What kind of temperature drops can I expect with water/air cooling?

TheCrazySquirell

Honorable
Mar 5, 2012
29
0
10,530
Hi!

I have decided to start a small project to cool a system (specs not confirmed yet) by immersing it in mineral oil in a fish tank and want to know:

What kind of temperature reduction should I aim for?
What kind of oil should I use?
and probably what has baffled me most, are there any small pumps I could use to direct flow at certain passively cooled components like the gpu and ram apart from two fairly large aquarium filter/pumps without the filter part on them to provide the general flow of the oil.

I hope to create some form of a log on what I am doing, so if you people are interested in seeing the results I would me more than happy to share them :D

Thanks,

Artur.

 

rubix_1011

Contributing Writer
Moderator
The mineral oil thing was a big thing about 5 years ago when all those people decided to try it. It's a very poor heat conductor and it traps large amounts of heat without dispersing it. It takes much longer to absorb as much heat as water, and likewise, takes a lot longer to disperse. You also have to resort to soap and water cleanup and a very long dry time if you wish to remove parts from the oil...and in most instances, you can't get it all as PCB is very porous.

To add- mineral oil degrades thermal paste, rubber and some plastics.
 

Lutfij

Titan
Moderator
didn't know that last line of info... :/ might as well take some liquid metal and apply it to anything alu in your case as you're going to kill it anyway with mineral oil.

* rubix - five years ago, why, i remember a guy buried his machine 6 feet under to keep it cool.
 

rubix_1011

Contributing Writer
Moderator
There are people who have done this, but every single one that I have read have said it's a horrendous P.I.T.A. to do and keep maintained. You also run into the likelihood that you'll never be able to resell your components. I'd suggest a quick lookup of the thermal conductivity and specific heat of oil vs. water.

Specific Heat (kJ/kg.K) and (Btu/lb.oF)

Specific heat is the amount of heat required to change temperature of one kilogram of a substance by one degree. Specific heat may be measured in kJ/kg K or Btu/lboF.

Water, fresh [4.19]..................[1]
Oil, mineral [1.67]..................[0.4]

Thermal Conductivity

Thermal conductivity is the quantity of heat transmitted through a unit thickness in a direction normal to a surface of unit area, due to a unit temperature gradient under steady state conditions.

Substance ........ [Temperature ranges in Celsius- 25 C/125 C/225 C]

Aluminum [250].....[255].....[250]
Copper [401].....[400].....[398]
Gold [310].....[312].....[310]
Water [0.58] [obviously steam past 100C]
Oil, machine lubricating SAE 50 [0.15]

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html
http://www.engineeringtoolbox.com/specific-heat-fluids-d_151.html