How Does the Dyson Air Multiplier Work?
Bladeless Fan Baffles OnlookersBy Robert Cong
Product Marketing Engineering Manager
Imagine a reverse vacuum cleaner that generates airflow of up to 55 mph. For most people who've seen the Dyson Air Multiplier, the first thought that popped into their heads was "That's really cool", the second was "How does that air multiplier work?" Given the ultra-modern design of this device, it's easy to wonder about the process that makes this "fan" function.
The Dyson Air Multiplier is a bladeless fan that provides a smooth flow of air, much like that of a constant wind breeze. It has a futuristic look very much different from traditional fans and as we found out, it works much differently as well.
Although it is called a "bladeless" fan, the Dyson Air Multiplier does indeed have blades within; they're just hidden inside the pedestal stand. This is the section of the fan that draws in up to 5.28 gallons of air per second, as much as a vacuum cleaner!
In addition to the blades in the pedestal stand, the air multiplier also makes use of a brushless electric motor, which rotates the nine asymmetrically-aligned blades. This provides for precise control of the speed of the fan, while staying relatively quiet compared to brushed motors. The pedestal motor adds extra push to the fast flowing air and shoots it up into the ring portion of the fan.
The air flows through the channel in the pedestal, through a curved path, and comes out from small 16mm slits around the frame of the fan at a 16-degree angle slope. You may think that this just causes air to blow in the shape of the surface area of a cylinder, but because of the physical laws of inducement and entrainment, this allows for the surrounding air to also become drawn in from multiple areas around the fan. In other words, picture your TV weather map; a small low-pressure region is created which actually draws the air in from behind it, like a forming tropical storm. This simultaneous push and pull of air creates a quiet, even, constant flow of cool breeze.
Making use of these laws, Dyson claims that the output of airflow is increased 15 times more than that taken in through the pedestal's motor, thus the name: air multiplier. The result is a filled cylinder of air flowing smoothly without the choppiness of traditional fans. The price range may be a little beyond the normal price for a fan and some users have claimed that it can be rather noisy, but the Dyson Air Multiplier provides an eye-pleasing, low power consuming fan that is safe to use around young children due to the lack of accessible rotating blades.
The reviews we've seen rave about the technology but grumble about the $199 price tag and the jet engine noise, but as connoisseurs of technology we love this new approach.
Check out this cool video done by Dyson's engineers demonstrating the laws of inducement and entrainment.
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Robert is a graduate from Cal Poly, San Luis Obispo in Electrical Engineering. His interests include sports, movies, music, and playing with cool, new gadgets.