“Inducement and entrainment” of the air? That sounds like the same crap pushed over the years by the Coanda enthusiasts.
In fact, the Dyson fan moves a small fraction of the air of a similarly powered conventional fan and is much noisier according to the reports. As far as the air buffeting is concerned, it simply isn’t an issue unless one is really close to the fan since the air stream quickly smoothes out.
The Coanda based flying machine promoters have used exactly the same arguments for efficiency because this is basically a Coanda device. The principle has been successfully used on a hi-end range hood but that is another thing entirely. http://www.ajmadison.com/cgi-bin/ajm.../AH360720.html
The efficiency claim for the Coanda devices is based on a report of a wind tunnel test done at IIT (Illinois Institute of Technology) which just happens to be my alma mater. I have read that report and it was clear that the ‘aerodynamist’ violated the most basic of procedures by sticking his hands into the air stream, grossly modifying the flow over the test body and distorting the balance readings (his hand affected and accelerated the flow but obviously was not connected to the balance, thus any drag produced on his HAND would not be measured). This test was blatantly unscientific yet the Coanda nuts have latched onto this wonderful fiction (I know one all too well and try to avoid him since he insists on talking about this every time he traps me in a social setting).
I have seen youtube clips of several little Coanda models and they barely can get off the ground. Compare them to any of the little helis you see at the local field doing amazing things at warp speed and it is clear which technology is best.