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caliusoptimus

24/7 Sub-Ambient Build

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Posted · Original PosterOP

This has been on my todo list for about 10 years and the project is finally in progress. Basically, I've run out of other things to blow money on :D

I don't have a serious goal or high expectations here. Just building it all for fun!

 

SO. Here is the plan.

 

Phase one:

Water cool CPU and GPU. (done and working)

Find and experiment with a chiller unit. (chiller ordered, mods needed)

Connect and test the system above the dew point.

 

Phase Two:

Build an air tight case so that the internal atmosphere can be dried to minimal humidity.

Test case for static discharge problems and solve any issues.

(optional) upgrade chiller or add second stage for lower temperatures

 

Phase Three:

Explain electricity bill to wife.

 

 

At the moment I have a water cooled setup on my PC that should be sufficient for sub zero temps. I chose all fittings and components so that I won't have any compatibility issues with glycerol, ethylene glycol or propylene glycol. The GPU block and pump/res contain acrylic, and from what I can tell this should be fine with glycol. The fittings contain nickel plated brass. nylon, and Buna N o-rings and the tubing is PE. Subzero temps may cause issues with the acrylic or the PE, but I'll cross that bridge when I come to it.

 

I ordered a chiller today. Link to chiller. Elkay model ECH8. I chose this chiller for several reasons. The internal, insulated, 0.4gal reservoir is the main factor. Another bonus is that it has 1/4" copper lines for input/output rather than plastic hose barbs (see: aquarium chiller). Also, I got a great price! This chiller doesn't provide a BTU or tonnage specification but judging by the FLA and power consumption it looks to be a 1/4hp motor. Comparing to other units a 1/4hp system is usually rated around 2500-3000btu. The chiller comes with a mechanical thermostatic control which will be promptly replaced with a PID controller and SSR.

 

My current PC eats about 700 watts (prime95 avx, plus furmark, with a modest overclock for both) at the wall, with an 80+ bronze PSU. Based on this I estimate the whole system is pumping out about 600w of heat, PSU excluded. I'm pretty much a pleb when it comes to thermodynamics, but from what I can tell, this chiller should at least maintain ambient at full load. If not, I'll put this chiller under my sink and get a bigger one!

 

Anyway, photos and more details as the build continues.

 

 

 


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@caliusoptimus

 

Ok so i've done loads of research and planning for a similar build.

 

here's what i know.

 

That chiller is expensive for what it looks like it is. at only 1/4 hp.

 

You really should find out what refrigerant it uses. if its 134a like alot nowadays, dont expect great subzero results even if it can go that low without bypassing the thermocople control. 134a has a relativly high boiling point for a refrigerant at roughly -26c, as your coolant temps get closer to the refrigerant boiling point, the efficiency of the chiller goes down, so dont expect to ever hit -26c, infact ur likely only ever gong to get down to at most -10c in ideal conditions (very cold air going into the chilelr unit, e.g durign winter).

 

Your case, best situation is to replace the air with an inert dry gas like nitrogen. This is what im going to do. Its cheap and slightly lighter than air so u dont have to get the case completly 100% nitrogen, just put the input nossle at the top fo the case, and exhaust nossle at the bottom and fill it a couple times till u get mostly nitrogen coming out the bottom. Once it settles you should only have a small layer of normal air at the bottom of the case. Design it so the PC components are above this area.

 

As a precaution, still apply some condensation protection to critical areas like aroudn the CPU. Dielectric grease in the socket, conformal coating around it, and some neoprene ontop. Build a Motherboard cover to make it look nice if ur into asthetics, or buy a motherboard that has an 'armor' already.

 

GPU is harder to do as u have very little space to work with between the PCB and waterblock, i sugest a spray on confromal coating and some thin neoprene or similar material.

 

As you go subzero, be extra cautious of O-rings, both fittings and blocks.

 

Acrylic will develop spider cracks around tapped screw holes ..be carefull. Idealy u should use full metal blocks or acetal topped ones.

 

I would sugest trying out glass tubing if u want the clear asthetic, or going copper for safety.

 

Build a large res so your chiller can be set to keep the res chilled all the time, even when the PC is of, this will allow the PC to run with instant chilled liquid. it wil lalso help reduce temperature cycling which can weaken the o-rings and tubing. Additionaly, not going straight from the chiller to the PC will lower the amount of time the chiller is on, as it will have a buffer.

 

Coolant. if your going subzero, consider Mayhems XT-1 Nuke concentrate. they do 5 litre bottles. it can be used down to as low as -50c, u wont get clsoe to that so u can probably run a 30/70 mix of coolant to distilled water for around -15c protection.

 

 

Feel free to ask more, i've done years worth of research into this kind of project. been put on hold atm though due to other life responsibilities.

 

Look forward to seeing how ur build goes :D


CPU:Intel i7 3930k w/OC & EK Supremacy EVO Block | Motherboard: Asus P9x79 Pro  | RAM: G.Skill 4x4 1866 CL9 | GPU: EVGA GTX 780 Classified w/OC & EK Water Block | SoundCard: Asus Xonar D2X - FiiO X3K DAP/DAC for Headphones | Storage: Samsung 850 Pro 1TB SSD + Samsung 850 Evo 256GB SSD | Cooling: XSPC D5 Photon 270 Res & Pump | 2x XSPC AX240 White Rads (Push) + NexXxos Monsta 80x240 Rad (Push/Pull) | PSU: Seasonic Platinum 1000w | Case: Modded CM Storm Stryker | Panasonic 42" Plasma

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Posted · Original PosterOP

Thanks for the input! Yes, the chiller is r134a. I would have preferred a more powerful unit but I had to consider power requirements for both my PC and the chiller. My setup can draw around 1000w as-is (pc, monitors, desk lamp, speakers etc) so I have to be mindful of the 15A breakers in my house. I got a smoking deal on the unit, so if it turns out to be a waste, the chiller will find a perfect new home under my sink next to a RO system.

 

Instead of using an inert gas I plan to use a strong desiccant like calcium chloride to dry the air. That should keep the whole setup fairly simple, and should I spring an air leak the CaCl2 will have a color indicator to show if it needs to be changed.

 

It's gonna take a while to finish building the case for all this so in the mean time I'll do some testing with the chiller and see where I stand.


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Posted · Original PosterOP

Here's the setup I intend to use with the chiller. I'll get it all hooked up and run it above the dew point for a while, until I find the time to build a sealed case.

 

prime x299 deluxe

7820x delid w/ conductonaut

evga 1080ti ftw3

 

I've currently got it stable at 4.9ghz 1.25v all cores, avx at 4.5. Temps range around 75c on prime 26.6. With prime avx 8k fft's the temps are in the low 90s.

GPU is stable at 127% power limit, 100mhz OC and never goes above 60c.

 

With 70f room temp the loop saturates up to around 35c, running furmark (no AA), and prime avx 8k fft's. All fans are on the same linear curve based on the loop temp, min speed at 27c, max speed at 32c.

 

If the chiller can keep the loop temp down around 20c I think 5ghz w/ 4.6avx should be no problem.

20190106_143820.jpg.3e073b00f4ac26149b19f96808369613.jpg

 

I chose 10mm push-to-connect fittings for the entire build. Great fittings, super easy to install and lots of different options for 10mm tubing. I'm surprised that so few people use them, considering the price is about the same as any other G1/4 fitting. I went with 10mm PE tubing, 8mm ID.

20190106_154854.jpg.5f3a719bbde3bd7348e72272421d81c0.jpg

 

Right now the loop is in this order: pump > temp sensor > tee fitting (drain line) > cpu > 120x120 radadiator > gpu > 120x240 radiator > reservoir

 

Once the chiller is ready to go I'll remove the radiators and the pump/res combo from the case. I ordered a dual/series D5 pump mount to increase pressure in the system. The chiller uses 1/4" lines which are a bit small, so the series pumps should ensure a decent flow rate.

 

The chiller loop will be in this order: series D5 pumps > chiller > temp sensor > Y fitting > individual lines to cpu and gpu > both lines converge into a Y fitting > temp sensor > back to pumps

 

The chiller has it's own 0.4gal reservoir so no need to put another in the loop.

 

So close to testing... getting excited! :D


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15 hours ago, caliusoptimus said:

~SNIP~

 

The chiller loop will be in this order: series D5 pumps > chiller > temp sensor > Y fitting > individual lines to cpu and gpu > both lines converge into a Y fitting > temp sensor > back to pumps

 

The chiller has it's own 0.4gal reservoir so no need to put another in the loop.

 

So close to testing... getting excited! :D

Its best to have a res befor the pump to ensure it never runs dry, especialy when filling. As i mentioned in my last post, its a good idea to have a large res anyway, to reduce Chiller on time. While the chiller has its own res, that res is where the chilling occur's and likely doesnt have a bottom port but rather 2 top ports, making primeing the system a PITA if u set the pump after the chiller.

 

My personal project plan, similar to urs . has a dual loop setup so that i can turn of the PC side and keep the chiller side on.

 

Loop 1

 

Large res* > Pump** > Chiller > back to res.

 

Loop 2

 

Large res* > Pump > PC loop > back to res.

 

* the same res

 

**pond pump e.g Eheim 1262 aka Eheim Universal 3400, or Eheim compact 5000)

 

Doing it this way also allows u to run the chiller side pump at the speed sugested for the chillers best operation, they usualy have much higher flow rates specifcations than what is possible inside a PC loop.

 

For example the Hailea HC2000 r-22 2hp chiller  (the chiller I once considered for my project, im now planning on building my own) has a flow rate spec of 3000 to 6000 L/PH . Good luck getting that in a PC loop considering most dont even reach 1 G/PM (~227 L/PH)


CPU:Intel i7 3930k w/OC & EK Supremacy EVO Block | Motherboard: Asus P9x79 Pro  | RAM: G.Skill 4x4 1866 CL9 | GPU: EVGA GTX 780 Classified w/OC & EK Water Block | SoundCard: Asus Xonar D2X - FiiO X3K DAP/DAC for Headphones | Storage: Samsung 850 Pro 1TB SSD + Samsung 850 Evo 256GB SSD | Cooling: XSPC D5 Photon 270 Res & Pump | 2x XSPC AX240 White Rads (Push) + NexXxos Monsta 80x240 Rad (Push/Pull) | PSU: Seasonic Platinum 1000w | Case: Modded CM Storm Stryker | Panasonic 42" Plasma

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Posted · Original PosterOP
3 hours ago, SolarNova said:

Its best to have a res befor the pump to ensure it never runs dry, especialy when filling.

.....

Doing it this way also allows u to run the chiller side pump at the speed sugested for the chillers best operation, they usualy have much higher flow rates specifcations than what is possible inside a PC loop.

My thinking is that pumps produce heat, and I want the cpu and gpu to receive the coldest part of the loop possible. Probably wouldn't make a noticeable difference though, so I'll give it a try both ways and see what works best.

 

The "minimum flow rate" problem only applies to chillers with a certain type of evaporator. The chiller I have chosen has the evaporator and temp sensor directly inside the reservoir, allowing it to run properly with zero flow. If you do a deep dive I'm sure you could find one like this in the 2hp range.


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Why not skip the water altogether and make the copper blocks part of the refrigerant loop?


Asus Sabertooth X58, Xeon X5680 @4.0Ghz, NZXT Kraken x61, 24Gb Klevv 1600mhz, MSI GTX 1080 Armor,

Seasonic SSR-550rm, Toshiba 1TB HDD, Silicon Power 120Gb SSD, Rosewill Stryker M

 

Dell Optiplex 790, i7-2600, 16GB, Gigabyte Windforce GTX 960 4GB OC, Corsair CX550M 

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31 minutes ago, asand1 said:

Why not skip the water altogether and make the copper blocks part of the refrigerant loop?

Your then looking at a pure phase change system which uses a different set of hardware, also at that point going single stage is a waste and you would likely just go fully into a 2 stage or higher system that can go down around -100c.

That kind of system isnt really usable 24/7, but rather a bechmark system akin to a Ln2 /DICE potted system.


CPU:Intel i7 3930k w/OC & EK Supremacy EVO Block | Motherboard: Asus P9x79 Pro  | RAM: G.Skill 4x4 1866 CL9 | GPU: EVGA GTX 780 Classified w/OC & EK Water Block | SoundCard: Asus Xonar D2X - FiiO X3K DAP/DAC for Headphones | Storage: Samsung 850 Pro 1TB SSD + Samsung 850 Evo 256GB SSD | Cooling: XSPC D5 Photon 270 Res & Pump | 2x XSPC AX240 White Rads (Push) + NexXxos Monsta 80x240 Rad (Push/Pull) | PSU: Seasonic Platinum 1000w | Case: Modded CM Storm Stryker | Panasonic 42" Plasma

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Posted · Original PosterOP

Got it hooked up and running! So far working great.

 

The maximum load I can get on the computer is running prime95 avx 8k FFTs and furmark (no AA) at the same time. This pulls about 700w at the wall with an 80+ bronze psu. The chiller was able to maintain 12c at full load, so that's good news. I didn't set it any lower as the dew point here is 10c at the moment.

 

With a more realistic load this chiller should be able to pull much colder temps!

20190109_165914.jpg.05795cb1cb6165e89e0284ea4d2f6608.jpg

20190109_165857.jpg.c73ba1507aee8587c4093c6904d59925.jpg

 

 

The system was a pain to prime, I definitely need to add a reservoir to help capture the air bubbles.

 

The chiller is also noisier than I had hoped. The sheet metal enclosure amplifies the vibration from the compressor and the fan. The fat is also quite large and noisy, considering the small amount of air flowing over the condenser. I will probably repurpose my ml120 rad fans to go on the condenser. I'm also thinking about adding some foam to the inside of the enclosure to damp the vibration.

 

Here's a run with prime26.6. Temps for prime avx maxed out at 75c. Before the chiller these temps were about 15c higher.

 

p26.thumb.jpg.b73092c4285319a623ec47d0e879ff7f.jpg

 

To be continued...


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Looks good, will be interested to see howwell it holds colder temperatures, especialy subzero.

 

Buy some 1mm , or the thinest u can get, sound dampening sheets and dissasemble the metal case. Reassemble with the foam sandwiged between all the joins, this will stop vibration between each joint. Normal thickness sheets on the inner walls will help reduce noise even more so. Also looks like you could unmount the compressor and remount it on some foam pads if u so choose.

 

Replacing the fans is a good idea but ensure your not acutauly downgrading, i doubt it will be noted on the fan itself but check to see if it has the CFM and pressure specs on it. It looks to be a pritty beafy thick fan, so replacing it with ML120 fans will likely be a downgrade. maybe consider just adding those fans as intake fans to aid the original fan.

 

Consider a igloo, or similar brand, cooler box (Those boxes used for keeping your beers cold, and for picnics), for the res. They are pre insulated and come in various sizes from , i think, 5 litres to over 25 litres , and can be easily modded for use as a chilled reservoir.


CPU:Intel i7 3930k w/OC & EK Supremacy EVO Block | Motherboard: Asus P9x79 Pro  | RAM: G.Skill 4x4 1866 CL9 | GPU: EVGA GTX 780 Classified w/OC & EK Water Block | SoundCard: Asus Xonar D2X - FiiO X3K DAP/DAC for Headphones | Storage: Samsung 850 Pro 1TB SSD + Samsung 850 Evo 256GB SSD | Cooling: XSPC D5 Photon 270 Res & Pump | 2x XSPC AX240 White Rads (Push) + NexXxos Monsta 80x240 Rad (Push/Pull) | PSU: Seasonic Platinum 1000w | Case: Modded CM Storm Stryker | Panasonic 42" Plasma

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Posted · Original PosterOP
On 1/10/2019 at 9:07 AM, SolarNova said:

....Buy some 1mm , or the thinest u can get, sound dampening sheets and dissasemble the metal case. Reassemble with the foam sandwiged between all the joins, this will stop vibration between each joint. Normal thickness sheets on the inner walls will help reduce noise even more so. Also looks like you could unmount the compressor and remount it on some foam pads if u so choose....

I picked up some thin foam strips to wedge between the joints. Definitely helped, unfortunately the fan is still quite out of balance and is causing 75% of the noise. I'll get around to trying some different fans once I have time to make a duct.

 

 

On another note, I think 5.1... even 5.2 is within the realm of possibility without pushing below the dew point.

 

Prime 26.6

 

p26.jpg.8cd90efdfe63d4a68b50b62d43b0b4ca.jpg

 

Prime 29.4 (AVX)

 

p27.jpg.5a2f3a088453db78632548c31c2b0bf2.jpg

 

 


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