What phase change cooling?

airbornflght

Is that just a fancy word for sticking a refirgerator cooling systemin a computer. cause i have thought about it. but the heat exchanger is WAY too big. other than that the freon gets around -?? after being compressed.

Armo

ye, phase change just describes the method of compressing a gas to a liquid, then it uses a vaporizor, like a release nozzel, and it decompresses to a gas really fast, over the cpu, this phase change makes it REALLY cold. they make phase change coolers for PC's that run ~$600

you have to insulate the processor and the mobo to do this or the condensation will blow ur machine

MAGIC

imo a good watercooling system costs less than half the tag of a phase system, and thats all you need.

lemonlime

Phasechange is probably one of the most efficient ways of getting sub zero CPU temperatuers. They are bulky, but some of the 'kit' versions, like the nventiv mach II, and the vapochill LS, are quite compact, and sit neatly underneath your case. Peltiers (or TECs) can get you below zero as well, but not with the same efficieny of a vapo or mach II. Its certainly not for the faint of heart though, only the hardest-core overclockers will be interested in this form of cooling. Water and high end air cooling are great, but they'll never get you sub-ambient temperatures.

airbornflght

i know that. and if i was to go phase i would retrofit a rerigerator's system into a computer, cause thats al the commercial ones are...same compressor, just a more compact heat exchanger.

all i would need would be the proc block and other stuff.

and ive looked at peltiers for other reasons before but couldnt find any thing over a few watts, which is not enough, considering that you would need one rated for more watts than the proc puts out as heat.

lemonlime

airbornflght wrote:

i know that. and if i was to go phase i would retrofit a rerigerator's system into a computer, cause thats al the commercial ones are...same compressor, just a more compact heat exchanger.

all i would need would be the proc block and other stuff.

and ive looked at peltiers for other reasons before but couldnt find any thing over a few watts, which is not enough, considering that you would need one rated for more watts than the proc puts out as heat.

Hey, sounds like an awesome weekend project . There have been quite a few people over at xtremesystems who have build some pretty crazy custom phase-change units.

There are quite a few 'pc grade' peltiers, in the 80-227 watt range, but they need beefy, dedicated +12V psus. I believe the 227watt models usually draw upwards of 25A. Cooling the hot side of a 227watt pelt is tough too, think you'd need watercooling to get sub zero temps.

edcentric

Phase change cooling is called that because it is the energy absorbed in the changing of phase, from liquid to gas, that allows you to remove heat. The key isn't delivering a cold fluid to the item that you cooling, it is delivering a fluid under conditions that it will boil. The reasons that you do this are simple thermodynamics. The changing of phase requires (absorbs) a lot more energy than simply heating a fluid.
There are other methods, but this is the most efficent for serious cooling.
The next best option is to 'water cool, but don't use water. Use alcohol or some other low freezing liquid and chill it with a frig instead of just air cooling.

The best demo that I ever saw was some guys at HP took an inkjst print head from a plotter. It had 300-400 nozzels and it was about 1cm square. They placed it above a RISC workstation CPU that had no heat spreader or heatsink on it. They then programed the individual print heads to fire just enough to keep each portion of hte CPU cool. They delivered just enough water to boil on contact, no liquid was left. They used water and the peak CPU temp was 102C. No fans, no pumps, no compressors.

Nosferatu

102C?!!?

airbornflght

yeh...ill stick with my hs and fan with 60*C