What ever happend to Peltiers?

Hey guys,

Back when i was still overclocking, or rather trying to cool my pc alot, i came across Peltiers.

From what i remember and my understanding, a peltier can cools on one side and heats on the other, and runs on 12v.

These were used to stick straight onto the CPU and then a heatsink with fan ontop to cool the hot side of the peltier.

This didnt produce freezing temps, but it did cool more then the average air system.

What i would like to know is, has their been any change in this technology? Why dont we use them anymore? Pros and cons of peltiers.

For those with no clue: http://en.wikipedia.org/wiki/Thermoelectric_effect

Hoping for some good response.

I wont discount the ability for them to reach lower temps, but now you have to take 2 TIMES that ammount of heat off the other side of them.

When the "wattage" is very high (per inch) that your trying to extract heat from, the semiconductor array has to be very close together to do that much work, making the surface area on the "hot" side very difficult to cool. If you dont cool the hot side LOTS , the hot side just heats up the cold side, and you end up putting a heater on there The Delta.

because of the way the semiconductors need to be positioned (thickness), the hot side cannot be moved further away from the cool side, so there is limited seperation from that heat being able to head the wrong direction. Again, it is just nessiary to get the hot side very cool.
With all the extra heat, there is going to be more heat generally around there that will not get transported, heating up the case. and the voltage regulation around the cpu.

not only do you have the ~2x heat on the hot side, but you also have to feed the peltier with as much power as is being removed so you have to supply a rediculous ammount of power , which should do a good job of heating up any low efficency power supply.

100watts of fan would do a pretty good job of cooling with the right heat sync on AND you still are going to have to have fan to get the heat off of any heat transporter on the other side. I attempted a "passive" heatsync of the hot side and the sink was 2 Feet big. it was not untill i put a fan on the heat sink that i could move enough heat. A water transport method, would still have to have the water cooled in some way.

myself i do not like the in and out surfaces of the ceramic based peltier style i tested, they have to have an electrical insulator, and i did not feel that it was the greatest thermal conductor.

it could be that lots of my problem was that it was one i got off the web, even though it was not cheap at all.

that leaves, assuming that you can cool the hot side completly, the cold side not only condences water on it, but it seems to Love to condence water on it but that isnt anything that extreeme overclockers havent dealt with before.

a Compressor based freon heat pump is more efficient and the distance that the heat is transfered is much further away. although it is large and has hard starting, it would be a better choice , just like it is a better choice in freezers and fridges. and they are capable of working passive because of a much higher delta ability, (although they would still work a lot better with a fan too).

which just leaves my question, why not cool the bottom of the core of the processor too
.

This thread really should be in the extreme cooling section, but I suppose its good here too.

I think the reason you don't see them much anymore is that they stopped adding larger units. The older TECs went up to 200w, iirc, and many of our current cpus will go past that point easily. It was always a niche market so I'm guessing it wasn't worth it to them to build larger units.

Daemonkin said:

This thread really should be in the extreme cooling section, but I suppose its good here too.

I think the reason you don't see them much anymore is that they stopped adding larger units. The older TECs went up to 200w, iirc, and many of our current cpus will go past that point easily. It was always a niche market so I'm guessing it wasn't worth it to them to build larger units.

Click to expand...

Yep, this pretty much sums it all up. Plus, peltier cooling is pretty darn inefficient at the heatloads of today's processors.