When designing the airblade hand dryer, which dries hands by forcing air out of a .3mm wide slit at over 600km/h to effectively squeegee the water off your hands, Dyson noticed that a huge amount of additional air was being drawn into the process.
Frustrated with the traditional fan, which creates buffeting by slicing at the air, and the inherent dangers of fan blades spinning around, Dyson investigated using the effect he noticed with the hand dryer to move air in other ways.
The bladeless fan forces air through a 1.3mm slit on the inside of “the ring” and out the back.
Only 7% of the air pushed out by the bladeless fan comes from an impellor (which has unevenly spaced blades and holes drilled into them to reduce noise) – the rest is drawn in by creating a negative pressure area within the ring and forcing it out backwards.
There are two stages of negative pressure, which work together to “multiply the air” – the first is a traditional aerofoil design (low pressure surface, or lifting surface, inside the ring) and the second stage is actually just a twist on a traditional aerofoil with a 15 degree slope which actually draws air in from the back. There is actually also a third stage of “air multiplication” which uses an effect called viscous shearing, which is used in jet aircraft to reduce noise, to further multiply the amount of air being forced backwards.
Effectively the original airflow is multiplied 16 times through physics. cool!
Even the tilt function of the Dyson AM01 rotates around the center of gravity of the fan.