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Innovative engineers at Dyson reinvent the fan

Woman controlling a fan with a switch
If you use a ceiling fan to help keep your home cool, run it counter-clockwise in the summer.

How Dyson engineers redesigned their groundbreaking fan to be more efficient, and quieter too

Most of us do our best to be more aware of the energy we use so we can be more efficient in how we use it. That's true for technology companies, too, in their work to invent new machines and to improve old ones. Refrigerators and other major appliances that are in stores today require much less electricity than models from ten years ago.

Rob Green is a senior design engineer for Dyson. In an interview from the Wiltshire, England headquarters, he explained that while the first priority at Dyson is performance, designing for efficiency is always a factor.

"In engineering, the sign of real progress is when you get something more for less input," he explained. "It's easy to get a powerful machine if you just whack a big, heavy, powerful motor in it. It's harder to produce an equally powerful device that's smaller, lighter, and more energy efficient."

But the drive to do just that is what led to the Dyson digital motor, which powers the company's cordless vacuums as well as the larger, full-size models.

Dyson recently released a new version of its groundbreaking, blade-less fan, and Rob talked about how, and why, they did that.

Fans are inefficient by design

What fans do is move air around, something Rob says is inherently inefficient because doing so creates turbulence and air resistance. The regular fan, with blades that rotate and pull/push air, are bulky and noisy. The plastic and metal cages that surround the blades are a feature that have been standard for less than a century, and while they make fans safer, they also make fans difficult to clean.

Rethinking the standard fan

Dyson engineers created "Air Multiplier" technology while inventing the Airblade hand dryer that are in many public washrooms, including Science World. Rob said that in experiments, they noticed that more air was coming out of the machine than was being pulled in. What the engineers realized was that when air was leaving the machine at high speed, it was resulting in an area of low pressure around it, which was pulling extra air with it.

That's why the Dyson fans have loops. When air rushes out of the ring, it pulls additional air through the loop with it. And because there are no blades on the fan, the air flows smoothly, not choppy.

"But we weren't only looking at energy efficiency," said Rob. The Air Multiplier fans also required fewer raw materials and energy to manufacture, and was much lighter so cheaper to ship.

Making the new fan design better

As great as the blade-less fans were, Rob said that Dyson wanted to try and get as close as possible to eliminating the inefficiencies that result from moving air.

According to Rob, Dyson engineers created 640 prototypes and conducted 1,550 tests while making the fan better. "The biggest challenge was to move the same amount of air while reducing turbulence and air resistance," he said. "Less energy wasted means a more efficient machine."

"The air now takes a shorter journey through the machine," said Rob, "giving it a higher airflow rate and greater energy efficiency." And a new motor in the fans requires less electricity.

All of this means that the new Air Multiplier fans consume up to 40 per cent less electricity than the earlier models. And they are 75 per cent quieter.

Other ways to keep your house cool in the summer

As the weather heats up this summer, fans are only one way you can keep your home cool.

Others include: