Phase Cooling example

pyr0 · 06-14-2009, 11:51 PM

Quote: Originally Posted by jellymonster

I feel that there should be a cooling section under MP3Car technical.
I am struggling at the moment to keep my CPU cool during summer and have resorted to underclocking :S
Also I would like to see if anyone has attempted water cooling in the car

Thanks

if it is that bad i would recommend phase cooling, otherwise refered to as thermal electric cooling

link here
http://www.jaycar.com.au/productView...c&form=KEYWORD

while at 68watts if may be a problem for 12-12 PSUs however, at up to 68 degreesC difference to ambient it could keep your CPU at (45C Summer Temp + Car Boot = 60-100C) 20-40 degrees which is nice, in winter i would change it back though as condensation could be a problem

as for forum suggestions, the Linux Forum could use some well writen FAQs, i agree with a cooling forum as well as a How To Forum, where people could go for all How To's, instead of trying to find them in the other topic forums

just for interests sake jelly here is my PC and cooling set up

120mm and 2x80mm for intake, custom 'GRILL' side panel

2x60mm High Speed Exhaust Fans

malcom2073 · 06-22-2009, 05:01 PM

Peltier != phase cooling. Thermoelectric coolers are not very efficient, on the order of 10-15%, however phase change (commonly known as refrigeration) is one of the best known ways to cool a computer. Example link: http://www.crazypc.com/products/phasechange.html

chris350 · 06-22-2009, 05:29 PM

ugh..i wasted my money on those thermoelectric crapola's...the use to much power for what they cool...its not worth it. fan cooling or water cooling..if you are daring ...is still the best way..especially for carpc's

malcom2073 · 06-22-2009, 05:43 PM

Ah yeah that's unfortunate.

Don't get me wrong, I don't suggest phase change cooling for a car, there's almost no reason for it except in extreme situations. Fan cooling, or even water cooling will be plenty. The key is airflow, if you are overheating chances are you don't have enough airflow.

rogerdugans · 06-22-2009, 05:57 PM

Phase change is actually not the same as a TEC, or Peltier.
Thermoelectric coolers CAN do a great job but they actually increase the heat load of the SYSTEM. The chip being cooled will be cooler, but the exhaust air will be considerably warmer. A LOT warmer.

Phase Change is the process of compressing a gas to a liquid state and then suddenly releasing it to expand- the sudden expansion (the Phase Change) provides cooling. This is how air conditioners and refrigerators work.

In computing, Phase Change is most commonly put into use as Direct Die Phase Change:
the chamber where the expansion (and cooling) occurs is mounted on the cpu, just like a heat sink. ALL of the refrigerant power is put to use to cool JUST the cpu.
This is VERY effective and can easily result in subzero temperatures under full load.

But in a car computer.... yeah, not so effective. A compressor will either rob engine power (belt driven like car ac) or electric load on the battery- and it will generate a LOT of heat.

Air cooling is definitely the simplest and can USUALLY be done successfully with planning and care, and maybe a few low noise fans.

Water cooling is a bit more complex, but if you are struggling with air cooling, and trying to figure out how to duct intake and exhaust air to keep the system stable, it may not be much more complex.
*Modern pumps add little heat to the system and run on 12v (computer psu.)
*1/2" Inside Diameter tubing is most common in High Performance water cooling, but 3/8" or even 1/4" ID can do a decent job in a system that is not highly overclocked.
And small tubing is easy to route.

A few points though:
Water cooling still depends on Ambient Air to cool the radiator down- it just makes it easy to relocate WHERE you send that warmth.
Water cooling will NOT cool everything in a system like Air Cooling does: only the chips with water blocks will be cooled. (Other components will benefit from the LACK of all that extra heat nearby.)
Some airflow is still required to cool motherboard components such as chipsets, voltage regulators and memory.

jeffeulogy · 06-23-2009, 09:33 PM

just a thought but one upside to using a pelt could be that they're not very sensitive about voltage fluctuations. you could connect it directly to switched power and engine cranks, transient spikes, etc won't kill it.

still probably not worth it considering if you can't air cool a stock a processor cooling the pelts hot side is definately not going to happen.

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