The propeller is quietly being reinvented, in both marine and aviation. The new invention is toroidal propellers that move more efficiently and quietly through both air and water. A company named Sharrow Marine is poised to start selling toroidal propellers to replace traditional twisted-aerofoil bladed props that have been used for thousands of years, going back to Chinese toys, 2,400 years ago.
The MIT Lincoln Library has also been researching super-quiet, 3D-printed toroidal propellers for commercial drone use. See the images below. The MIT lab is getting dramatically reduced noise from their toroidal propellers, especially in the 1-5 kHz frequencies that are most annoying to people.
Sharrow Marine has demonstrated marine propeller efficiency improvements of 5 – 107% depending on rotation speed (RPM). Those are remarkable improvements.
All of this has me wondering if the benefits of toroidal propellers would create more efficient ceiling fan blades. Of the two examples, the drone propellers are the better example of what new toroidal ceiling fan blades could look like. While I can’t predict what the efficiency gains would be, nor the noise reduction, it would likely produce improvements in both, however that are RPM dependent. There has been regulatory pressure for ceiling fans to improve efficacy through DC motors, which are expensive. Would it be possible to achieve these efficiency gains through lower-cost toroidal propellers, instead? Could the combination of DC motors and toroidal propellers create radically more efficient ceiling fans, with significant miniaturization and cost reductions?
After searching for toroidal ceiling fans online, the only design that looked similar was the Willacy by Progress Lighting. It doesn’t claim to be toroidal, however. See the image below. If you’re aware of any research in applying toroidal propellers to ceiling fans, please share in the comment section below. More information on toroidal propellers for marine and aviation is available here.
Read more articles about research in the lighting industry here.