What Is Phase Change Cooling? and how does it work?

[member_leaving 0]

I first came across phase change cooling when I bought the Zalman CNPS9500 heat sink. Basically the base of it (which is pure copper) is connected to what is being called "Heat Pipes (also pure copper)" and then a bunch of little copper "Fins" are attached to that. The fan sits perpendicular not parallel to the base which is why I bought it. I was curious as to how it could cool better than some water cooling that I decided to do a little research. I found out that the "Pipes" are actually hollow and they are filled with some type of liquid that at room temperature is almost a gas. While this is in liquid form it sits right at the base of the heat sink, on top of the CPU and main heat source. As the CPU heats up, the liquid heats up and goes through a "Phase Change" hence the name Phase Change cooling. The matter is now in a gas form and has taken the heat energy away from the heat source and "floated" out to where the fan and fins are, the fan and fins cool the pipes, thus cooling the gas. The gas then goes through another phase change and turns back into a liquid. The liquid is now heavy again and so it sinks back down to the heat source. The cycle repeats over and over, so the heat sink doesn?t use any pumps or condensers because it is all contained in the pipes. As effective as water cooling, yet not as bulky and uses less power to operate, plus you don?t have to worry about leaks. If I am wrong about anything please let me know so that I can have a better understanding.

[uiop 0]

Intresting. I've never heard of something like this before. It sounds like a new gadget for me to buy!How much was the heatsink?

[member_leaving 0]

Intresting. I've never heard of something like this before. It sounds like a new gadget for me to buy!
How much was the heatsink?

The heatsink I bought was about $60 at newegg. There are also a lot of other products out that are using this new phase change cooling technology, like the new Asus A8N32-SLI deluxe Motherboarduses heatpipes to cool the northbridge and take the heat into the path of natural airflow. I know that many of the Zalman heatsinks and other graphics coolers use heatpipes. There are a number of products that use heatpipes and I would recommend any of them to you. many can be found on Newegg. I also know that many of the sythe brand heatsinks are using heatpipes as well.

[uiop 0]

Do you have any idea what the liquid/gas substance is?

[member_leaving 0]

I dont know what exactly the substance is but I can find out. I sent a request to Zalman asking that very question. I beleive I will get an answer unless they use a special one and dont want to give away information. I found a great article while I was searching for the answer to your question, on SystemCooling.com.

"The magic of a phase change system comes from the substance used to transfer the heat from one place to another, namely the refrigerant. This magic is due to a property called latent heat of vaporization. This technical-sounding term can be reduced to a very simple concept - a good refrigerant absorbs a huge amount of heat as it changes from a liquid to a gas (or changes phase). Think of it in terms of an aerosol can. Have you ever been using a spray can and felt the can grow cold as it was sprayed? That's a small example of a refrigerant in action. As the can is used, the pressure inside drops, the liquid propellant evaporates, absorbing heat, thus the can grows cold.
Chemists have long known that one of the best refrigerants is a CFC (chlorofluorocarbon) based substance commonly known as freon. However, what these chemists understood only later, and to the detriment of everyone, is that CFC based refrigerants are absolutely horrible for the environment, particularly the ozone layer of Earth's atmosphere. They went back to the drawing board and have, over the last 15-20 years, worked on developing non-CFC refrigerants that work as well as good old freon. An example of this newer breed of refrigerant is R134a, which is used in many refrigeration and air conditioning applications. In the case of the Vapochill LS, its system is designed to use either R404a or R507 refrigerant, which are variations on the same theme (R404a is actually a blend of several refrigerants, including R134a)."

I will post another reply wiht the exact quotes of the Zalman Rep when I get a reply.

[gameratheart 0]

Using a gas to help power a fan, then turning it back into a liquid, heating the liquid, and continuing the process over and over again?It sounds like a cool idea (pardon the pun), and I can see why it would be so effective and expensive!The gas you explained about sounds very much like nitrogen or hydrogen... I would say nitrogen because it turns into a gas on contact with the air, and also it's environmentally friendly.

Edited May 18, 2006 by NDPA (see edit history)

[member_leaving 0]

Using a gas to help power a fan, then turning it back into a liquid, heating the liquid, and continuing the process over and over again?
It sounds like a cool idea (pardon the pun), and I can see why it would be so effective and expensive!

The gas you explained about sounds very much like nitrogen or hydrogen... I would say nitrogen because it turns into a gas on contact with the air, and also it's environmentally friendly.

The gas doesnt actually power the fan or make contact with the air. all the gas is contained in the pipes, and it cycles through it. the gas never escapes otherwise you would have to refill it every time. It is the same idea that is used in air-conditionars and refridgerators. the fan is only used to cool one end of the pipe that is then used to cool the gas back into a liquid. the processor is the condensor that turns the liquid into a gas.

[member_leaving 0]

This is the lame reply I got from the Zalman's rep;

"Dear Mr. Thomas,
We would like to greatly thank you for your interest in ZALMAN.

However, we cannot provide people with information regarding the exact ingredient/substance for the coolant inside ZALMAN heatpipes.



We hope you understand why we cannot do so J

Best Regards,

Support/ZALMAN"

So basically I didnt get any more information than I already had

Notice from BuffaloHELP:

Always use QUOTE bbcode for anything copied and pasted.

[uiop 0]

This is the lame reply I got from the Zalman's rep;"Dear Mr. Thomas,

We would like to greatly thank you for your interest in ZALMAN.

However, we cannot provide people with information regarding the exact ingredient/substance for the coolant inside ZALMAN heatpipes.



We hope you understand why we cannot do so J

Best Regards,

Support/ZALMAN"

So basically I didnt get any more information than I already had

Why do that want to hide it? I'm sure it's patented and a trade secret.

I hate lame customer support resonses .

[Uentil 0]

cOOl, i just thought the name "What Is Phase Change Cooling?" sounded interesting and then i read it and im like "Wow". Well explained and thats really cool how it works... Good job!

[unicornrose 0]

The chemical is probably a trade secret. If they tell you waht it is then they may have other people trying to make it too. Also if the pantents are not completely gone through that may be why too. Also I think that the chemical is probably a liquid at room temperature. It honestly should be because of pressure. It could be though but I am thinking its liquid at room temperature because when the fan cools it to liquid form its using room temperature air. This is pretty fascinating though.

[Goosestaf 0]

so does this offer dramaticly better cooling for the CPU?mine at the moment (due to being summer) tends to hit higher temps of 50-59 degrees pretty effortlessly.Would anyone who's ucrrently got one of these new fangled heatsinks tell me if it would be worth investing in one?i'm really not keen on upgrading to liquid cooling. . . . because i simply don't trust myself to do a good job lol.

[Uentil 0]

Dude, thats hella awsome how it works, i bet the person that invent it is richer than hell....

[iGuest 3]

Replying to member_leavingActually the potential for leaks is still there. TA similar method of cooling already exists in compressor refrigerant systems. Kind of funny why customer service is secretive. Perhaps they don't want you to know it may be a CFC.-reply by James

[jopak134 0]

yes it's really cool! how a basic thing can turn out to be so great. if they can just apply it to everything then where all set.