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Using Radiators to Cool CPUs
dan writes "Overclockers Australia have a review up of the CPU Radiator Zen, a new approach to cooling your toasty CPU's. Rather than taking the traditional approach of a heatsink with lots of fins and a noisy 7,000rpm fan it uses radiator/heat pipe technology. The implementation of the unit is a bit flawed, but it is interesting to see where the technology is heading.. and if it can be done right I personally think this is where it will end up."
I remember seeing years ago on public television somebody demonstrating this amazing liquid which, I believe, was called "chlorinert". It looked and behaved more or less like water, but it was completely nonconductive. The guy demostrated by plugging in a lamp, submerging it in the liquid, and screwing in a bulb while it was submerged. It was pretty amazing.
They mentioned its possible application to CPU cooling in supercomputers -- the idea was that you would actually submerge whole circuit boards in the liquid, while pumping it through a conventional refrigeration unit. Heat sinks be damned!
Apparently it never caught on, though -- I can't find anything about it online. Even mighty google just says, "Did you mean 'chlorine'?" I think it was incredibly expensive; perhaps that's the reason.
Me: "My computer has been making a strange sound."
Computer Mechanic crawls under my computer, then slides out a few minutes later and wipes oil off his hands with an old shop towel. "Looks like your radiator fan has lost a bearing. I can replace it, but I also have to put on a new belt. The old one is almost wore down. Also, you need an oil change. These new Septium-6 processors can really eat up an oil filter quick, and the color of this stuff is pretty dark now.
Me: "Boy, I remember when computers were so simple, I could just pop off the case and swap out components on my own."
Computer technician: "Ok gramps, whatever you say. You just sit yourself down out in the lobby and I'll have Betsy ring you up once I'm done. Shouldn't take more then a couple hours. Oh, and the tread on your network connector looks a little thin, can I suggest a new pair?"
Twinhead advertising claims that their heat pipe technology is patented. I've no further details and couldn't find anything relevant on their web site.
Buy Windows XP. Give Bill Gates even more of your money.
No this is hopefully NOT where it (CPU cooling technology) will end up. Ideally, it will end up with CPUs that consume less power and give off less heat, can withstand higher core temperatures, and can more efficiently transfer heat outside the core. Slapping a vapor refrigerator onto the CPU is the opposite of elegance.
The reviews are all favorable, but it's not clear whether this is simply because the reviewers are blinded by the "hey, it's neat!" factor, or whether the Radiator Zen SCR325-2F actually has a legitimate technical advantage. But hey, it is neat, so I can't blame them.
The Zen review is on page four.
There is a documented link between low level noise and hearing and stress levels in those spending long times exposed to them.
The hum of a fan, whatever it is cooling, is often at a level that you might strain to hear clearly. It is these levels that can cause hearing strain. This is similar to eye strain when you need glasses and can give you monster headaches.
Many articles in New Scientist, among others, have covered this - normally relating to office environments.
Symptoms can be migranes, and a persistant ringing / humming sound when you are in a silent room / trying to sleep. Its worth checking out if you feel any of these because the long term stress levels can be harmful.
I don't know if its a problem for babies - but I know the effects are magnified many fold if you are exposed for long periods, i.e. all night. So I wouldn't leave the machine on 24/7 even if the baby doesn't seem bothered by it 'just in case'.
I mean, you have a radiator which exposes the same surface area as a typical heat sync, but makes less effective contact with the heat source.
The fluid is probably not doing anything significant at all, the two fans gushing past the aluminum tubes is probably doing all the work.
I don't even think this thing is actively cooling. There doesn't seem to be any pump... they're relying on the thermal gradient to cause the vapourizing fluid to move to the cool side of the radiator and condense. It doesn't work that way. You need to have some way of forcing the fluid to move in one direction, you need to cause the liquid to vapourize by forcing it through a small opening, pulling heat from the CPU.
If you can somehow get around that technical wizardry, then you have to find fluids which vapourize at the temperature of the CPU, but condense at the temperature on the other side of the radiator... whatever wimpy thermal gradient that might be... the pressure of the system also remains constant because the whole system is operating passively of course.
In other words... if you have a CPU at 50 degrees C, and your cooling fluid vapourizes at 40 celcius, then the other side of your heat sync MUST remain lower than 40 celcius, otherwise you just have a bunch of tubes full of pressurized vapour. There is no reason for the cooling side to actually cool especially if the same area is exposed to the CPU as is exposed to the fans.
On the other hand, if your fluid vapourizes at 60C, it doesn't actually DO anything until the CPU reaches that temperature.
This is not to say that passive refrigerators do not exist, I just don't think they've built one. They've built a chunk of aluminum full of fluid with two fans blowing through it.
They should have run another benchmark: Drain the radiator.
Kryotech has this done right.
The average Intel CPU dissipate a waste heat much greater than the few watts absorbed by your average fan. So the idea seems reasonable.
Alas! The laws of thermodynamics often fly in the face of reasonable ideas. See, if you want to passively cool off the CPU, all you have to do is let it radiate its heat. But what you seem to wish for here is some kind of device that actively cools off that CPU, by taking some of that waste heat as its energy source. That's called a thermic engine. And here, thermodynamics get you: You can generate power from a heat source only if you have a cold "sink". All thermic engines work by getting heat from a heat source and moving it to a heat sink. E.g., for a car, the heat sink is the radiator.
Here, your contraption would use the CPU as a heat source and would require some sink, such as, oh, a radiator. Maybe with a fan. Which is exactly what we are trying to avoid.
So it's a nice catch-22. But think about it: if it worked, we would have big ships moving smoothly on all oceans, powered by the extracted heat of sea water and leaving a trail of ice cubes in their wake...
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