Peltier Blocks

[kizzap]

does anyone have any designs for waterblocks that would be suitable to cool a 50mm peltier that can be build out of 3mm copper sheet? I can only get 3mm copper sheet here and i was lucky to be able to get it. at the moment i am desperate to find a suitable design.

[killernoodle]

a #rotor block might still be your best bet, but I'm not sure if you could effectively do that in 3mm copper.

[prandtl]

no way you can do a #rotor block with 3mm copper plate (the one with pins). Tho there is another pelt block design on his site that you could do. (bookmark dead)
As far as i remember, it was only using to flat plate with a solder gasket, dont know how it performs tho.

[JFettig]

you sure could do it, it might be a little restrictive.

The only problem it seems you have is you need much thicker material for the cold plate, Im talking 10-13mm thick.


Jon

[Les]

Originally Posted by JFettig

The only problem it seems you have is you need much thicker material for the cold plate, Im talking 10-13mm thick.


Jon

It looks like a definitive statement.
Evidence?
Theory or definitive Bull Shit?

[kizzap]

I have looked at the #rotor waterblock design but I don't actually understand how it works...

also why woul i need 10-13mm copper for the cold plate...I was under the impression that it is best to use something smaller?

[FL3JM]

Well in order to have pins that stick out of the baseplate you need a thick chunk of copper. You cant just solder the pins on or something, that would degrade the performance extremely.
The #rotor design is the easiest since you just drill holes and then use a dremel or something to make channels between those holes, that way you get a lot of channels around a large amounts of pins.

Remember, you want alot of copper surface that can touch the water, you can try make a rotor out of that 3mm copper plate, but the pins will be extremely small. You will get a block where the water runs above the pins, which might work for a low effect peltier, i dunno, but the real #rotor design is made so that the water is forced to run between the pins since the top of the block covers the top of the pins. If you try something like that on a 3mm baseplate your block will be HEAVILY restrictive since the channels will only be like 1,5mm high.

[kizzap]

i have found a block design that might be possible to use here. does anyone have any Ideas or comments on the block design?

[SlaterSpeed]

You know thats exactly what i was about to suggest

You will need a thicker cold plate or else heat from the small die cannot conduct to the outer edges of the pelt and it wont work very well at all. Jon does not BS!

[jaydee]

Originally Posted by Les

It looks like a definitive statement.
Evidence?
Theory or definitive Bull Shit?

You should know more on the subject than most of us put together eh? You tell us? :shrug:

[BillA]

no, Les does know more
but Les did not make the assertion, so not his problem to defend or disprove

nor jd, do I believe you understand the question; can you state it ?

[Les]

Originally Posted by jaydee116

You should know more on the subject than most of us put together eh? You tell us? :shrug:

Cannot give a definitive answer.

The theory is that the optimum Cu thickness is dependent on Peltier area and Film Coefficient(h) - Waterloo .
Bill Adams had the first crack at this 3yrs ago - Thickness .
Since Bill's effort there has been no advance in identifying the correct h.
Here I have tentatively suggested that h can be equated to the heat-sinks Thermal Conductance .
Without a value for h the optimum theoretical thickness cannot be calculated.

The only experimental work I have done - here - did not add to my understanding

[killernoodle]

Originally Posted by kizzap

i have found a block design that might be possible to use here. does anyone have any Ideas or comments on the block design?

Now that is an interesting design. Looks like a zalman heatsink type design. I wouldnt do it in that particular way though, You would be much better off if you drilled many tiny holes for the water to run through than just 3 large ones. I think Cathar did a cross drilled waterblock with many many small holes running parallel through the block. Really, you would need 2-3 plates for the barbs, then a couple of open ones, then the middle would have the many holes, then a couple of hollow ones to allow for the water to make the turn, then a solid one to close it off.

[jaydee]

Originally Posted by unregistered

no, Les does know more
but Les did not make the assertion, so not his problem to defend or disprove

nor jd, do I believe you understand the question; can you state it ?

He doesn't? What about all the testing he goes on about then?


The question is easy, no?

Originally Posted by JFettig


The only problem it seems you have is you need much thicker material for the cold plate, I'm talking 10-13mm thick.


Jon

Implies the cold plate needs to be thicker than the 3mm material kizzap has will not be sufficient for the cold plate.



Then Les said:

It looks like a definitive statement.
Evidence?
Theory or definitive Bull Shit?

Implies Jfettig has no evidence to support that the 3mm material is not sufficient for a cold plate and/or the 10-13mm thick material Jfettig threw out has no evidence to be proven correct.


Les, thanks for the answer and I was correct IMO. You do know more than most of us put together on the subject. Your statment is proof as I bet 98% of all members on this forum had no idea that "The theory is that the optimum Cu thickness is dependent on Peltier area and Film Coefficient(h) -" was even in the equation. I have been doing this for over 3 years now and had no idea myself.

[BillA]

jd
my error, I misunderstood; thought the geek was trying to associate a thinner wb bp with the need therefore for a thicker cold plate
- not so I see now

[kizzap]

am i being called a geek here?

[Les]

Originally Posted by kizzap

am i being called a geek here?

Think not.
Suspect is a reference to JFettig.
He was previously posting as maskedgeek - here for example.

[Khledar]

What about somethign along the lines of a #rotor block. Har - not what you're thinking though! I remember there was block #rotor made which did not use the pin style, but two sheets of Alu. I think his specific application was TECs too, it's an old concept but might work, it was very simple, however #rotors site doesn't seem to be up and my memory kinda sucks. But if I remember it was essentially two sheets stacked with some sort of wire soldered (probably somethign else for Alu, but some low guage copper wire would work prostyle for this) just inside the perimeter of the plates to create a gap between the plates, the inlets and outlet were just in the top of the block - no channeling - very simple just a very thin rectuangular water cavity essentially, probably no performance machine, but effective, also easily adaptable for larger surface area (TEC).

Maybe someone remembers the idea more clearly than I.

[kizzap]

ok forget the block design for a sec..I got a different question to ask

what would be the best way to have the water flowing through the system?

I was think of having the water go through the pump then through the heatercore and then onto the CPU waterblock. now at the water block i was planning on splitting the water path in two making one go to the mobo chipset and the other go to the graphics card. then they would both meet up again and go back to the pump

also another question is what size tubing should i use to get the best flowrate and cooling capabilites?

[Jabo]

Originally Posted by Les

Cannot give a definitive answer.

The theory is that the optimum Cu thickness is dependent on Peltier area and Film Coefficient(h) - Waterloo .
Bill Adams had the first crack at this 3yrs ago - Thickness .
Since Bill's effort there has been no advance in identifying the correct h.
Here I have tentatively suggested that h can be equated to the heat-sinks Thermal Conductance .
Without a value for h the optimum theoretical thickness cannot be calculated.

The only experimental work I have done - here - did not add to my understanding

I checked your link to Waterloo calculator. In restricted time frame I couldn't find equations governing each of the cases exibited.
My hint is to start from comparing spherical spread results/input data needed and cubical ones. From what I can tell your mysterious h is only dependant on geometry of our cold plate.

Imagine the cold plate being infinite in X & Y axis but Z axis(thickness) is adjustable. What would be your Z dimension to achieve optimum performance?
Try to draw 3-D temp gradients representation to achieve the ideal 3-D geometry of cold plate.
Just my 2 pennies

[Les]

Originally Posted by Jabo

........
1)My hint is to start from comparing spherical spread results/input data needed and cubical ones.
2)From what I can tell your mysterious h is only dependent on geometry of our cold plate.

Imagine the cold plate being infinite in X & Y axis but Z axis(thickness) is adjustable. What would be your Z dimension to achieve optimum performance?
Try to draw 3-D temp gradients representation to achieve the ideal 3-D geometry of cold plate.
Just my 2 pennies

1) There are no results to compare. It has to be done theoretically.
2) No. It is independent. It is determined by the pumping characteristics of the Peltier

[Jabo]

The way I look at the problem is that the only variable is geometry of our cold plate, all the rest is constant and therefore has no influence on the outcome/3D characteristics of the cold plate.
Yes, you are right, with different peltiers you will need different cold plates and for each combination of 'block side' set of characteristics and 'cpu side' size/thermal output there is one optimal shape of the cold plate.

What I am saying is that for a prticular setup there is only one best 3D shape of a cold plate providing the best performance for given material.
Performance of the whole assembly with only variable being cold plate (we stick with Cu here) is only governed by its shape, which pretty obvious.
Now, how to arrive at this 'shape'?
Start from ideal conditions being cpu die in perfect vacuum and what happens with its thermal output, where and how energy propagates. then introduce an environment and make it also uniform (same as perfect vacuum but with additional set of 'modifiers being properties on a material defining our environment). We are talkin here about the half of infinite space represented by half-sphere.
It is certain that at particular distance from energy source measurable value of emitted energy is going to be so close to zero that for our purposes it is going to be zero. This boundary condition is important for us.
now imagine the same thing but for TECs cold side.

Shapes of 'energy clouds' each of them are different. For now thay are at infinite distance from each other and have no influence on each other.
Start decreasing the distance between the two (treating enviro. as one).
At some point 'thermal energy clouds' of different polarity (lts say hot is + cold is -) will start to overlap.
We are interested in the 'overlap' condition. Cals are simple here (I am still at theoretically perfect situation where there are no external influences contaminating test universum). It dead easy to calculate temp of each point within 'tec' (thermal energy cloud) for each source. Where they overlap we simply do some adding to arrive at effective temp.
At this stage we need to introduce time and thermal energy pressure (thermal gradient dependant) to establish the ideal distance between two sources. Shape will be decided by the oputcome of isotherms interference pattern.
By examining this model I concluded that the optimal distance is where isotherms of both sources meet at their 'flat fragments' and are equal in size (plains). Due to TEC modules isothermal plain is 'wider' than CPUs at the same distance from each of them, distancee from CPU is going to be longer than that from TEC to allow CPUs 'tec' to expand to needed width (the further from source the larger the plain and we want it to be as small as possible).
I hope it is cogerent nuff to be digestible.

Please do not reply saying that I am desribing things extremely basic since they are not for all members

If you want to b0llock it do it constructively. please

P.S. Experimental methodology is pretty neat. Use moulds for shapes and lead to replace Cu since it is easily obtainable and melts even easier. To create a moulde use sth like clay-like material and plywood shape cut-outs axial initial shaping. The whole thing is easy but requires massive amount of time and workman hours...

[jaydee]

WTF are you talking about? Why not just get a chunk of copper and mill it down mm by mm and test each step. To hell with methodology. Will take 10 times longer and the results will still have to be proven with a actual prototype. Why make things more compicated than they need to be....

[Jabo]

Originally Posted by jaydee116

WTF are you talking about? Why not just get a chunk of copper and mill it down mm by mm and test each step. To hell with methodology. Will take 10 times longer and the results will still have to be proven with a actual prototype. Why make things more compicated than they need to be....

Oh, don't mind me then d00de. Just keep shoving chunks of copper into your mill if that tickles your fancy Without theory and basic mental constructs building ability human race would still be in stone age
But seriously, as you righlty remarked, there is alwyas more than one way of skinning the cat. I simply do not have time for trial&error methods of engineering...
I never make prototypes, it has to work off the bat, or workbench If I do anything myself (very rare occurances) it represents the best the current state of my theory can produce at given moment. I am not saying it does not evolve, of course it does!
As far as time taken to 'think it all up'.... well I'd rather stop here

[Butcher]

Originally Posted by Jabo

Oh, don't mind me then d00de. Just keep shoving chunks of copper into your mill if that tickles your fancy Without theory and basic mental constructs building ability human race would still be in stone age

Actually I think you'll find we progressed well past the stone age without much in the way of theory. Iron for instance was discovered by luck rather than any theory that red rocks might produce a useful metallic element when heated.