Prometia and Phase Change

I have been seeing a lot of people talk about this lately, and I was wondering...on a very basic level what these two cooling methods are, and why they are so effecient.

Prometia is just the name of the phase change system. Vapochill is an other one. http://www.chip-con.com/index.php?pageid=15 is the link to Chip-con who makes the Prometia and that page basically describes what is going on on order to cool the cpu.

usually when someone is talking about "phase change", they mean refrigeration,... like the thing that keeps your food cold. basically using a gas with a really low boiiling point, and through means of compressing to a liquid, boiling, and evaperating you end up with very cold results.

a prometia is just a trademark name for a premodded case/phase-change setup. like coca-cola or oreo cookie

Isn't the boiling point in a liquid simply when the atmospheric pressure equals the vapor pressure of the liquid? Like if you put water into a syringe and capped the end making the syringe watertight, then pulled the plunger out, increasing the pressure, the water would boil due to the pressure change with no heat. If this is truely the case than how does lowering the boiling point increase the heat transfer/coolness of the liquid/gas that is used in pahse-change cooling?

im not a expert on the subject but i believe it goes like this:
compress to liquid->boil off from heat at cpu core(heres where the low boiling point come in)->collecting of gas to start the process over

I guess that kind of makes sense, but I am still a little confused on how this thing works. Anybody out there know enough to give me some detail and insight into phase-change?

how a phase changes sytem works is you take like a 1/4 inch thick pipe that has a refrigerant runnign through it (freon, etc...) then you have a compressor that pumps this refrigerant through the pipes then the freon gets pumped into very very small tubes called capillary tubes (sometimes there is justy one cappilary tube btu some have two or three depends on size of compressor etc) once it gets into this cappilary tube the pressure is greatly increased but then at the end of capillary tube when it leaves the capillary tube the pressure is lowered a huge amount and this causes the refrigerant to boil, and the whole reason you want this refrigerant to boil is not to lower the temperature or anything like that it is simply because a boiling liquid contracts al9ot more heat than a liguid at its normal liguid state, then when you have this boiling freon it gets sent ot he evaporator which is where yuo have the cold air comign from (fans blowing air through the radiator type evarporatot) after it leaves the evaporator it then goes back to the compressor where the compressor raises the pressure back to normal again then pumps it back throught he process again

here is a website that should help you, just read over it

www.phase-change.com

http://www.wc101.com/guides/refridgeration/

another good guide

this one is a very good guide to just basic refrigeration this will explain how phase change works

http://www.refrigerationbasics.com/1024x768/rb1.htm

Thanks a lot guys, makes a lot more sense now.

well there is 4 main components in a refrigeration setup. This is the compressor->condensor->Metering Device->Evaporator-> in that order. The compressor compresses the gas so that it turns into a liquid state. The liquid gets cooled off by running through a condensor(radiator). Next is the metering device, this is either a very very small copper tube called a capillary or some kind of an expansion valve. This separates the high side from the low side. This basically does two things, raise the high side pressure so the gas will condense and limit the amount of refrigerant that is going into the evaporator. After the metering devise is the evaporator (thing that gets cold). The metering device will spray liquid into the evaporator and this is what makes the evaporator cold. Then after the liquid is boiled off it will be in a gas state and will go back to the compressor and the whole process repeats itself.

OK noone realy has said what the science is behind Phase-Change. It is all about something called latent heat. basically when a substance changes state it either emmits heat or absorbs it to change state. So when you compress your refregerant into a liquid it gives off heat. Then in your evaporator where it boils it has to take in the heat it gave off and hence absorbs heat from the surounding area.

Ahhhh, thanks Lynx, that is what I was looking for.

The whole point to "phase change" is evapouration. Hence the changing phases

Evapourating removes a lot more heat than simply conducting it through, which is why systems like prometia can often come extremely close to liquid nitrogen cooled systems.

In theory, if someone could make a controlled spray nozzle liquid nitrogen system the temps would be far lower than anyone else has seen, except that it would probably be almost impossible to do.