The Invention Of The Bladeless Fan

Dyson made a big splash in 2009 with the release of bladeless fans. If you were to stop by any electronics store, you would likely see that the majority of bladeless fans being sold are still Dyson models. The United States Patent and Trademark Office even credits Sir James Dyson and a group of his engineers with the invention, so you would be forgiven for assuming they created the technology, but as with everything, looks can be deceiving.

According to documents at the Intellectual Property Organization (IPO), Toshiba originally submitted and received a bladeless fan patent in 1981. They even denied Dyson's first patent claim in 2009 because, as they said in their initial ruling, the Dyson version "cannot be considered novel or cannot be considered to involve an inventive step."

Dyson had to resubmit another patent attempt, which highlighted a key design feature known as the Coanda surface. The air in Dyson's bladeless fans is pushed out over an aerofoil ramp, which is the Coanda surface, and, because of the angle, additional air is sucked in and it creates a smoother and more powerful air stream. This additional design feature was considered enough of an improvement on Toshiba's technology for Dyson to receive a patent.

How A Bladeless Fan Works

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While the bladeless fan, or Air Multiplier as Dyson calls it, doesn't have any visible blades, it does indeed use blades to create air movement. In the pedestal, there is a brushless electric motor, which contains nine asymmetrically-aligned blades that rotate and pull air into the unit. This tiny little motor can suck in roughly 20 liters of air per second.

Once the air is introduced into the system, it flows through a tunnel in the pedestal and up to a hollow tube that acts as a ramp. The air then flows through the tube and comes out from tiny 16mm slits around its frame at a 16-degree angle. Due to the physical law of inducement, the flowing air being pushed by the motor induces air behind it to follow.

Due to the law of entrainment, the air surrounding the edges of the fan also start to flow in the direction of the breeze. A low-pressure area is created inside the hollow tube, which sucks in even more air through multiple strategically placed areas on the fan. All of this adds to the original amount of air introduced into the system via the motor in the pedestal.

The simultaneous push and pull of air produce a constant flow and, according to Dyson, can even increase the output by 15 times the amount that is taken in through the motor. While this unique fan design produced an incredible amount of air flow, it did have one main drawback - it was exceedingly noisy.

There was a lot of turbulence created by the air being sucked into the base and bouncing around in the pedestal's chamber. To solve this, Dyson integrated a Helmholtz cavity into the base. Their efforts resulted in a 75% reduction in sound and also allowed them to significantly scale back on the motor size because of the increased efficiency in air flow.

Benefits Of A Bladeless Fan Over Standard Fans

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For those of you considering purchasing a bladeless fan, it might be hard to justify the cost, but they have a number of benefits over traditional fans. First off, the air is moved in a much smoother pattern, which creates a more consistent flow.

This results in two advantages over conventional fans. It is more relaxing to sit in front of one as the stream of air is less choppy and feels more comfortable against the skin. It also increases the fan's cooling ability as you will have continuous airflow coverage.

With the addition of the aforementioned Helmholtz cavity, bladeless fans are nearly silent now. Even sitting right beside one, you probably won't be able to detect any noise and, if not for the cooling stream of air, you wouldn't even notice the fan is on. For those of you who find the loud hum of traditional fans annoying and distracting, a bladeless fan is definitely worth the price.

If you have a curious small child running about your house, a bladeless fan can be significantly safer as there are no external moving parts. They are also surprisingly durable as well, despite their fragile, artistic look. You don't have to worry about blade edges hitting the fan guard if you hold it at the angle or accidentally knock it over while it is running. It's also hard to overlook the stylish design of bladeless fans and, unlike conventional fans, they will often add to your decor rather than detract from it.