Quiet TEC CPU cooling - for the masses

[spinky]

check this out (http://www.pcworld.com/news/article/0,aid,107235,00.asp)

okay..somebody explain to me how the thing works.


i'm not familiar with TEC, never used one, don't plan to use one anytime soon.

but from what i've read from [H]|F last time (yes i'm a refugee) to cool an amd cpu you need about 180W TEC..whereas the AMD generates about 70Ws of heat.

now the TEC in that article (i assume) is 180W.. basically the hot side is around 180W hot? (or somewhere there?) so how the !@# in the world can that fan cool it down?

[Torinalth]

not necessarily true.... an 80W tec wil cool the amd.... but dont expect to raise the vcore and the speed of the cpu..... a 172 will work fine for overclocking and getting you where you want to be.

I personally dont see it worth it unless you get a 226W tec and really get as close to phase change as possible.... and it is more or less just a water cooling system with a TEC to get the chip colder....
Torinalth

[KnightElite]

Basically what they seem to be saying is that the power supply controls the voltage accross the TEC to maintain the CPU temperature at 22ºC. And as to the fan, it doesn't really have to cool it very much.... only enough for the CPU to stay at 22ºC. Presumably they don't care how hot the hot side of their TEC gets, as long as it's cool enough to keep the CPU where they want it. I doubt it would be of any real use for overclocking.

And as to TEC cooling AMDs, any TEC larger than 120W should do the job for decent overclocking, at stock speed & voltage, with a 156W TEC my setup stays at about 5ºC (it would be better with a 226W). Also, you have to keep in mind that a TEC actually outputs more heat than it transfers, so a 226W TEC is rated at 15.2V 24A, which means it will be outputting 365W of heat if it is run at max voltage/current, plus whatever heat it transfers from the CPU (assume say 80W). TECs are not efficient at all.

[docah]

The heat output is massive from the tecs.

"Because the thermoelectric unit is doing most of the cooling work in the system, the CPU fan typically runs at half-power, drastically reducing noise." <- I'll have to see ti to believe it... and even then i'll deny that it's true.

[spinky]

KE >

" And as to the fan, it doesn't really have to cool it very much.... only enough for the CPU to stay at 22ºC. Presumably they don't care how hot the hot side of their TEC gets, as long as it's cool enough to keep the CPU where they want it. I doubt it would be of any real use for overclocking."

so in that case, the heat from the TEC isn't really cooled, then wouldn't the heat sorta "cook" everything else in the case? rise the tempreture of the air in the casing? mmm.. sounds VERY inefficient.

[Tedinde]

I do not see this doing very well in real live. You would have to leave the side off your case at a minimum. And I doubt any overclocking or extra volts.

[KnightElite]

Originally posted by spinky
KE >

" And as to the fan, it doesn't really have to cool it very much.... only enough for the CPU to stay at 22ºC. Presumably they don't care how hot the hot side of their TEC gets, as long as it's cool enough to keep the CPU where they want it. I doubt it would be of any real use for overclocking."

so in that case, the heat from the TEC isn't really cooled, then wouldn't the heat sorta "cook" everything else in the case? rise the tempreture of the air in the casing? mmm.. sounds VERY inefficient.

Basically, that's right. The CPU stays moderately nice and lukewarm, but the case will heat up WAY more than with just a regular heatsink. And the heatsink will probably be quite hot as well.

[DRaG0nBLaD3]

Seems like a great time to use one of those heat pipes, you know, the ones that cover the cpu and go straight to a rear fan?

Anyway, saw the product link for this on TT's site today, before I even read this, and thought it was kindof an interesting thing...using a processor to control how much work the TEC is doing...seems a bit more efficient, powerwise and noisewise.

http://www.thermaltake.com/products/subzero/subzero4g.htm

[antipop]

I don't know if that will be efficient or even if that will work. I don't trust anything that TT makes

[NoEcho]

We discussed something very similiar many months ago on the Hardforum. I thought it would be great to adjust a TEC"s output so it kept the cpu just above dewpoint... thus bypassing the need for condensation prevention.

This might be TT's objective, though their approach is more basic, 22 C being the cutoff. Maybe that's the average dewpoint in Asia.

Aircooling a TEC is - far as I know - a really bad idea. I think the TEC loses its capacity to cool the hotter its hot side gets. It's efficiency drops in something like a geometric curve with temperature. As the efficiency drops, the heat generated increases and at a certain point it absolutely flips into a feisty little heater.

That said, a temperature adjustable voltage device sounds like a good idea. Maybe combined with heat pipe technology they actually could do it without water. Course there's no way you'd want that thing running off the system's PSU.

[Tedinde]

If this is just varying the voltage it's probably ok. If i remember, Cycling the TEC on and off, is not good for it. There used to be a TEC controller about 2 years ago for sale that had all kinds of problems and burn TECS out by doing this.

Anyone else remember it.