Mineral Oil Cooling Question

[DuroMentis]

Hello all,

I just got my brother's old PC and I am free to do with it as I may (mwahahaha), but seriously, I've been really looking in to submerged PC builds, I've grown rather fond to the idea of it. The question in my mind is, how would one keep the mineral oil cool? Its not like you can just run the mineral oil through a standard liquid cooling setup, it'll eat through the tubes probably everything else. I have an idea but its complicating and I don't think I'd be able to achieve it without the correct tools *which I do not have*. Anyways the idea is cut the bottom out of an old aquarium and replace it with a copper box that matches the design of the aquarium, the copper box must be sealed completely as well as sealed to the aquarium with no holes for the mineral oil to leak in to the box. By the way I figured copper would be best because its highly conductive, or so I've heard. Then, I would cut holes allowing a liquid coolant to fill up the copper box and run that coolant through a pump to the radiator. The coolant would cool the copper which would cool the oil. I'll probably do a Sketchup in a second to explain this better. But while I do that, does anyone think this would work? I'm not saying I'm going to do it, but I was just very curious. Also, does any one know of another method? Mine sounds complicating, so I'm sure there must be a better way. Any ideas?

[Bopher]

As far as I understand the idea behind the submerged pc. You don't need the oil to be run through rads and such. the movement of hot oil to cooler areas is what moves the heat away from the components. using fans help in moving the oil around a little fast. But thats how I understand the idea. I could be wrong.

[Trace]

Bopher has it right- Convection currents cause the less dense hot oil to the surface where it loses it's heat to the air, cools, becomes denser, and then sinks back to the bottom.

Check out this link: http://www.pugetsystems.com/submerged.php

[mDust]

Actually, Puget Systems recommends cooling your oil. Their second build was actively cooled. Their submerged system has been running fine for 2+ years, although it originally ran hot. To work, the oil must be kept clean and free of dust/debris...aka a closed system. Closed systems trap heat, so the oil should be cooled unless you're fine with everything getting 80+C hot after 6-8 hours.
And no, mineral oil does NOT dissolve acrylic, PVC or polyurethane, so normal tubing, a strong pump and a radiator will work fine. Click my sig for details on my submerged design.

Cooling the oil from the bottom would work eventually, but not well. The components heat the oil and causes it to rise to the top of the tank (convection). This means the oil you should be cooling is at the top, and you'd be cooling the coolest oil. Eventually, the temperature difference would cool the rest of the oil...but this is very inefficient. If you still want to use a heat exchange idea instead of pumping oil, simply put two rads in a WCing loop. The first rad should be submerged in the oil near the top and will heat up and transfer the heat to the water. The second rad should be cooled with fans thereby transferring the heat out of the closed system. It will work, but probably not as well as pumping the oil itself.

[Oneslowz28]

I agree. Just run the oil through a normal Pump to radiator loop. Use a fan or two to move the oil around the enclosure to prevent hot spots and all will be fine.

[DuroMentis]

Alright thanks everyone, like I said though, I was just curious hehe. I doubt I have the courage to submerge my PC. I was actually looking in to the OCZ Phase changer, seems more reasonable for me to get that instead. And Probably cheaper too. I have a Nano aquarium that I was thinking of using for the submerged build, but its like 20 gallons or so, I don't know (By the way I'm sick so I might not make sense heh). So that'd be a lot of Mineral Oil. That and my folks said they were going to fill the Nano aquarium with fresh water fish, so that basically told me I won't be able to do it. Phase changing on the other hand is a possibility, at least I think it would be. On www.frozencpu.com the OCZ Phase Changer runs for around 379$ and with the temps it displays, seems very worth it. My only complaint is the case on it. Anyone know how hard it would be to make an internal Phase changer? And is there any risk in that? Getting one to fit in the case is not a problem for me, I just wasn't sure if it would be a bad idea or not, I saw a case awhile back with a built in one, it was ugly as sin though and cost a grand, which as a 17 year old, is not in my budget (or lack there of). Any thoughts and ideas?

[x88x]

I've never really looked into phase-change, so I can't really comment on making one..however, I can pretty much guarantee that it's not gonna get you the best bag for your buck, which I would expect is likely what you're looking for? TBH that would probably be a nice air-cooling system. ...more exotic systems are just so much more fun though

@mDust: That's a really good idea! Use the top rad as a heat absorber..I was thinking of something along those lines with a mesh of tubing in the top of the tank, but this would work much better, plus be a lot easier to implement.

[mDust]

Anyone know how hard it would be to make an internal Phase changer? And is there any risk in that?

To build it from scratch? Very hard and potentially dangerous. If you want to go the phase-change route, then I'd highly recommend buying an off the shelf product and then modding it to fit in your case. You should also do a ton of research on the subject because they are high maintenance systems and are finicky if they are not setup perfectly. Also, you'll have to keep shuttling the system back and forth to an HVAC specialist to have it charged or vented as the refrigerant is dangerous and depletes the ozone layer. It's against the law in several countries to vent the gas into the atmosphere. These things prevented me from buying a phase-change unit several years ago. I just didn't want to deal with it all, but if you want frosty temps, then this is about the only way to get them.

@mDust: That's a really good idea! Use the top rad as a heat absorber..I was thinking of something along those lines with a mesh of tubing in the top of the tank, but this would work much better, plus be a lot easier to implement.

I'm glad I could help simplify things.

[DuroMentis]

mDust, yeah I didn't mean building one from scratch, I don't have the license or the desire to get one. I always wondered what the catch was with Phase Change systems. I didn't know they were so high maintenance. But as for the ozone layer problem, I doubt it's a worse problem then the amount of hairspray most women use daily. And I mean that in all seriousness. Fun fact, right? That said, women really will be the death of us. XD