Question CPU Cooling with Peltiers in a Liquid Cooling Loop?

[ThatOneDude_21]

I'm planning to do a liquid cooled loop with the coolant going from the CPU block to a 120 mm radiator, to some Peltiers to chill the liquid below ambient temps. I'm doing it for a school project and I dont have much funding.

Tbh I have no idea what i'm doing and could really use some advice. What Peltiers should I use? Whats the best way to transfer cold from Peltier to water? (I have access to a CNC if needed) How should I cool the hot sides of the Peltier? Is it a good idea to have the radiator in the loop?

Im cooling an i5-8600k and nothing else. I have only an NZXT H500i case but am willing to mod.

Any help or advice is greatly appreciated, thanks!

 

[kanewolf]

The problem with below ambient cooling on a CPU is condensation. Your coolant lines and maybe the CPU block will be condensation points.

Have you read this thread on peltier cooling -- View: https://www.reddit.com/r/hardware/comments/206tui/why_arent_peltier_cpugpu_coolers_more_popular/

 

[ThatOneDude_21]

The problem with below ambient cooling on a CPU is condensation. Your coolant lines and maybe the CPU block will be condensation points.

Have you read this thread on peltier cooling -- View: https://www.reddit.com/r/hardware/comments/206tui/why_arent_peltier_cpugpu_coolers_more_popular/

Hey, thanks for the reply

I used an online calculator: http://www.dpcalc.org/ and it says the dew point in my house should be around 13C, so in theory, if I keep all the temps above 13C, I shouldn't get condensation issues right?

 

[Carl2]

Tp avoid condensation I use a layered approach that I read about and tried. A layer of cooper sheet, a layer of foam a bit larger than the Peltier and another layer of copper. This pretty much insulates the Peltier and I've never had condensation. For starters I'd use the 6 amp Peltiers I've been able to get to the low 40's F with them and took 20 minutes to get there. I just switched to a 9 amp Peltier, by itself it will get to minus degrees F very quickly.
The set up I am working with uses two pumps, one to bring water to a radiator from the hot side and another pump to supply water from the cool side to the CPU water block. Air coolers are nice but take up a lot of space. You Tube has a lot of vids with useful info.

 

[gggplaya]

Perhaps you should use a heat exchanger instead of a radiator. Then put a temperature sensor directly on the output of the heat exchanger(PC side) to ensure it does not go below 15c with your closed loop control.

You can control the fluid pump or peltier amperage, or a combination of both, but any condensation will happen external to your PC as long as you ensure the coolant coming out of the heat exchanger doesn't go below 15c.

Koolance heat exchanger: https://koolance.com/hxp-135-compact-plate-heat-exchanger

I've thought about doing this with geothermal instead of peltier. It would require digging into my soil behind my house about 6 feet deep. Laying some heat exchanging hoses to a heat exchanger in my basement. Then a small pump to move the fluid to my computer. The pumps would be the biggest energy consumer, but the cooling would be free and below ambient.

 

[Carl2]

I had worked in electronics and had made a transistorized controller that can be used to control the current going to the Peltier by using a pin head sized thermistor. It seems the simplest and most direct way to cool the CPU is to have the Peltier directly on the CPU.
Condensation can be eliminated by using the layered or insulating method. A small size thermistor is important to remove lag in temperature control.
In the mean time I am using the 2 water loops, 1 for the radiator for hot side heat removal and 1 for the CPU cooling using a water block. I had found the Peltier response time is very quick and can cool down to the minus degrees F in very little time. I'm finding some very high prices for water cooling and some things like the water block only holding less than I table spoon of water and temp sensors to large with a long lag time are annoying .