Mineral Oil questions

[RomeoReject]

Hello everyone, I'm looking for answers from those who have experience with submersion cooling. I'm aware of the pros, and more importantly, the cons of such a setup. I had a few questions I was hoping to get some advice on. I have an HTPC built up using super low-end hand-me-down components (I'll post specs at the bottom), and it will be used exclusively for media stuff, as I have my own PC for gaming. I already have a fish tank for it, it's a 12.6 gallon tank, which will be filled fairly close to the brim (12 gallons).

1) The biggest question is of cooling. I was planning on welding up an aluminum sheet in a boxed shape (16" by 40" of .050" aluminum) for the "lid" so dust/water doesn't get in, but I was wondering if welding on fins that would dip in to the oil would provide sufficient cooling. If not, would a pair of 200mm fans (One pulling up, the other pushing down) moving oil past those fins provide enough cooling? I want absolute silence from the unit, so radiators or exterior fans are a no-go.

2) I've read others saying the oil changing temperature will want it to expand or contract quite a bit (Enough to shatter the glass). Given that I want to seal this completely from the outside, this is a concern. As the only thing holding the "lid" section on will be its own weight, an increase in pressure should be able to push it up off the seal. For solving a vacuum, would a one-way check valve behind a filter allow too much condensation? Should I seek out a different solution? Am I overthinking this issue anyways?

3) The last issue I've read is that oil tends to wick up the cords and leak out. I want to lay my motherboard flat anyways, I'll use extensions for the various cords (USB, power, 3.5mm audio and HDMI) with cutouts on the lid for the ends. I will then seal the metal around them completely. Will this prevent the siphoning effect some people seem to encounter? Should I be looking for a different solution?

The mineral oil aspect is very set-in-stone, so please don't worry about warning me about the various concerns (Upgrading, weight, overclocking potential). None of them are an issue to me. I appreciate any help others can provide, preferably those who have experience with submersion cooling. Thanks!

Specs:
Processor: AMD Athlon 64 X2 3800 90W (An ancient one with the stock heatsink)
RAM: 4 sticks of 1GB DDR2 at 1600MHz (Unknown brand, also ancient)
MB: Some old MSI board (Don't have much to go on with this, was ripped out of an old family computer. Was the board attached to the processor and RAM)
GPU: Zotac GT 240 1GB
PSU: Old Antec 520W

 

[photonboy]

I think attempting to completely seal this thing up is problematic.

Since you are committed to this, I suggest you first do an immersion, fish-tank approach and get the kinks worked out there before attempting anything more complicated.

 

[USAFRet]

Completely 100% sealed?
What will you do with the hard drive(s)?

The wicking you hear of is on the inside of the peripheral cables.
Come downstairs one morning to find your mouse has peed mineral oil all over your desk.

 

[USAFRet]

At some point, you must remove the heat from the oil. Otherwise, you'll simply have a tank full of 70C mineral oil.
Not sure if your alu fin concept is going to be enough. There needs to be some heat transference to the outside room.

 

[RomeoReject]

I think attempting to completely seal this thing up is problematic.

Since you are committed to this, I suggest you first do an immersion, fish-tank approach and get the kinks worked out there before attempting anything more complicated.

From what I'd read, without sealing the oil rapidly becomes contaminated, which can lead to shorts.

Completely 100% sealed?
What will you do with the hard drive(s)?

The wicking you hear of is on the inside of the peripheral cables.
Come downstairs one morning to find your mouse has peed mineral oil all over your desk.

Oh, completely forgot to post the drive in the specs. It's an SSD, so it'll be in the oil with everything else. I have a NAS for larger media storage.

Do you think that by "separating" the components with extensions, it might stop the siphon effect?

At some point, you must remove the heat from the oil. Otherwise, you'll simply have a tank full of 70C mineral oil.
Not sure if your alu fin concept is going to be enough. There needs to be some heat transference to the outside room.

Alrighty, that's fair. I was hoping that the aluminum would soak enough heat from the oil and radiate it to the ambient air. It was Tom's oil PC that I was hoping to emulate (It had no fans, outside or in). I might need to underclock/undervolt.

 

[USAFRet]

Even with an extension cable....one end will be in the oil, one end out.
The out end will eventually pee oil out.

Your fin concept merely transfers some/most of the heat to a 640 sq in flat alu plate. Which is much smaller surface area than a typical liquid cooler radiator, that is also cooled with fans blowing through it.

The system generates the same heat. A standard air or liquid cooler uses the entire room air volume as a heat sink.
Cool air coming in, warm air blowing out.
A fish tank full of oil reduces that 'volume' to that of the fish tank.

Are you putting some sort of fin arrangement directly on the CPU, to draw the heat out of the CPU? Or just relying on the oil?
Have you addressed the microbubbles and hotspots under the CPU?

 

[RomeoReject]

Even with an extension cable....one end will be in the oil, one end out.
The out end will eventually pee oil out.

Ah, OK. So are there no solutions to that issue then?

Your fin concept merely transfers some/most of the heat to a 640 sq in flat alu plate. Which is much smaller surface area than a typical liquid cooler radiator, that is also cooled with fans blowing through it.

I can appreciate that, though I'm wondering how TH pulled it off with an overclocked PC with less oil. I realize mine isn't going to be running on ice or anything, but I would still expect heatsick + more oil - wattage would equal out to less temperature, not more, wouldn't it? Plus there are fanless PCs these days with more potent components than my own that seem to do alright.

I don't mean to be argumentative, I just want to make sure I'm not looking at something that may not even be an issue.

The system generates the same heat. A standard air or liquid cooler uses the entire room air volume as a heat sink.
Cool air coming in, warm air blowing out.
A fish tank full of oil reduces that 'volume' to that of the fish tank.

Fair enough, but the tank itself is also trying to equalize its temperature with the air around it. That's how Tom's Hardware cooled their one back in the day: http://www.tomshardware.com/reviews/strip-fans,1203.html

Are you putting some sort of fin arrangement directly on the CPU, to draw the heat out of the CPU? Or just relying on the oil?

CPU will use its original, ugly heatsink, along with the CPU fan to keep oil moving over it.

Have you addressed the microbubbles and hotspots under the CPU?

Well I did hear of one member suffering that issue, everyone else has said it hasn't been an issue, in the build threads I've read. If it becomes an issue, I can use my silicone to seal off the CPU. Not expecting that to be an issue though.

 

[USAFRet]

Components that were designed to be fanless, sure.
But again, you are just heating up a tank of oil. It does not have any magical properties, except for heating up slower. And also cooling off slower.

You have no real heat sink except for the surface area of the tank and the lid.

But....
Build it.
Document it.
Show how it's done, both pro and con.

Maybe you've discovered the magic formula.

 

[mjslakeridge]

Are you sure the stock cpu cooler fan will spin, given the resistance of the mineral oil is likely to be greater than air? Is it even necessary to have the cpu cooler installed for this setup? Perhaps you could design something to stir the oil throughout the enclosure at a higher rate. I don't have answers, just found this thread interesting and thought I would ask the questions.

 

[RomeoReject]

Components that were designed to be fanless, sure.
But again, you are just heating up a tank of oil. It does not have any magical properties, except for heating up slower. And also cooling off slower.

You have no real heat sink except for the surface area of the tank and the lid.

But....
Build it.
Document it.
Show how it's done, both pro and con.

Maybe you've discovered the magic formula.

Why do I get the feeling you're waiting for my build to be a warning message to others? :lol:

Are you sure the stock cpu cooler fan will spin, given the resistance of the mineral oil is likely to be greater than air? Is it even necessary to have the cpu cooler installed for this setup? Perhaps you could design something to stir the oil throughout the enclosure at a higher rate. I don't have answers, just found this thread interesting and thought I would ask the questions.

They do spin, but they spin extremely slow in comparison (100-200RPM). Doesn't seem to ever burn them out according to Puget Systems, despite the added strain.

As for the CPU fan, it's likely not doing much in the way of flow, but it does help agitate the oil, which prevents hotspots.


Anyways, it'll still be a few days before I can set it all up anyways. I can't pick up the aluminum until this weekend (The metal dealer closes before my work does), but I'll document things, and point out exactly what went wrong before my fishtank explodes.

 

[mjslakeridge]

Good luck! I will be interested to see how this works out for you. Hopefully you don't have any kids that play baseball or golf inside the house. 12 gallons of mineral oil on the floor would be quite a mess.

 

[USAFRet]

I'm not looking for 'a warning to others'.

Just that whenever anyone proposes some weird construct, I almost ALWAYS ask for a build log, and a truthful Good/Bad report.

It it works, great!
If it doesn't, we know what not to do. This is the way of design.
Build, fail, reconfigure, build, fail, reconfigure, SUCCESS! Or not success, because we were going down a dead end.


If it keeps the same temp, but absolutely silent, that is a success.
If it heats up too much but still silent, that is probably a fail.
If it pees mineral oil all over the floor, that is a different kind of fail.
etc, etc...

 

[Outlander_04]

One of the things that has impressed me most about the oil immersion plan is that if it was worth doing it would be done more often.

I salute your spirit of adventure

The cooling issue .... what is the surface area of the fins of a stock cooler? How does that compare to the external surface area of the fish tank?
I do not think you can immerse a hard drive. They are vented [ with the exception of some helium filled models] and oil getting in will surely ruin the drive

 

[RomeoReject]

Good luck! I will be interested to see how this works out for you. Hopefully you don't have any kids that play baseball or golf inside the house. 12 gallons of mineral oil on the floor would be quite a mess.

Ain't no kids at all, so if it all goes to hell in a handbasket, I'll have no one to blame but me or my Mrs. And given that blaming the Mrs is tantamount to suicide, that just leaves me.

I'm not looking for 'a warning to others'.

Just that whenever anyone proposes some weird construct, I almost ALWAYS ask for a build log, and a truthful Good/Bad report.

It it works, great!
If it doesn't, we know what not to do. This is the way of design.
Build, fail, reconfigure, build, fail, reconfigure, SUCCESS! Or not success, because we were going down a dead end.


If it keeps the same temp, but absolutely silent, that is a success.
If it heats up too much but still silent, that is probably a fail.
If it pees mineral oil all over the floor, that is a different kind of fail.
etc, etc...

I know, was only playing around. I know I ain't the first, was just hoping somebody on here had some pointers.

One of the things that has impressed me most about the oil immersion plan is that if it was worth doing it would be done more often.

I salute your spirit of adventure

The cooling issue .... what is the surface area of the fins of a stock cooler? How does that compare to the external surface area of the fish tank?
I do not think you can immerse a hard drive. They are vented [ with the exception of some helium filled models] and oil getting in will surely ruin the drive

That's an extremely good question, and one which I'm now realizing I don't have an answer to. I'll have to compare.

A conventional hard drive, and a disk drive, cannot be immersed, you're correct. I'm debating doing a slim disk drive above the oil, but I don't think I will for logistical reasons. There will be no mechanical hard drive in the tank, just an SSD with the OS and codecs and whatnot. The rest of storage will be done through NAS in a different room, so that part should be okie dokie.

 

[RomeoReject]

OK, so while I wait on my supplies, I can show off what I've got. Note, I swapped the MSI board for a Gigabyte one, as it had a better audio solution.

 

[mjslakeridge]

Even the PSU can go in the tank?

 

[ccampy]

Posting just to keep track love yo see how this works out

 

[RomeoReject]

Even the PSU can go in the tank?

Yep! Some people elect not to, as the PSU adds more waste heat in, but given the amount of wattage in this system, I don't foresee it being an issue.

Posting just to keep track love yo see how this works out

Thanks, that makes two of us. =P


Really wish I had a modular PSU, because I'm realizing I'm only going to need three connections off my PSU, the rest are all just a waste of space... Grumble grumble...

 

[RomeoReject]

Apologies for the lengthy delay, the girlfriend and I just finished moving in to our first place, so I was quite busy.

Anyways, have Windows 7 installed and running on the system just sitting exposed in the air, and first impressions are TERRIBLE. Without an enclosed system to keep it cool, temperatures shoot up rapidly (To 51 degrees on CPU, and a whopping 65 degrees on GPU, with no load on either) and it's louder than the apocalypse to run. Just looking for the cheapest mineral oil I can find, then I'll pour it in, test, and then see how it fares with an aluminum top. If it's still hot, I'll nab a couple 200 or 230mm fans and see what difference that makes.

 

[USAFRet]

Apologies for the lengthy delay, the girlfriend and I just finished moving in to our first place, so I was quite busy.

Anyways, have Windows 7 installed and running on the system just sitting exposed in the air, and first impressions are TERRIBLE. Without an enclosed system to keep it cool, temperatures shoot up rapidly (To 51 degrees on CPU, and a whopping 65 degrees on GPU, with no load on either) and it's louder than the apocalypse to run. Just looking for the cheapest mineral oil I can find, then I'll pour it in, test, and then see how it fares with an aluminum top. If it's still hot, I'll nab a couple 200 or 230mm fans and see what difference that makes.

So you have the bare system just sitting in the tank? Yeah, that will be warmer than if it was in a case.
What CPU cooler do you have on it?

 

[RomeoReject]

Yep, just sitting there all on its own, with the only airflow coming from the open patio doors and windows. Just have the stock CPU cooler on it (And not the Wraith, the old chunk of aluminum AMD cooler).

 

[USAFRet]

Once you've gotten the oil in the tank, how will you remove the heat from the oil?
Still going to put fins on the alu cover?

 

[RomeoReject]

That's the plan, yep. If that proves to be too inefficient, I will install fans to help with circulation of the oil. If that STILL isn't enough, I'll look in to forcing some air over the aluminum. Hoping I don't need to, as I'd like a media centre to be completely silent.

 

[USAFRet]

Keep us posted. This will be useful for future oil tank people.

 

[GlomGubben]

how is the project going? 😀