Well there we are...some actual definitave numbers from a 'scientist' or
an engineer.
  For those of you who are not comfortable with 'anecdotal' evidence,
gathered in an informal manner, coming  from laymen..
  14%  (+/-) would be appx. how much cooler my power-sports stuff seems to
operate on Water and Redline Water wetter than it does on anti-freeze mix.
   Whenever I am faced with a problem or a situation where I am 'skating on
thin ice' with the performance parameters of some system, I simply look
around at others using similar systems, ask em how they make it work right,
and then  emulate what's working successfully for them...I don't need to
know why, most of the time, or have actual test numbers before I accept and
adopt a working solution...I just copy and move on to the next problematic
thing...
 I'm very happy to have the Vanagon list so i don't have to solve all these
'long known' issues again for myself...I just ask or check the archives and
move on..
  Don Hanson
On Sat, Dec 12, 2009 at 12:20 PM, Jim Arnott <jrasite@eoni.com> wrote:

> Short answer: yes. Water transfer heat better than glycol.
>
> Longer answer: When I worked in aerospace about a century ago, one of
> my first assignments was process control for the heat treat area.  We
> solution heat treated a bunch of aluminum.  (Solution heat treat: <
> http://www.azom.com/Details.asp?ArticleID=2540
> > This was done to soften the material for forming.  To reduce
> residual stress, we used a quenchant of 20% polyalkalene glycol.  This
> provided a slower quench than water.  Quenching in water would have
> resulted in much more residual stress and distortion. Slower quench =
> slower heat transfer.
>
> Numbers here:
> http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html
>
> http://www.engineeringtoolbox.com/overall-heat-transfer-coefficients-d_284.html
>
> Water is about 14% more efficient at 220 deg F.
>
> Jim
>