I'd actually expect the tornado to work a little if the intake is straight and less than a foot long. Any longer intake, or any bends and the swirl is gone. Since none of us have such an intake, it will restrict flow.

The theory is similar to - Inlet Guide Vanes Reducing Power Consumption on a Centrifugal Fan ...... which I have personally proven. The gain is very small on a very large fan. I'd have to dig up my college lab notes to tell how much power was saved.

 

What's this crap 100 bucks. There's another brand out there on ebay that sells them for 40.

 

http://www.technologyreview.com/Energy/19412/

Check this out. Maybe we were too quick to dismiss magnet power! Tongue is firmly in cheek here

Regards