Jeff Liebermann wrote:
On Sat, 03 Jan 2009 18:53:59 -0800, Jeff Liebermann
wrote:

Thermal Conductivity Viscosity
W/mK cSt @20c
Water 0.6 0.9
AF (glycol) 0.24 2.0
Water+AF 0.8(?) 1.5 50%/50%
Silicon Oil 0.1 varies radically
Mineral Oil 0.138 34.5
Fluorinert FC-77 0.063 0.75

Air 0.025
Copper 370.
Diamond 1000.

Ok, I see why. Water has 1/5th of the thermal conductivity of mineral
oil. 50/50 water and antifreeze won't work. That raises the boiling
point but ruins the thermal conductivity. Pure ethylene glycol looks
tolerable. Other than the health and ecology issues, any reason that
100% antifreeze won't work?

Sorry, I goofed. Vicodin etc. It should be the higher the W/mK, the
better the thermal conductivity.

So why is Fluorinert favored for cooling when it has such a lousy
thermal conductivity?
http://multimedia.3m.com/mws/mediawebserver?66666UuZjcFSLXTtnxTE5X46EVuQEcuZgVs 6EVs6E666666--
Since it's usually circulated with a pump and involves direct
immersion, is it because of it's low viscosity and superior electrical
characteristics?

It would also appear that water has 5 times the thermal conductivity
than mineral oil. So, why use mineral oil?


It doesn't turn to steam or otherwise evaporate.

Dave WD9BDZ