Cooling Dual Stage Cooling. Water + Peltier on Air

well, PC reliability has always trump performance for me.

but yesterday, i came across a brand new unit of Coolermaster Aquagate at a retail outlet i hangout. i couldn't resist and got it for $65 with everything in a big box. a bargain i think.

with a couple peltiers and a waterblock sitting somewhere, i got an idea and want to run through folks with more experience working on water cooling. here's my idea:

Boosting Water Cooling

I intend to connect the Aquagate in a standard manner, but will hook up a second waterblock along the pipe with water flowing into the primary CPU water block.

The flat surface of the secondary water block will contact with the cold side of the 18A (max) peltier device, and the hot side is connected to a redundant CPU heat sink on air, probably sticking outside the case.

Peltier is probably going to be supported by a reasonable secondary PSU (single rail) to avoid bringing the whole +12v rail on the main PSU down.

Are there any flaws that i haven't think of or you think is a problem? thanks.

 

The peltier would have to be before the cpu block, but after the aquagate - if the peltier is cooling the water down to _lower_ than ambient air temp, then the aquagate would actually be warming the air....

 

if you manage to get the water cooler than the air temp you can get condensation. watch out for that.

 

yeah, condensation...

i have to plug everything in and check temp difference with & without a peltier. simulate the CPU with a variable temp hot iron

might cut a slit at the pipe close to the IN of the CPU block to place a tiny temp probe, just to know how cold the water is going into the CPU block.

Getting the most reliable seal is still a bit of a question.

so, hot water from CPU goes into Aquagate (1st) and then the Peltier (2nd) then back to CPU.

will likely place the Aquagate internally for simplicity and the peltier outside, if not lowest part CMSTACKER case.

thanks

 

Have to make sure the heatsink can take enough heat away, if not, the whole thing will just dump heat into the loop.

Rwd

 

Hmm... that's interesting - first of all, the heatsink on the peltier would have to be able to remove however many watts the pelt makes in addition to heat from the loop, so depending on what's in it that could be a problem. I think it might just be better if you used the pelt like people usually do - cold side down in between the CPU and block, with plenty of insulation.

The reason why most people running pelts on their CPUs and stuff use water is because most heatsinks aren't good enough for the 100W CPU in addition to the 437W pelts they use on the CPU. I guess that also depends on how big your pelt is, but think about this too - the Monsoon II and ChillTEC are both air coolers with pelts and perform worse than the Ultra-120 eXtreme.

 

Oh, your thoughts are MUCH appreciated.

I think it will probably work by powering the Peltier on the 5V instead of 12V.

The reason i did not subscribe to the Peltier on CPU design is lack of fault tolerance.

By having the Peltier cooling the liquid a bit more before the CPU, a failure won't kill the CPU (unlikely because BIOS CPU shutdown temp)... but more importantly, the system will continue to operate if i leave some temp margin after OCing.

 

I guess the big question that needs to be asked is What is the reason for the pelt cooling? If it's just to have a fun project that works okay then you'll be fine. However, if you're looking to significantly cool the water and get better overclocking results this setup probably isn't going to do the trick. You mentioned you have an 18A peltier; it's going to be drawing ~90 watts at 5V. I think you'll find most computer power supplies won't be able to handle that kind of draw on the 5V rail. I hope this doesn't sound too critical, just some points to keep in mind when designing this. There aren't very many people running pelt systems anymore; I think most have found for the same cost they might as well go chilled water phase or direct chip phase change.

 

glad to flush some ideas with you guys. i should drop the chicken shlt stuff. CPU over heat cut off should be ok.

i'll go borrow a lab bench from someone and use their lab power supply, then i would know the how much current some peltiers would draw and what i need on a secondary PSU. i saw bunch of peltiers and stuff sitting in boxes somewhere. i am sure i can find peltiers that can be air cooled on 5v and some AMD X2 6000+ heatsink-fan some where.

1 peltier doesn't seem to make much sense after all your inputs. might try two or a series outside the CMSTACKER. there are bunch of freebies sitting in rooms where i am can toy with. a CNC and wire-cutting machine shop would come in handy.

chilled water phase or direct chip phase change are interesting, but there are no freebies here. I'm just curious what i put togeether on a budget.

by all means be critical as much as possible. i am counting on folks to clobber me for flakey ideas. removing ignorance from my 1sft of intelligence is a boon. no ego attached here

 

Freebies certainly help If you can get a couple of pelts in a line at a voltage that can easily be cooled by a heatsink I'm sure you'll be able to achieve good results. Hopefully electricity is cheap in your area though . One last thing to consider, if you're aiming for subambient temperatures then you need insulate your cpu area on the motherboard so condensation doesn't form and short anything out.

 

ok first unless the water is just above freezing u wont get condensation on the cpu but u will get condensation on the blok with the tec so plan for that make sure the cooler can handle the hot side other wise its pointless also the tec doesnt need to cool the water/coolant by that much even if u get it bak to room temp is great b/c thats still much cooler than ur cpu