Need thoughts on Block Design for 2 loop system

[SparkedFire]

I have two possible designs for a waterblock. the waterblock will be a chiller.

[========] waterblock (cold)
[--------------] peltier
[========] waterblock (hot)

This will be a two loop water cooling system for my CPU. The first loop will be the cold loop, and the second the hot loop. A pelt will be sandwiched between two of one of my blocks. The hot loop will be cooled by a radiator, and the cold loop cooled by the hot loop. Here are the blocks.




Please give any ideas or thoughts to by WB or cooling loops, below is the diagram of the cooling setup.

If you are having trouble viewing the block pics, click here.

[Myten]

why ?
you'd probably get better results putting the pelt on the cpu. (and if youre planning to do so also read the following)
to make a waterchiller of pelts is probably just hardwork for mediocre results. the money is better spent on compressors or better radiators.

[SparkedFire]

There will also be a pelt on the CPU, sorry I did not tell anyone that. Similar users on ProCooling have achieved -40' CPU temps. The peltier chiller would also be more compact, as I would like to keep the system "in" the computer so that I can easily take the case anyware.

[Since87]

Originally posted by SparkedFire
Similar users on ProCooling have achieved -40' CPU temps.

Not likely.

Not a chance in hell, if you are only talking about using a total of three pelts on any cpu faster than 1GHz at full load.

I'd suggest you read
this thread.

[bigben2k]

Agreed. As I remember, even the Brazilian multipelt pyramid didn't do it.

Either way, it would be far more energy efficient to go with a phase change solution, to reach those temps.

[SparkedFire]

ok, thanks guys. Still looking for opinions thoe.

[msv]

Multipel pelts sound to eat a lot of electricity. Except for the PSU for the motherboard, would another PSU be enough for multipel pelts?
OK, depend on the pelts, dual 70W shouldn´t be any problem, but, as in this case, dual 226W?
BTW, how much current has been pushed through those thin cords from the PSU without accidents? They don´t look like they can handle too many Amperes.
regards
Mikael S.

[8-Ball]

OK, I just asked about power ratings in the peltier forum. Combining the responses to that with what you are asking, I will try and answer.

I will say thankyou to robotech now for helping me to understand this.

Lets take the Swiftech 226W TEC as an example.

226W is the Q Max, ie the maximum heat it can "move" (for want of a better word), though this will only be achieved with zero temperature difference. This means the hot side and the cold side will actually be the SAME temperature.

The maximum delta T that this TEC can achieve is 67 degrees, though this is with ZERO LOAD.

Much like pumps used for water cooling, where manufacturers quote the maximum pressure rating with NO FLOW, and the maximum flow rate with ZERO resistance/load, the real world situation is somewhere between these two scenarios.

By that I mean that a TEC rated for 226W Q Max (no delta T) and 67 degrees max delta T (no load), will actually remove the 70W from your processor with a greatly reduced delta T, probably around 30-40 degrees, (lets say 40).

Now looking at the specs of the Swiftech TEC, it gives V max as 15.2 V and I max as 24 A. This equates to an input requirement of 365 Watts.

So in this scenario, the waterblock will need to remove 365 + 70 = 435 Watts from the hot side of the TEC

This heat will be, hopefully passed into the water, which you are hoping to chill with some kind of peltier water chiller.

Now the whole purpose of this project is to have the water passing through the CPU block cooler than could be achieved with just a radiator. So lets say for arguments sake that you would like the water going through the cpu block to be 40 degrees cooler than the water passing through the rad. For this temp difference, each of these 226W rated pelts would only be able to move 70W of heat from the cpu water.

However, we have already established that the pelt on the CPU block is transferring 435W of, so we are going to need six more 226W pelts to remove this heat from the cpu water, (and this assumes perfectly efficient waterblocks on the pelts!!!!!!)

So now you need a radiator capable of dissipating 6 x 435 = 2610 Watts.

Looking at the lytron site, it can be seen that the 6320 rad, which is the HOOOOJ rad some people here have bought off ebay, with a coolant flow rate of 1.5gpm, and airflow of 500cfm, as provided by the stock fans (big muthas!!!) can dissipate roughly 130W per degree of delta T between coolant and air.

So, the coolant would be 20 degrees above ambient!!!!

Lets assume that ambient is 25 degrees C, then the water would be 45 degrees C on the hot side loop.

Now assuming the 30 degree delta T at both pelt stages, thats a total delta T of 80 degrees.

This gives a processor temp of -35 degrees, and as previously stated, this assumes perfectly efficient waterblocks!!!!! So in reality, the temp will probably be quite a bit higher( probably around -20 C).

The cost of this cooling would be 7 226W tecs probably between $150 and $200. But you will be paying for 2.5 kW drawn from the mains plug.

Is it really worth it?:shrug:

Particularly when you could get a vapochill for what, $500-700 (I don't know how much they are these days) which will give you a lower temperature. Then there's the cost of 7 meanwell or equivalent power supplies.

MSV, to answer your question, no you can't really use regular PC PSU's as for starters, I don't know of any that have 365W on the 12V line, plus thats only 80% of the max voltage. (granted, the pelt is more efficient at this temp, but the overall temp over the proc would still go up)

Also, regular PSU's are designed to have a draw on the 5/3.3V line as well as the 12V. Just running a TEC alone would throw the regulation out, which could damage your TEC.

Then there's space considerations. THe chiller would be quite big, 150mm x 100mm at least, plus the 7 power supplies, which are slightly larger than a CD-RW drive, and a radiator which would be happy on the front of a truck.

AND, you'll be pumping 2500Watts into your room. That's as much as some electric fires!!!!!

Hope I have made my point.

A lot of people have been asking about various combinations of pelt chillers and pelt blocks and so on. If you insist on using pelts, stick to putting them on the cpu, or go phase change.

8-ball

[Alchemy]

How surprising to get such an informed post from an Oxford student! (professor?)

Bit of an overestimation of the power consumption of the pelts, but as you note yourself, you're close enough to make your point quite clearly. Pelts are inefficient, and stacking them like this multiply that.

Good research, good math, good terminology. Very nice indeed.

Alchemy

[hara]

So now you need a radiator capable of dissipating 6 x 435 = 2610 Watts.

You could use this

[Balinju]

Originally posted by hara
You could use this

i agree, it served to cool 15 computers, you think that it is not enough for 1??

[SparkedFire]

what is that monstrosity?, could you give me more info on phase change and other cooling methods?

[Balinju]

read this thread to see what our project consisted about

Link Here

hint, do not try to build a monster like that for just one computer

[8-Ball]

Originally posted by Alchemy
How surprising to get such an informed post from an Oxford student! (professor?)

Student!

Some of the professors here have this abilty to explain something like that so concisely and with such clarity that it makes you wonder, at the time, what all the fuss is about.

It's only when you get to revising for finals, as I am now, that you discover the notes you took don't have this same magical power.

Once again, where's the head banging the wall smilie.

will have to suffice.

8-ball

[Brent1]

Hello if SparkedFire is just looking to cool with a water chiller then that is great I have played with water chilling and refrigeration witch all of this is my field of work I work for a thermal cooling company here in Canada that we design & install chilling units for all kinds of applications for hospitals and labs. If people wanted the bulky phase changers and just wanted to cool the CPU then that’s good to. I think what SparkedFire is looking to do is cool the CPU not freeze it lol. I will strongly recommend however you have to use the right equipment for pelts you don’t want to spend money and time for nothing. First you need to do your home work on TEC cooling there is a lot of information out there far less confusing than some explanations I have read. For a quick overview of some of the equipment you will need. You have to get the right PSU you need a temp controller, pump rad or rads blocks and to figure out what you are going to use for your chilling unit itself most water blocks used for CPU’s are insufficient and will not do the job as well you may have to design your own and any machine shop can help you out there. As for condensation one way I combated that problem was with putting a hose into another for isolative properties I had taken all the precautions as if I where to install a pelt on the chip itself. My block that had the pelts that made my water chiller was in its own compartment above the comp compartment including my rad and pump for cooling the hot side of the water block. I used a server tower for this project also taking ambient temp into consideration all I did was use a small radiator inside the case with a blower attached to it and the chilled water went through the rad first before the CPU GPU ext... Thus bringing the ambient temperature down inside the case. Also you need to control the chiller separately from the computer meaning you have to be able to turn the chiller on first for a bit to give the chiller a chance to bring the liquid you are chilling to a desirable temp. My suggestions is just do your home work first then go for it if nothing else you will gain knowledge from your willingness to try something new. One finale note done right Water Chillers are a lot more versatile than the rest. As for Over-clocking you can over-clock higher than if you where to just use water cooling.

Regards
Brent