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Liquid Cooling and Cooligy

submerged cooling

nitropowered:
you can indeed cool by submerging the motherboard in a non-electrically-conductive medium. after reading a bit ab out it, and friend and i created a fish-tank computer by filling an aquarium with mineral oil and fitting the motherboard into it (except the power supply!). it is a totally passively cooled system though, based on the large volume of oil to transmitt the heat to and out of. not practical for serious overclocking.

the ideal coolant for liquid-based systems would deffinetly not be water. it has a very high specific heat, so it can absorb a lot of heat energy, but it doesnt have the best heat transfer properties. plus there are the obvious problems associated with leaks.

the issue in liquid cooled system break-downs is not the liquid on the components (since the coolant likely isnt water), just the fact that the computer would no longer be cooled at all (and thus not useable) if the liquid leaked out or the pump broke, etc... it would take vey careful and clever engineering to make an efficent and reliable liquid cooling system for a laptop.

my $0.02
cheers,
scratch
 
Originally posted by scratchh
it would take vey careful and clever engineering to make an efficent and reliable liquid cooling system for a laptop.

my $0.02
cheers,
scratch
Click to expand...

...and it's been done and is currently used in IBM Thinkpads (gotta love their research budget!) since the A20, which was in '99. They use liquid cooling in a sealed hinge. (and they do use water)

See here:
http://www.research.ibm.com/thinkresearch/pages/2001/20010808_cooling.shtml
 
You can effectivley cool a comuter system (not inludin moving parts, HDD, CD, etc...) bu submerging the entire system in mineral oil. No fans, convection powers the system.

While this is very unlikley, to have computers submerged in oil, such a fluid could be usedina closed loop. Jus incase thepipes breake loose.
 
It's also interesting to see how opinions change over time. This is a link to an old tread, before the XserveG5 was announced:

"https://forums.macrumors.com/showthread.php?s=&threadid=42560&perpage=25&pagenumber=2"

It's worth a read.
 
Apple happens to hold a patent, for a small mobile cooling system. I forget most of the details. But one thing did stick out, a very interesting detail, witch was the coolant. If the coolant happened to escape it would not damage the computer processor, mother board, or any other components.

With a close circuit it's quite easy to detect a loss in pressure so you wouldn't have to worry about frying your computer.
 
Stupidity

Liquid cooled powerbooks are almost certainly a nono - There just isn't any point in doing it - in order for Liquid cooling to be any use you need a big radiator, and that with the pump and condenser are going to weigh a lot... It just isn't a suitable technology for laptops... As for desktops, I'm highly sceptical on that front, I think it's something that apple (a) don't need to do now the G5s run cooler and (b) wouldn't want to do unless really necessary, because saying that "your £3000 computer has liquid flowing inside it" is NOT going to inspire confidence in it's reliability. (Whether it's non-conductive fluid or not, your computer's still gonna fry when it springs a leak)

Bob
 
Re: Stupidity

Originally posted by beelesbob
Liquid cooled powerbooks are almost certainly a nono - There just isn't any point in doing it - in order for Liquid cooling to be any use you need a big radiator, and that with the pump and condenser are going to weigh a lot... It just isn't a suitable technology for laptops...
Click to expand...
Well apart from the fact that IBM has already proved it a suitable technology you're also wrong on the technicalities of it. Liquid cooling, as proposed by Cooligy, offers the ability to get a lot more heat out of the CPU then move it to an area where you can cool the system more effectively, it provides much greater flexibility in cooling system design than is currently possible and therefore ultimately better design.

If you've ever opened a powerbook you'd see they already have heat pipes all through them. There's no need for a condenser and in fact optimally you don't want to be boiling that water. The pump is smaller than the size of a regular fan and the infrastructure for removing the heat from the fluid is already there in the form of the heat sink it will just get moved to a better location.
Originally posted by beelesbob
As for desktops, I'm highly sceptical on that front, I think it's something that apple (a) don't need to do now the G5s run cooler and (b) wouldn't want to do unless really necessary, because saying that "your £3000 computer has liquid flowing inside it" is NOT going to inspire confidence in it's reliability. (Whether it's non-conductive fluid or not, your computer's still gonna fry when it springs a leak)
Click to expand...
I've seen servers with liquid cooling systems, in fact Virginia Tech's supercomputer is liquid cooled, as are most. You face just as much risk should a fan die as should your liquid cooling fail. Both are reliable barring extreme misfortune and there's no reason to expect it will spring a leak.
 
could someone explain this to me... why is there such a concern with heat for g5s? i was under the impression that a g5 pulls less watts at an equivalent clock than the g4.
 
simply amazing...

I'm amazed at the number of people making "statements" about this system - liability to break after a year, what the coolant is, etc - without bothering to read the article in question.

This is an etched silicon wafer with a water-based solution (not entirely water, there are other substances in the liquid but the exact make up is not revealed) flowing through the channels of the wafer 1mm away from the surface of the cpu.

It's a wafer on a wafer. If you broke the cooling system, in all likelihood you'd have cracked the cpu as well.

it doesn't use fans, b/c as the article says, the solution is pushed through the cooling chip by electric induction (electric current can induce motion in an ionic fluid). You wouldn't want the solution to be non-conducting, then it could not be efficiently moved by induction.

Now, of course, what this is is simply a better heat sink. In most cases (pun intended) you have a fan which blows air over the heat sink...in some designs a fan is not required within a particular system.

As for whether or not you would want the liquid to boil...in this system it is designed not to, but there are systems that have successfully used passive cooling and system inertia to recondense the cooling fluid and move it back over the cpu to be boiled again. It's not a bad idea (as some have phrased it), just difficult to execute properly. To overcome some of the problems, usually a substance with a low boiling point is used. The same concept is used to extract eletrical power from geothermal sites where the temperatures are insufficient to boil water.

Next time, perhaps we might try reading the article before making statements about how a tech will function and what would be a good or bad way to execute it!!
 
PS. What I can't wait for is a boiling-coolant system that turns a generator - turning the waste heat back into electricity to prolong battery life. They've already created laptop computers with B-C systems, all they need is a small version of a steam-turbine. It wouldn't take much room inside the case. Wonder what it would do for battery life??
 
Re: simply amazing...

Originally posted by cripdyke
it doesn't use fans
Click to expand...
There's one siting on the radiator. It still uses a standard air flow heat exchanger to cool the water.

Originally posted by cripdyke
As for whether or not you would want the liquid to boil...in this system it is designed not to, but there are systems that have successfully used passive cooling and system inertia to recondense the cooling fluid and move it back over the cpu to be boiled again. It's not a bad idea (as some have phrased it), just difficult to execute properly.
Click to expand...
The benefit in boiling a liquid is you can remove more heat. The disadvantage is it can kill your heat flux if you get past nucleate boiling. Since in this system you're really interested in getting as much heat out of that small area, the CPU, as possible you want a high heat flux. Ideally at peak operation it'd be nucleate boiling and other times convection but in reality I don't know of too many correlations that accurately predict it and that's a lot of control for the cooling system. There's better and easier things you could do than boil the liquid using Cooligy's design.
 
A nice picture of a heatpipe assembly

Originally posted by legion
...and it's been done and is currently used in IBM Thinkpads (gotta love their research budget!) since the A20, which was in '99. They use liquid cooling in a sealed hinge. (and they do use water)

See here:
http://www.research.ibm.com/thinkresearch/pages/2001/20010808_cooling.shtml
Click to expand...


Interesting, it sounds like they are using two heatpipes in series - one to carry the heat from the CPU to the bottom of the hinge, and a second in the top half to carry the heat away from the hinge into the top radiator.

Cooling and Cooligy were discussed in length recently at https://www.macrumors.com/pages/2004/02/20040223092546.shtml

A more conventional, and also effective, example of the use of liquid-filled heat pipes is in the Dell Latitude D600, a Pentium M (Centrino) system.

Here's a picture of the heat exchanger and fan:
thermal4.jpg


The plate #1 sits on top of the CPU, beside the fan. Two liquid-filled heatpipes conduct the heat from the plate to the rectangular radiator seen above the plate.

The fan sucks air from the bottom and side of the case, and blows it out louvers in the back of the case.

The radiator drops into position between the fan and the back of the case, so that the fan is blowing the air across the fins of the radiator.

It seems most laptops have been using heatpipes for some time, so there's really nothing special about the Dell except that the manual has a nice picture that shows how the heatsink, heatpipes and radiator are arranged.

Also note that the "plumbing" of a heatpipe is a self-contained single tube. No connections to leak, just one solid assembly.

A good description of how a heatpipe transfers heat can be found at http://www.thermacore.com/hpt_how.htm

heat-pipe-201.gif
 
I came into this thread not knowing a thing about liquid cooling, and there have been some really great posts to help me understand. Thanks!

This technology sounds great. As long as the liquid doesn't leak (obviously) and it's of sturdy construction, and dissipates more heat than fans, then I'm all for it.

Just one thing though: how will the liquid perform in the long-term? Like 5 years down the road, is there any chance that the liquid could evaporate or its state change? I'm assuming though, since this would be in a vacuum, that as long as the vacuum remains sealed that no evaporation would occur, but I'm certainly no expert on the subject. Anyone care to comment?
 
the natural thought is of g5 pb of course, but this technology would be extremely usefull in so many applications. every six months at work, we take the time to open up our macs clean out the fans, dusting, and making sure everything is running good. with liquid cooling wouldn't it be possible to make an enclosed system without having to pump "dirty" air through it, thereby keeping the components in a more sterile environment?
 
Originally posted by nitropowered
Yes, the "liquid" does not have to be water.

-- SNIP --

as I will be entering college and need a pb.
Click to expand...

umm... no it doesn't; the point of the liquid is to absorb heat and transfer it away from the processor. Any substance can do this all you need is:
1) a cool substance (as it absorbs more heat)
2) someway to cool the now hot substance

this process loops with a cool substance being warmed and transferring heat thus being cooled. Think of your heat sink now ... it is cool (has a high absorption rate) it gets hot (lowers the rate of absorption), the held heats is "blown away" by a fan making it cool (raising the absorption rate); so on an so fourth.

Water is effective because it easily transfers heat, but any other liquid could do this to varying degrees of success. Liquid nitrogen, for example, dissipates heat very well ... the problem there is the power requirements to keep such an inert gas in liquid form negate the gains from the cooling in the first place.


next fall take a thermo dynamics class, it will prove useful to you
 
I have asked this question several times on several different forums, and no one has answered me yet. Maybe you guys will help me out, please?

The question is, were pb g5's to be announced at the wwdc on june 28th, would they be available for purchase right then, or would one have to wait a period of time before online buying? I know I wouldnt receive it for a while, for sure, but could I buy it then?

Thanks very much guys.
 
Originally posted by a17inchFuture
I have asked this question several times on several different forums, and no one has answered me yet. Maybe you guys will help me out, please?

The question is, were pb g5's to be announced at the wwdc on june 28th, would they be available for purchase right then, or would one have to wait a period of time before online buying? I know I wouldnt receive it for a while, for sure, but could I buy it then?

Thanks very much guys.
Click to expand...

The reason no one has answered you is because no one here knows when the PB G5 will be announced or when it will be available. If we knew that then we wouldn't be here pining away for the date of release and speculating our tails off! :) :D
 
Read closely, that wasnt my question.

I wanted IF it WAS announced on teh 28th, is it typical that it would be available for purchase online (not necessarily to receive, as I know that it usually takes some time until they are released a la the mini) immediately, or would it take some time? I know the mini was buy-able almost immediately, so does anyone else know?
 
Originally posted by StarManta
Pure speculation... but a quad 2.5-GHz G5 would generate a lot of heat... seems like it would be a good system to put water cooling in.... ;-)

It may cost $5000 but hell, I'd be savin'.....
Click to expand...

A QUAD G5 is out of Apples leage, its not thier market and I dont think IBM would let it happen as the FULL power series takes care of that section not the cuttdown G5. $5000? try $10-15k the cost is not linear from a DP to a QUAD, the price difference is massive.
 
Liquid cooling is very reliable assuming you follow some very simple rules, the main problem is leaks at the fittings whether they just break or comeoff you have to use good fittings and seals/threads etc.. The other problem is the pump, eheim pumps rules here, having dual pump is better if your really concerned. Also the combination of TEC and liquid cooling is very effective (compared to VAPOR cooling, the only difference is you can cool multiple heat sources no a single heat source with VAPOR aka VAPACHILL/MACH2) but has very steep learning curve and risk with noobs.
 
Originally posted by army_guy
A QUAD G5 is out of Apples leage, its not thier market and I dont think IBM would let it happen as the FULL power series takes care of that section not the cuttdown G5. $5000? try $10-15k the cost is not linear from a DP to a QUAD, the price difference is massive.
Click to expand...

How do you figure? If the dual processor 1.8 costs $2,499, the dual 2.0 costs $2,999, you honestly expect the price to jump from $3K to $10-15K for a quad? No way. You could buy over THREE dual 2.0's for that price! They wouldn't sell hardly any. IF Apple did quads, I would be surprised if they priced it over $5,999.
 
Much bigger motherboard, higher power components and much more expeience in PCB design (longer traces, very dense multiple layer PCB's etc.) Lets just say its no small feat.
 
I realize it's not as simple as slapping on a couple extra processors, but from a marketing standpoint they'd be killing themselves with a pricetag that high. Okay, maybe $6,999... ;)
 
Originally posted by legion
...and it's been done and is currently used in IBM Thinkpads (gotta love their research budget!) since the A20, which was in '99. They use liquid cooling in a sealed hinge. (and they do use water)

See here:
http://www.research.ibm.com/thinkresearch/pages/2001/20010808_cooling.shtml
Click to expand...


That isnt liquid cooling, the term liquid cooling implies the use of a pump, radiator and heat block. That IBM thinkpad thing is basicaly a sort of heatpipe.
 
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