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Desite your reply as an AC, I have to give you credit for correcting me on this one. You pointed out something that I did miss. I did recognize that the Coanda effect was redirecting the airflow downward around the edges (I have air knives here at work that do this), but missed that the air movement over the surface would also generate a lifting force as well.

A little more of a direct link to the info on the vortex tube.

First demonstration of Maxwell's demon was in 1928. The principal has been in commercial use since then.

For more info: (sorry guys don't know how to make it link.)
http://www.exair.com/vortextube/vt_page.htm?source =google&group=vortextube

How can you rotate anything without moving parts?

The gas moves into the chamber under pressure. The chamber is shaped to send the gas into a whirling vortex. Then the hot molecules go one way and the cold ones go the other. But I think it takes very high pressures to produce the required speeds.?

this place sells them and they even explain the theory with neat diagrams. apparently, you don't need extremely high pressures, only 80-100 PSI, to produce temps of -50 deg F! a shop air compressor could easily supply that.

i guess that the attractive thing about the vortex tube is that it's extremely simple (ie. inexpensive) in it's construction with corresponding low-to-no maintenance.

My company cools electronics enclosures in hazardous locations (oil refineries, etc.) with vortex cooling. These coolers are commercially available and work great, but they consume a lot of compressed air. They don't have any moving parts either. I used to conduct field trials in Sardinia, Texas and Louisiana a few years back and we always used to keep bottled water frosty cold using the cooler in our controls cabinet. Great when you've been standing around on the tarmac all day with an external temperature in the high 90's.

There are already commercial "vortex tubes" available. they are apparently used often in manufacturing and other industrial applications. Here are a couple of links:

DISCLAIMER: These are COMMERCIAL links, I have no affiliation with these companies.
AIRTX
EXAIR - This one has a nice animated illustration of how these things work.

One of my questions is why have not these been adapted for use in automobile A/C - despite the fact that they are inefficient, it seems, the clean nature, and the fact that they would need little maintenane. Virtually every car I have ever owned has needed AC. Even if it only worked when moving, it would be useful. But it seems like they could be used to also cool the engine itself too so less toxic chemicals like anti-freeze would be needed.

-MS2k

Good analogy, except that Maxwell's Demon really does exist.

Real Men (TM) use these
of course you also need this
to run it and this to keep your system from shorting out!
(Make Tim PROUD of you! grunt grunt grunt...) };-)