Question CPU Cooling using Peltiers with a water loop

[jacksoncarl256]

Peltier cooling water loop
Unsatisfied with you tube vids of just adding a Peltier cooler to the CPU and running at minus temperatures, since I worked in electronics I built a temp sensor connected to a meter to monitor temperatures. The temp voltage also controls a transistor stage to control the voltage to the Peltier. At this time I'm thinking of using water cooling to cool the Peltier hot side, the cold side is used to cool water that is circulated to a water block for the CPU. A big thing is insulation and I have a lot of rapidly moving air inside the case, Hopefully I can get some fairly cool water In a plastic container that will be able to cool the CPU and vent the heat to a radiator. I still have to make a case to hold the water and test the whole system out. I disliked the size of the temp sensor of commercially selling temp controllers and I'm using analog rather than digital on off control. Also it is fairly easy to insulate the Peltier so it is in a sealed chamber and eliminates the condensation issue.

 

[jacksoncarl256]

I was able to find this thread again, I work on this project about every day, I already have the majority of components needed to set up the two water loops, one for cooling the CPU with chilled water and another to remove heat from the hot side of the Peltier. A special water tank was set up in which to cool the water in it, plastic sides and top with a copper bottom, fins to help cooling. I use a method of providing a sealed area with cooper plates and foam insulation on the sides to prevent condensation. The water temp is monitored with a circuit I built using IC's and gives a read out and the voltage also controls two hi current transistors to keep the water from freezing. I have a feeling I'll learn as I go along.

 

[evan1715]

i wanted to do something similar but it's an idea in my head as a hypothesis rather than based on anything.
i figured what if i got a big enough peltier plate, or two, put it on the radiator or in the water to make the radiator cold, then it would circulate the colder water to the cpu. then attach massive air heatsinks to the hot side of the peltier plate(s). it would be a huge and ugly look and i'm unsure if it would even work well enough. so let me know what you figure out with your results

 

[jacksoncarl256]

I don't think trying to cool a radiator would work, the peltier is 40 mm by 40 mm and you need to get that surface area to a flat surface. Maybe a water block to cool the water going into the radiator but the radiator will heat the water up to room temp. Other considerations are to keep the water from freezing and to provide a sealed place for the Peltier so there is no condensation.
So I have 3 40x 40 Peltiers and can use 2 with my system the tank is made for 1 Peltier but I could also use 1 with a water block. Right now I am repairing a leak, I use a theaded rod to go into and out of the tank and 1 leaks, best solution is to solder but the threaded rod can not be soldered. I'm using silicon for a seal.
I wish you luck with your ideas, I go through a lot of threads here to get ideas.
Go with cooper as much as you can, it transfers heat at twice the rate as aluminum. Water transfers heat much better than air and air is dependent on the humidity. Both the radiator and heatsink will try to make things go to the air temp. The hot side of the Peltier has to be cooled and this is additional heat that has to be dissipated.

 

[n0ns3ns3]

nothing new/original... it's been done so many times before ...
there is always same issues that make it fun experiment and impractical for every day use.

 

[jacksoncarl256]

I'm updating the system now, I'm working on the second water loop going to the radiator. It is going to first have 1 then 2 water blocks then the radiator, this removes heat from the hot side Peltier. The air heat sink with fan will not be used so I'm converting the water tank so the hot side of the Peltier is connected to a water block. I'll have to make 4 plastic pieces glued to the sides of the plastic tank so I can connect the Peltier to the tank and the hot side connects to a water block.

 

[jacksoncarl256]

I lost the use of my tank, the cooper plate moved upward breaking a silicon seal so it leaked. I'm fixing it now with better ideas about how to avoid this in the future. I still need another tank for the radiator and I'm hoping to use a plastic bottle. Tanks are expensive and I've already put enough money into this system, probably good tanks that would do the job quick and easy.

 

[jacksoncarl256]

The plastic bottle seemed to work and I'm making another of the same thing to go where the tank had been. I'll pass the water through a water block cool side and use a water block on the hot side going to a radiator. This should give me time to get the tank fixed up right rather than having to rush through it.

 

[jacksoncarl256]

Things are moving along pretty well, I have 2 plastic bottles to serve as tanks, and I was able to make another sealed Peltier, I'm using plastic to hold the Peltier, a water block on either side, four screws hold everything together. I'll have to take the thing apart to put on thermal paste on the Peltier and water blocks. I also want to put a piece of tubing on the copper plate to measure the temps of the hot and cold sides, I should put in something to measure water temp. The water block cooled water will be used as a pre cooler for the original tank I'm repairing. I should be able to get this thing going today or tomorrow.

 

[jacksoncarl256]

I'm remaking the cooper piece that serves as the bottom, I had a bit of spare time because I'm waiting for cooper elbows I ordered to arrive. Going along pretty well on the tank, putting in plenty of cooper fins to help cool the water. The elbows arrived yesterday so I'll probably split time between the elbows and the cooper bottom tank. I'll probably
read some of the posts here maybe someone has a useful Idea I could use.

 

[Carl2]

Still working on this project, since the plastic tanks were not strong enough I've replaced them with copper tanks, I think putting on the tight fitting plastic tubing put to much stress on the plastic tank. I have I tank that holds 1 cup of water, another pre cooler tank that holds 1/4 cup of water cooled with two peltiers 12709. I tested the current draw of the peltier and it draws 3.4 A, the last digit indicates the max current the peltier can draw without harming it. I found the new peltiers I ordered 12715 can draw 9A which should make the time it takes to lower the temp shorter. It took the original version 20 min to go from room temp to 40 F, smaller tanks would have also increased the cool down time but the cooper tank is already built and I have no idea what size is really needed.
There was a low temp rise when cooling the hot side of the peltier and it will be interesting to see how the radiator does with the new peltiers.
Right now I'm redoing the temp monitor, it uses a very small sensor which is really what you want to get temp measurements, it is non liner but what is available, I tried the infrared thermometer but they have their limitations.

 

[Carl2]

I spent a bit of time doing autobody work on an electric Leaf and have just gotten back to work on the Peltiers. I've begun making my own 90 degree elbows with brass tubing because they take less space. I'd used a tin can as a tank but noticed rust coming from it and an in the process of replacing it with a copper tank. All the tanks are now copper and I have more powerful Peltiers to get the water cooler faster.

 

[4Ryan6]

https://www.overclock.net/forum/62-peltiers-tec/1633988-chilled-water-cooling-vs-3-0-build-log.html

If you really want to have a fully operational peltier cooling system this is how to do it using heat pipe air coolers to cool the hot side of the peltier. Ry

 

[Carl2]

When I was trying out the Peltiers I did use air cooling for the hot side, it worked pretty well but was pretty large. For me I'm thinking a cooper water cooler will work well, it seemed to handle the lower power Peltiers pretty well and allows me to run tubing where a heat sink now is . At this time I will say keep a minimum amount of water in the system to allow a quicker cool time for the water. The system I now have uses a water cooled GPU and doesn't even use tanks at all, just the radiator and tubing. I took a look at the link provided, it seems to be useful info, at this time I can't even remember what my CPU number is I just go with a 6 core.
The 2 Peltiers I'm using each use 8 amps at 12 volts. Cleaning the table to set up the water loops again and see what the cool down time is.

 

[Carl2]

I was able to find this again, the Peltier is actually a 9 A, using the 9 A Peltier is a bit of a problem and I'm not sure why. The 6 A Peltier I was using brought the water temp down to the low 40's F in 20 minutes but switching to the 9 A Peltier is a problem. I took another 9 A Peltier and put it on a air cooler, by itself the Peltier went into the minus F very quickly, it was able to cool down a unconnected water block and freeze water I put on it quickly. Putting a connected water block in a water loop caused problems again with a low reading in the mid 50's.

 

[Carl2]

This kind of reminds me of the Leds which I'd used in the lab in the 70's, it took 40 or 50 years until they were used for home lighting and automotive lighting. I think the Peltiers have the potential but it will take many years before it will be really useful.
Condensation seems to still be a problem for some people but I have been using a layered approach and have not had any condensation problems. I've played with a silicon method where I use a layer of silicon for insulation the same thickness as the Peltier, this removes the cooper and the foam I had been using.
I have a square shaped tubing I wrapped around 2 3/4 inch pieces of wood this gives me the same size as the Peltier which it will sit on top of. It still needs a top, bottom and cooper heat spreaders to aid cooling the water, this will hold a 1/4 cup of water. I'm not satisfied with the cooper water blocks sold since they only hold a table spoon of water, I'll probably begin making my own water blocks.