Here is a way to keep cool.  You could even sleep in one while camping, or
with long hose, you could enjoy the outdoors.

http://www.coolshirt.net/racing-all.html

  Don Hanson

On Thu, Jun 10, 2010 at 7:31 AM, Dave Mcneely <mcneely4@cox.net> wrote:

> ---- David Beierl <dbeierl@ATTGLOBAL.NET> wrote:
>  Which always leads me to wonder
> > what happened to the ROVAC
> > system.
> > <
> http://books.google.com/books?id=WwEAAAAAMBAJ&pg=PA84&lpg=PA84&dq=rovac+air+conditioner&source=bl&ots=VvTiK97nzA&sig=2MCLGpTq0lnWCCKsLv6nDvNvFmQ&hl=en&ei=DX0QTOeRCcP38AaVwOH-BQ&sa=X&oi=book_result&ct=result&resnum=7&ved=0CDUQ6AEwBg#v=onepage&q=rovac%20air%20conditioner&f=true
> >
>
> Well, David -- that article is 35 years old.  I followed the description in
> detail.  I keep thinking something like, "No free lunch."  Does air really
> have that much thermal capacity to provide that much cooling effect from
> compression and expansion?  Especially as the article describes the system
> as recouping much of the energy used for compression.  I wonder.  Of course,
> I haven't done any calculations, and would have to go back to some old books
> to be able to do so, after so many years.
>
> On a much simpler (and only marginally effective) note, back in the day,
> there were swamp coolers to hang on cars.  A metal cylinder with some sort
> of evaporative surface inside and a grill to catch air, with a snorkel to
> direct air into the passenger space, was hung on the car window.  No
> meaningful energy expenditure occurred (some nominal gas mileage effect from
> the drag), and relatively cool air blew onto the car's occupants.  My
> brother put in ice once, which set off my Dad's fiscal alert system, and
> resulted in a lecture about economy (said brother had bought the ice,
> probably a dime's worth at the roadside service stop).
>
> Ain't life odd?
>
> David McNeely
>