Mixing Phase change & peltiers

[PMM]

1st Hi to all - not a regular poster but most certainly a long time lurker of this forum.

I'm not currently in a position to venture in to building my own phase change and TBH while I understand all the principles and mechanics behind it all I'm not going to unless I put myself through a Hvac course 1st.

Anyhow used to be many years ago very into the overclocking scene but stopped when it started getting a tad too expensive for me after x amount of busted Gfx & CPU's from pushing too far with vmods and such like.

I have currently doing nothing a Prometia <sp?> & Vapo-chill phase change units from days gone by when I built my doublecoolermaster unit.... http://brittech.co.uk/casemod.htm & http://brittech.co.uk/mypc.jpg mix of phase and water cooling.


Getting to the point..... I know these units will not even cope with current CPU's but what if I gave the Phase unit some help in maintaining the temps with peltiers or going a stage further Phase + Pelts cooling another Pelt close the the CPU ?

This is what is in my head (Could be something totally barmy) but something I quite fancy trying if deemed potentially workable....

I'm I barking mad ?

Below is basically 1 pelt cooled by Phase with 2 pelt watercooled.

[LukeXE]

From what I know, if you will cool peltier too much it won`t give you better results. This is not good way my friend

[killermiller]

What are those watercooled pelts on the sides supposed to be doing?

[PMM]

I'm aware the Pelt nearest CPU will be running less efficient in that pic below if it were setup that way, I have heard of phase change systems (Powerful ones) that have employed the technique of using a pelt to get it a tad colder but thats something I read years ago.

To explain further.... ( Forget the Pelt nearest the CPU for now )

My idea is a central block that is in essence a cold block like a cold plate in std pelt + Water cooling scenario.

The Cold Block Contains clamped within an existing Phase Change head from one of the machines.

Because I know that alone it will not hold a CPU load of a modern chip the idea is to have Water Cooled Pelts in effect helping keep the Cold Block (Cold).

On the principle the Phase Change bit will take a good portion of the heat away my logic being that the pelts would not be dealing with the same heat loads on the cold side therefore potentially maintain a decent cold block temp working with the phase change.

If that makes sense ? as said its kind of something interesting in my head... I understand it from a water cooling side & I understand phase change but if doing what I want above will work or not is something different in that would it stop the phase change from boiling off ? its a bit like subcooling in my mind.

Its been a few a year and I'm interested in getting back to some good old tinkering

Started a Heat load tester a few years ago but stopped computer fun before completing it.

Designed to be multi-purpose in taking any heatsink / water block / phasechange head with an additional twist of changeable heater head with die sizes to match that of CPU's think I made the heater rated 400Watts at 48v think it gave about 60w at 12volts ... http://brittech.co.uk/testdie1.jpg quite a bit to finish off its just gathering dust in the garage.

basically its time to start having some fun again just an idea on the table for discussion with those brainer than me

I quite fancy the pelt near the CPU for long term running in that I'd be interested in using it as a thermal stabiliser to maintain a set temperature and have it throttle up and down with CPU load, I realise that this might be stretching the capabilities and is a secondary thought to the initial idea but if Phase + Plets could provide enough cooling where it can cool a pelt to provide extra cooling I'd quite like to factor it it.

[mike8913]

I think it's very interesting and worth an experiment but with todays chips using less and less wattage and the increasing difficulty in insulating low temperature solutions that an added peltier with water cooling clamps popping out of the sides is just not worth it. On the other hand I would still love to see it done just for s and giggles.

[n00b 0f l337]

If you really want to employ it, the best gains will be a peltier circulating/sleeve block around the discharge line as it leaves the condenser. (liquid line). Basically an air cooled 30mm 60-70watt peltier cooling the liquid line (thin coldplate brazed on or something) will and has worked.

[PMM]

ahhhhhh you just reminded me of something I did a long long time ago

I joined a plate to the copper piping after the rad when experimenting with using the vapochill unit on the Prommy forgot I did that.

[AliG]

dog, can you say power consumption? TECs are terribly inefficient and not to mention each phase will run you at least 200w, we're saying 1kw minimum, expect even higher

sorry, but I just can't see this being applicable, tune your phases to be stronger instead, replace the charge, modify the cap line, random things like adding an slhx (or even soft soldering the cap to the filter/accumulator)

[[XC] gomeler]

Yeah, powerconsumption from TECs just hurts to look at when compared to the performance. Now what I want is to be able to harness some of the heat thrown off of the compressor shell with a TEC and an air-heatsink to power the fans running the unit. Ahh, didn't think of that, now did you Going to try this in a little bit, need to see what it'd take to generate maybe a dozen watts around 12v. "green" cooling in a sense

[PMM]

I thought pelts really sucked when dealing with a high load and where the load was less the deltaT improved as loading decreased.

My logic was that the Prommy would in essence shift the bulk load of the heat
lets say 75&#37; just for discussion purposes leaving 25% to be removed by 2 water cooled pelts If the Heat Load was 100W and the prommy could handle say taking 75W before nose diving substantially the 2 pelts would only have to say handle 12.5W of heat load each which essentially would see quite a good DeltaT compared to a single pelt taking a full 100W load.

[STEvil]

Phase cooling high-power tec's might get you somewhere.. you would have more surface area to play with.

[hakemate]

I think that project its interesting, but it&#180;s very dificult to build, and the temps you&#180;d get aren&#180;t lower that a simple phase change evaporator, or not far...
But if you want to do it, i want see it!! It&#180;s very interesting

[PMM]

My only concern - which is one I wanted to try can get answered off the phase change professors here is this....

Being really two different technologies if it was in a low load situation where the cooling performance exceeded the pelts performance.....

Could the Phase Change section end up dragging heat back through the peltier ? I.E. Its own generated heat back to the coldside.

Apart from that yes a little bit complicated in the metal work - but I have idea's to simplify and good friends in our works engineering dept.

Pretty sure they won't let me bleed off the Co2 & Nitrogen from the Nitrogen/Co2 tanks though

[[XC] gomeler]

Peltiers operate by creating a thermal separation, so as long as the peltier is powered then it'll continue to shift heat from the coldside to the hotside as long as the heat is continually removed from it's hotside. This is why you can't make enormous peltier sandwiches as you eventually overload the upper peltiers and the entire system crashes, but with a single, powerful peltier and an evaporator capable of removing the load, I imagine you'd see some results. Remember that you must be capable of removing the load of the peltier and the original heatload so at 200w on the cold-side you could be looking at 400w+ on the hot-side.

[AliG]

exactly, so not only would power consumption be skyhigh, but also you'd be tuning a phase for extremely high loads instead of just getting good temps without the peltier

[PMM]

Yes but you would not be loading the pelts with that much load if the phase cooling is included taking the bulk. (Remember ignore the bottom pelt) That just a side idea.

As said above if your Heat load is 100W The phase change is going to take a good portion of that heatload the remainder to be handled pelts.

If the phasechange takes 75W watts of heat away your only dealing with 25Watts of heat load shared by the number of pelts.

Your not going to have to use silly power pelts for that 25Watts

If its divided by 2.. each pelts heat load is 12.5w its could be expanded to a 4 way design then its only 6.25w load per pelt.

Anyhow I am much more confident now you explained the pelt mechanics of heat only going one way as long as powered up :thumbsup:

[AliG]

no you're not looking at it the right way. There won't be any phase taking a good portion of the heatload. What will happen is the cold side of the tec will cool the cpu and then the phase will cool the tec, you'd need a damn strong phase setup to cool 400+w in order to cool both the tec and auxiliary cool the cpu

[PMM]

Ignore that bottom pelt take that out

Just think cold block Phase + pelt to cool CPU that's the bit I am only interested in I don't want the phase change to interfere with the pelts which by the explanation earlier should not be the case.

[SNiiPE_DoGG]

it seems to me that if you were to use a pelt on the CPU it would need to be a 400 watter, IMO thats a gigantic waste of electricity, if your houses circuits can eve handle the pelt PSU + comp PSU + Phase unit going all at once. You would probably have to run some extension cords...

[AliG]

I think you would be best off giving the two phase units to a builder to mod into a cascade of some sort, it wouldn't be the world's strongest cascade, but it would definitely give you lower temps and higher capacity to the least

[killermiller]

The phase would proably be colder and will be absorbing the heat(less cool) from the pelts and will be technically cooling the pelts and the cpu. The only thing that might work would be what gomeler suggested.

[STEvil]

the tec's on the side in your proposed setup are useless, they will not get cold enough.

The one on the bottom is the only one that will be of use.