Dyson's original Air Multiplier, released in 2009, was the first fan to use brand new bladeless technology. Invented almost by chance, the totally novel invention nixed the revolving blades found on standard fans. Instead, airflow came from the base and was amplified in a loop before being pushed outwards. With no blades chopping through air, the fan produced a smoother, quieter breeze.
“It was a very tall order, completely new for us,” says Dyson engineer John Baptiste about the original Air Multipliers.
Revolutionary as the product was, it didn’t take long for consumers to point out that the so-called quiet fan wasn’t that quiet. So for the first real upgrade to the Air Multiplier, designers were tasked with making the fan as silent as possible, while maintaining an equally powerful airflow. And they did just that: the new models, released today, are 75% quieter than the first generation.
To get there, Dyson’s engineers deconstructed the original bladeless technology. They started by mocking up crude versions of a new fan that stood five feet tall and were padded with foam to muffle sound. In the process of exploring silencers, they came across the principle of the Helmholtz cavity. In a Helmholtz cavity, also called a Helmholtz resonator, sound gets reflected through hard, curved surfaces. The phenomenon explains why holding a seashell to your ear will produce a breathy, whirring sound, or why blowing air across a glass bottle top makes a hum. Noise is created through the Helmholtz resonator principle, but more importantly, noise can be meticulously controlled.
“It’s a classic way of addressing this sort of issue,” Baptiste tells Co.Design. “You can find them in car exhaust systems. Almost every car has this sort of silencer to attenuate the noise." Baptiste also says this technology is used in building acoustics, for structures like concert halls.
Previously with the Air Multipliers, a motor in the base was pulling in and releasing air, but "the air was not well managed,” Baptiste says. “When you’re not guiding it in the way you want it to go, it’s doing whatever it wants. It’s noisy.” Dyson’s engineers added a new cavity, with carefully calculated dimensions, that can mimic the Helmholtz principle and effectively silence the air that had previously ricocheted around in the base, thus significantly diminished the robotic hum that usually emanates from fans.
The price, however, is not diminutive: the new versions start at $299.