Thermosyphons and similar craziness

[deathBOB]

Hmmm.... Moderate overclock with Silence for $50? Sounds like a deal to me!

 

[WarriorII]

I think this system rocks!

Macklin01 -

if ya look around at some / most of the A64 set ups - they reall don't have that big of an overclock at all.

- I mean really, it's not like the old days where 500+ mhz got squeezed out of a cpu.
now we're lucky to see 200mhz, maybe a bit more.

Is there someone running an A64 over 1.7-ish volts?
(i'm sure there is but I havent seen it)

I'm not tryin to bash anyone, I really like this concept.

sheez, 36cfm.... I'll trade my 108cfm/120mm for it in a heart beat.

For those not familiar with it, this operates on the same principle as an air conditioner.

I wonder what "fluid" they have inside the system? R12 is being phased out, I wonder if it's alone 134a or a house hold type refridgerant?

 

[John G]

I wonder if you guys missed this article?

http://www.overclockers.com/tips1211/

Because it's more or less the same concept. Hot water moves up, replaced by cooler water, creating movement in the loop. I just find it strange that no one discussed that informative article.

Also, how does the calm-sv radiator work? Looks odd to me, both incoming and outgoing lines are on the same side (and in close proximity to each other). I wonder if there's some water routing inside that seperates the incoming and outgoing lines?

*edit:
ok, i guess ls7corvete's writeup wasnt all that informative, but shortly after reading it a week or two ago i looked up posts on pumpless watercooling. Going by memory, i just remembered/assumed the article as having alot more detailed info. Here's a link that i probably stumbled upon on the pumpless threads.

http://www.plees.f2s.com/ec/pas-cool/pas-cool.htm

Actually, it's probably a very different system. It makes no mention of boiling the liquid, which is the main cooling function of the "thermosyphon". It looks like more just a standard water cooling system minus a pump and plus a TEC.

I was pretty interested reading that article as well, though.

 

[John G]

For those not familiar with it, this operates on the same principle as an air conditioner.

I wonder what "fluid" they have inside the system? R12 is being phased out, I wonder if it's alone 134a or a house hold type refridgerant?

If it were one of those typical type refrigerents, it would have to be a pressurized system instead of one under vacuum.

This one is probably something closer to water from a properties standpoint.

It's similar to an standard air conditioner in that it uses phase change to cool with an evaporator and a condenser... But, it is also very different because it doesn't have a compressor or an expansion valve and it's a passive system instead of one that you input work. An air conditioner is like the refridgeration systems that can force the cooling to occur almost regardless of the temperatures. This system can only start cooling after the CPU is hotter than the boiling temperature and the ambient temp at the radiator is lower than the boiling temperature. Kind of like a passive temperature regulator rather than something that forces cooling.

 

[skou]

II wonder what "fluid" they have inside the system? R12 is being phased out, I wonder if it's alone 134a or a house hold type refridgerant?

If you guys follow the link in the original front page story, these questions are answered.

http://www.hpl.hp.com/research/papers/2002/thermosyphon.pdf (#2)

It was water, and another un-mentioned fluid, in 2 different tests. Water came out the best.

steve

 

[JTanczos]

Seems like an interesting design. Although with such a small fan "Quiet" might be a relative term. The high pitched whine of those fans can be more annoying then the whoosh of 120mm fans at full blast.

JT

 

[Voodoo Rufus]

It may be neat, it may be marketable, but you still can't beat the laws of thermodynamics with regard to surface area and diminishing returns of increasing it.

The C/W numbers are noteworthy, but as mentioned before, nothing overwhelming.

I could see different thermosyphons being marketed with different wattage ratings for CPUs, depending on the type so that you operate in the most efficient range for the system.

 

[Skeen]

Macklin01 -

if ya look around at some / most of the A64 set ups - they reall don't have that big of an overclock at all.

- I mean really, it's not like the old days where 500+ mhz got squeezed out of a cpu.
now we're lucky to see 200mhz, maybe a bit more.

You should look at this thread: http://www.ocforums.com/showthread.php?t=319185

Lots of people get over a 200MHz overclock. I'd be really freakin' ****ed if that's all I got out of a chip. Personally, I can run with a bit more than a 900MHz oc.

 

[WarriorII]

I like being proven wrong. 1.85v on H20. It lets me know that people are paying attention.

"Most" of the voltages are below 1.7v.

Which is a lot easier to cool than 1.7v+ is what I was getting at.

Yeah, I'd be pess't too if all I got was 200mhz o/c.

the multiplier's aren't 12+, but the FSB's are really up there.

/peace

 

[PoX Freak]

OK, heres my thoughts on this type of cooling...
First, in order for this to work, a vacuum must be introduced into the system. The vacuum must remain constant in order for gaseous convection to take place. Once that vacuum has been removed, the boiling point rises and cooling pretty much decreases exponentially across the entire heat range.
I e-mailed Joe on this, giving my comments and asking questions since I also have been thinking about and conversing over this type of system. I have a few engineer friends of mine that answer some of my most unintelligent questions, but pretty much put up with it because they want to see something new or interesting (i guess the HVAC field is getting a little boring for them).
Secondly, any fluid used in the system must be at least non-toxic, if not biodegradeable since we live in a throw-away world... We wouldn't want this stuff coming back to haunt our children, would we? That takes any type of refrigerant out of the system. No r12 (banned from use anyway since 1996), no r134, nada. The only coolant allowed at this time would be deionized distilled water.
I am a facilities manager, so i work with HVAC alot (especially the summer months). I could see such a system going mainstream, as long as all factors are figured for (price/performance, ease-of-use, "coolness" factor, lifespan, etc.

 

[John G]

The pressure doesn't have to remain exactly constant, just close enough that you can maintain an equilibrium. The tests showing the lack of change in temperature from idle to even mildly overclocked at full output show that it's quite achievable. In the end it just comes down to being able to remove heat from the system as fast as you're putting it in.

By the time you boil and fail to condense enough of the water/steam to significantly pressurize the system, you are in an overload condition. Which is a condition from which it will recover if you reduce the heat input enough.

 

[RoadWarrior]

Heh, I told him that would happen a year or so ago when he was testing the first heatpipes. The temp going up rapidly until you hit the boiling point, then it would about stick there until you reached the limit of recondensing it at the other end. With more liquid, as in these, you get a wider performance range, but the basics are the same.

Think he probably ignored my mail as crackpot since I disagreed with his testing methods, which were the same ones he was using for regular sinks. Either that or it got lost in his spam hole.

Road Warrior

 

[Aaron Burton]

pox freak-
I'm not sure where you're getting your information from, but it's not entirely accurate. As of right now, all refrigerants are legal in the United States and available for both virgin use and recycled use, with the exception of CFCs, which violate both the Montreal and Kyoto Protocols. Distilled water is an option, but there are still many other options available, including R134a. The United States, Canada, European Union and less developed countries are all on unique timelines in terms of phase-out of these refrigerants, with the EU's being the most accellerated. HCFC's pose far less and HFC's pose no ozone-depleting threat, though they are all greenhouse gasses. In addition, CO2 under high pressure can also be used as a refrigerant, though it's a little more difficult. Coke has actually started using CO2 in their vending machines.

When you get down to it, all solutions have their pros and cons. Keep in mind that the electricity that you would use to maintain a motor in a watercooled PC system would use fossil fuels, and also release greenhouse gasses. The trick is to find the best solution possible for a given problem.

 

[JaY_III]

Keep in mind that the electricity that you would use to maintain a motor in a watercooled PC system would use fossil fuels, and also release greenhouse gasses. The trick is to find the best solution possible for a given problem.

Hydro electic for me.
Nothing but hydro
Burning feul for power, gross

 

[Aaron Burton]

Just because you're using a renewable energy source doesn't mean there isn't any externalization. The perfect example of this is the three gorges dam. The silt problem is extreme. Not to mention that there aren't a ton of places to utilize hydroelectric generation, and any kind of energy gathering method you use is going to require maintainance, which also eats up resources and energy costs. There really isn't a pure solution to the problem. There are definite bad paths, but there aren't concrete "best" paths.

 

[BeerHunter]

I don't see what the big deal is. Looks identical to a heatpipe heatsinks out there like XP90 but with a longer "pipe" up to a larger "sink". Have no idea how he got a patent on this extension/enlargment idea. Unless I'm just missing something???

 

[John G]

I don't see what the big deal is. Looks identical to a heatpipe heatsinks out there like XP90 but with a longer "pipe" up to a larger "sink". Have no idea how he got a patent on this extension/enlargment idea. Unless I'm just missing something???

Kinda, yeah... I don't think he said they have a patent on it. But, did mention something about filing for them.

That patent stuff can be some tricky business. They can try to patent an exact implementation so that people can't copy it exactly. Or, maybe the use of a specific fluid or something. It probably wouldn't be hard to get some patents on it or parts of it. The harder part would be if other people start making them or something similar, fighting things out in court.

For example, I remember Carver got some patents a while back on what basically amounted to parts of a small powered subwoofer. They were commercially producing really small sealed home theater subwoofers before most of the industry, but there was absolutely nothing at all in the package that hadn't already been done before years ago. So, they had patents on all these little things like high output plate amps, EQ circuits that were basically just a linkwitz transform, small boxes, low Q-high excursion subs, etc. And, then when other people in the industry started making typical subs that were just an expected evolution of the market, Carver started suing them for stealing their ideas. It was ridiculous. If I remember right, much of the industry fought back, showed the court how the things Carver patented had been standard stuff for years, and got the patents struck down. But, it took years and lots of money.

Seems like the best they could hope for with this "thermosyphon" is to maybe keep people from exactly copying it, but they may not even be able to do that. Even so, if they just get to the market quickly with a good product for a reasonable amount of money and advertise effectively they can still probably make quite a bit of money before they have any real competition.

 

[PoX Freak]

They'd be great with a way to adjust vacuum, so you could set the thing up for a specific use or temp. just like tuning a machII for the best temps. I'm not saying pull a vacuum to the point where the tubes collapse (would be funny to see), but adjust it in small increments, say .01-05 mmHg at a time.

 

[I.M.O.G.]

I don't see what the big deal is. Looks identical to a heatpipe heatsinks out there like XP90 but with a longer "pipe" up to a larger "sink". Have no idea how he got a patent on this extension/enlargment idea. Unless I'm just missing something???

Look at the latest article, theres an obvious limitation of heatpipes, and you can see where thermosyphons may surpass them. There's probably something your missing.

 

[yanz]

JPEG is lossy and suitable for natural photography not for screenshots! Joe, please save your screenshots as PNG image files and *not* JPEG.

I enjoy the articles, though...