Re-engineering Cool: how Dyson improved its fans

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To coincide with the beginning of spring, Dyson has released its next-generation Cool range of fans in Australia. Design engineer Thomas Ting tells Brent Balinski a few things about how the company improved its bladeless fans.

 

High-end home appliance company Dyson has drastically changed what consumers expect, and often by removing rather than adding to how a task gets done. Whether it’s been by removing bags from vacuums or paper towels from the act of hand sanitation, success has often involved removing rather than adding.

This time around its Dyson Cool bladeless fans remove the vast majority of noise – and significantly remove the energy required – from the product range introduced in 2008.

The original Air Multiplier offering was designed as a desk fan, without the expectation that the device would be put to its full-blast setting.

While the fans did their job admirably, without the choppiness of regular fans, the volume of the product at the maximum setting was an area that could be improved.

“Because of this James Dyson issued an engineering brief to the engineers to come up with the next generation of fans that would be quieter, more energy efficient and also with no compromise to performance,” explained Thomas Ting, a design engineer at Dyson in Singapore.

Ting joined the company as a graduate engineer. He remembers saying “Wow; I have to work for this company” when he saw a first-generation Air Multiplier fan at a Tesco’s while studying Advanced Mechanical Engineering at Sheffield Hallam University.

He got back to Singapore and joined as a team member focussed on the wall brackets (housing the device’s electronics) for the Airblade Tap, released early last year.

“I spent a lot of time spraying jets of water at the wall brackets,” he told Manufacturers’ Monthly of tests his team carried out to check IP57 standards were being satisfied.  

Dyson carries out the bulk of its considerable R&D operations – budgeted at about $4.5 million a week and involving 1,600 scientists and engineers around the world – in the UK.

Prototypes are then often transferred to Singapore, with designing for the limitations of manufacturing methods then considered.

“Then what we do is we look into tuning the internal components,” said Ting, who worked with a team of five – senior engineer, three design engineers and one graduate engineer – this time around. His team’s responsibility was the motor bucket.

Key concerns included reducing turbulence inside the fan, whose upgrade had around $75 million and a total of 65 engineers devoted to the task.

“First of all you get 75 per cent less noise,” explained Ting of what the increased efficiency has meant.

“Secondly it requires less energy to push the same amount of air through the Air Multiplier.”

Compared to the first generation AM01, an AM06 on display at the product’s launch draws in 21 watts at its highest setting (compared to 33 watts).

The machine’s impeller and brushless motor draw in air and expel it at high velocities out of the hoop, creating a very low pressure region around the front.

The block of air being drawn through the loop creates viscous shearing, where more air from the surroundings is being continuously drawn (up to 18 times).

“The impeller is, for example, drawing in 20 litres per second of air, what you get – the amount of air you get expelled from the loop is closer to 300 Litres a second,” said Ting of the process that inspired the product’s name.

The new AM includes a smoother airflow path and improvements dampening the sound around the motor.

“Even something as simple as the welding of the impeller is something we tightly control,” he said.

“It’s a combination of many, many parts. It’s not just that you improve one single component and you see a 30 per cent improvement [overall].”

Another improvement was the addition of a Helmholtz Cavity, which dissipates high, whining frequencies of around 1,000 Hz (equivalent to the beating of a mosquito’s wings).

A little bit of foam here, some curved plastic there (all in meticulously engineered dimensions and using a principle used by acoustics engineers in concert halls around the world) and the mosquito-like hum was gone.

“We improved the overall tonal quality of the fan,” noted Ting.

There were no fewer than 640 prototypes along the way to improving the Air Multiplier. The iterative improvement process follows examples including, most famously, James Dyson’s 5,127 prototypes before he was satisfied with his bagless vacuum cleaner.

The new line of Air Multipliers have only just been released in Australia, though earlier won a Best In Category award for domestic appliances at the Good Design Award in May.

The company hopes successes this time around will also include healthy sales as the Australian summer kicks in.

 

More information on the Dyson Cool fan range can be found at http://www.dyson.com.au/