Peltiers

[Judd]

First off, if you do not know what a peltier is I’ll explain it.

 

a peltier is basically a block of insulators and ceramic and other metals that when electricity flows through it one side will get very hot, and the other equally as cold. What I want to do is use this cold side to cool down a liquid(not water) to sub-zero temperatures. Now these peltiers use a LOT of energy. They range from 60W to about 500W. What I want to know is, would this be a feasible idea to get sub-zero temperatures without LN2 or a phase change cooler as phase change coolers are loud and big and LN2 requires pouring it over the CPU directly every couple of minutes. Here is an example of a peltier. 

https://www.amazon.com/Agile-Shop-TEC1-12710-Thermoelectric-Cooler-Peltier/dp/B01MQZ6C0L

[Radium_Angel]

I used them extensively in the 486 days, but they fell out of favour as cooling fans and water blocks improved. I haven't seen a peltier in use in decades

[intender]

I played around with peltiers back in the early days of the athlons and durons.  I am not sure that you could cool one well enough to reach sub-zero temps.  even with it running without a load on it even the medium size ones will struggle to get down to about 10C if your ambient temps are around 25C.  You have to be really careful when using a peltier because the hot side needs to get hot for the cold side to get cold, but if you produce more heat that your cooling solution for the peltier can handle the you get a thermal feedback loop where the cold side will get hot enough to boil water after a while of use.  you could use it as a water chiller setup for a custom loop, but you would still have to use something seperate to cool the peltier.  and then you will run into problems of the water freezing inside the loop somewhere.  or chunks of ice clogging the loop, or even cracking your waterblock if it gets too cold.  I would imagine you would need something like a 300 watt one to work on a modern cpu, maybe even more than that. 

[Judd]

48 minutes ago, intender said:

I played around with peltiers back in the early days of the athlons and durons.  I am not sure that you could cool one well enough to reach sub-zero temps.  even with it running without a load on it even the medium size ones will struggle to get down to about 10C if your ambient temps are around 25C.  You have to be really careful when using a peltier because the hot side needs to get hot for the cold side to get cold, but if you produce more heat that your cooling solution for the peltier can handle the you get a thermal feedback loop where the cold side will get hot enough to boil water after a while of use.  you could use it as a water chiller setup for a custom loop, but you would still have to use something seperate to cool the peltier.  and then you will run into problems of the water freezing inside the loop somewhere.  or chunks of ice clogging the loop, or even cracking your waterblock if it gets too cold.  I would imagine you would need something like a 300 watt one to work on a modern cpu, maybe even more than that. 

The one I plan on using is a large 527watt one. And I plan on having a 480 Rad to cool the peltier only. I would really like to experiment with these as I find them very interesting especially if I can get the to work correctly. I do have one question; the lets say 300watt rating, does this mean there is 150watts of heat on oneside and 150watts on the other? Or is it 300 on each side?

[intender]

The power rating can vary depending on whether you are buying a cheap chinese brand with crap ratings or a nice high dollar unit.  The way I always thought it worked was that the Watt rating was the hot side heat production.  But some of the cheap stuff will label it as actual power draw.  Also you should find out what the actual power draw is and the delta T is.  delta t is the temperature difference its capable of between the two plates.  so if your TEC has a delta T of 60C and your ambient is around 25, that doesnt mean that your cold side is going to be -45C.  Your radiator is also going to have a delta T.  This info may not be exactly correct, but I think most high quality radiators are capable of cooling roughly 200 watts of heat per 120mm section with around a 10C delta.  so your 480mm rad if its a good quality rad would be able to cool around 800 watts with a 10C detla.  so you should be good heat wise, but once you throw the system into the mix you might see temps somewhere around 10-30C below ambient.  But in reality it could be less improvement than that.  I was going to type out a long explanation explaining the heat dissipation of a TEC, but it was way to scattered and hard to read after I started typing it for my adhd brain to try and organize it into something useful. 

What kind of power source are you going to use for this.  most TEC's that people use in pc's are rated at around 15v.  It could be less or more than that, so make sure of that.  At 15v thats around 35 amps of power draw.  If you use a 12v power supply you are actually going to be providing around 400W of cooling I think. 

[Judd]

1 hour ago, intender said:

The power rating can vary depending on whether you are buying a cheap chinese brand with crap ratings or a nice high dollar unit.  The way I always thought it worked was that the Watt rating was the hot side heat production.  But some of the cheap stuff will label it as actual power draw.  Also you should find out what the actual power draw is and the delta T is.  delta t is the temperature difference its capable of between the two plates.  so if your TEC has a delta T of 60C and your ambient is around 25, that doesnt mean that your cold side is going to be -45C.  Your radiator is also going to have a delta T.  This info may not be exactly correct, but I think most high quality radiators are capable of cooling roughly 200 watts of heat per 120mm section with around a 10C delta.  so your 480mm rad if its a good quality rad would be able to cool around 800 watts with a 10C detla.  so you should be good heat wise, but once you throw the system into the mix you might see temps somewhere around 10-30C below ambient.  But in reality it could be less improvement than that.  I was going to type out a long explanation explaining the heat dissipation of a TEC, but it was way to scattered and hard to read after I started typing it for my adhd brain to try and organize it into something useful. 

What kind of power source are you going to use for this.  most TEC's that people use in pc's are rated at around 15v.  It could be less or more than that, so make sure of that.  At 15v thats around 35 amps of power draw.  If you use a 12v power supply you are actually going to be providing around 400W of cooling I think. 

I was going to use a separate PSU for the peltier. So with the delta -t. Say it has a 60C delta-T and my ambient temp is 20C. Does this mean the peltier can theoretically get down to -40? Also, the reason why I asked if the wattage is split between the 2 sides was because I wanted to know how many watts the peltier can cool down before it is overloaded. And Yes, I plan on buying a high quality one with a rating of 524watts. Bu this is how many watts it pulls form the PSU. I could just get multiple and stack them together.