Copyright © Françoise Herrmann
Dyson’s famous bladeless Air Mutiplier™ technology is now 75% quieter! As a reminder, this is the fan with no visible caged blades, safest for kids and pets. The smooth circular opening of the fan is also easy to clean.
Air Multiplier™ technology consists of powerful impeller blades that are actually hidden inside the pedestal of the device. These function to draw in as much as 5.28 gallons of air per second through the base. The air is then diverted and forced through a small 1.3 mm opening and channeled at 55 mph through the airfoil of the hollow circular frame. As the air enters the airfoil of the circular airframe and exits through the 16 mm sloped openings around the rim of the annular aperture, it creates negative pressure, that draws more air in from the outside, at the back and sides of the annular ring. Thus, the air sucked in at the base is multiplied 15 times, as more ambient air is drawn in, and through, the annular ring.
The new Air Multiplier™ fans are now, also, almost silent. This new patented feature consists of a Helmholtz resonator cavity, the size of which is designed to neutralize the rotational tone of the impeller and to more generally reduce the noise level of the fan. The circular air circulation chamber is also designed to further reduce the ambient noise of the fan with noise suppression material. Thus, the powerful and multiplied airflow of the new fans is delivered with 75% noise reduction.
The Air Multiplier™ fans otherwise offer an oscillating or steady flow of the coooooolest unchopped air, on occasions where it feels impossible to get any fresh air via an open window, or to create a draft through the usual pathway between two openings, creating an open heat-exchange system. And for purposes, other than keeping cool (e.g.; during heat waves in locations without air-conditioning), quiet Air Multiplier™ technology is also combined and marketed with air-purifier, heater and humidifier functions, and most recently, in Dyson hair dryers too!.
The new patented noise reduction features of the Dyson Air Multiplier™ fan invention are disclosed and incorporated in a family of 15 patents, including the US patent application US20170108011, titled Fan. The abstract for this invention is included below with a patent figure drawing, showing a front sectional view of the fan, including the Helmholtz resonator cavity (156). A technical drawing of the Air Multiplier™ technology is also included above.
A fan for generating an air current includes a body having an air inlet, and a nozzle connected to the body. The nozzle includes an interior passage for receiving an air flow from the body and an air outlet from which the air flow is emitted from the fan. The interior passage extends about an opening or bore through which air from outside the nozzle is drawn by air emitted from the air outlet. The body includes a duct having an air inlet and an air outlet, an impeller located within the duct for drawing the air flow through the duct, and a motor for driving the impeller. A noise suppression cavity is located beneath the air inlet of the duct. The cavity has an inlet which is located beneath, and is preferably concentric with, the air inlet of the duct. [Abstract US20170108011]
Dyson Air Multiplier™
Herrmann, F. (2014) Oh, patents! The Dyson bladeless fan, posted at Patents on the Soles of Your Shoes, Jan 23, 2014)