of the flow, over a flat plate, within a tube, around a cylinder, or over a bank of tubes.  I am not personally familiar with the Reynolds number ranges for air or what type of flow this would be exatcly, but I believe it would be helpful to at least explain that a laminar flow is desireable.  I understand this is a review and there is no need to get in depth in the technology, but I believe bringing it up warrants an explanation. 

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