I'd say you don't need to guide the air, but your solution for oil flow management seems great! Maybe I'll be able to design the tank to have removable guides, so we'll be able to test that hypothesis. That would be fun. I'm guessing that forced convention will make a significant difference. I pred...

Evaporative cooling! A little followup on this evaporative cooling concept -- I had a 3D game paused for a while, came back and noticed that the tank's oil temp had risen to 55C (131F). Even with a couple small (and quiet-ish) fans pointed at the tank. That was a bit hot for my comfort. So, I wrapp...

Hmm, this is interesting.

I draped a wet cloth over my oil aquarium and pointed a room fan at it.

With the computer on standby (drawing 4 watts, effectively off) the tank oil temp got down to 65.6F / 18.6C.
That's below the room's ambient temp of 70F / 21.1C.

Evaporative cooling!

Nifty.

(edited to add pictures and more detailed description) Another option is to fold it in a zig-zag pattern to increase the surfaces facing both oil and air. Start out with a thin plate (or possibly a couple, adding up to) 50cm high and 400cm wide, to get a 2.0 square metres surface. Then fold it sidew...

jaganath wrote: it can be calculated if you have the Nusselt number:

http://www.cheresources.com/convection.shtml#natural

http://www.owlnet.rice.edu/~ceng402/ed1 ... index.html

Wow. That blows me away.

The overall heat transfer coefficient for a wall or heat exchanger can be calculated as: 1 / U A = 1 / h1 A1 + dxw / k A + 1 / h2 A2 (1) where U = the overall heat transfer coefficient (W/m2K) A = the contact area for each fluid side (m2) k = the thermal conductivity of the material (W/mK) h = the ...

The difference between copper and aluminium (about 400 vs about 250) isn't quite as large as the difference between glass and aluminium, so that may explain why the material doesn't matter as much if the choice is between copper and aluminium. It may matter when it's between aluminium and glass. I ...

How do you calculate how much heat you lose through a single one of those plates? What does it depend on? The material, thickness, surface area, shape, oil temperature, air temperature? I posted something about thermal transfer in this post: http://www.silentpcreview.com/forums/viewtopic.php?p=3959...

[Edit: oops, didn't mean to post this one. How do I delete a post?]

Even if the material doesn't matter, which I'll believe in an instant, can't you get a bigger surface area / volume ratio by finning the metal plates? It sounds a lot easier to get a finned metal plate than a finned glass plate. Oh, fins! Yes, I certainly agree with you there - glass fins would be ...

So isn't it possible to fully passively cool by using a larger aquarium and about 40 liters of mineral oil ? I think so - but maybe a small aquarium with oil will be sufficient. But I haven't even tried that yet, so it is unproven. My original motivation for using a double-hull design was to preven...

I would definitely go for submerged if I could make my aquarium-pc into a lava-lamp pc (have blobs moving around the aquarium). That's a pretty cool idea! The colored blobs in lava lamps are some kind of waxy/oily substance that won't mix with the water it floats in. The wax and the water parts are...

I have a pair of wiss snips. risspy is right: they are excellent.

But, Crisspy claims the straight (yellow) snips are useless. I disagree! I use them for opening the tough plastic packaging that so many computer supplies (cables, etc) often come in. :-)

The water evap rate is limited by the solubility of the water in the oil: its near 0. The mineral oil has a very very low evaporation rate at room temperature, I doubt its measurable outside a lab. Vinegar will not prevent algae, and it will smell nasty. I recommend a few changes to your setup: 1)r...

[Edit: continually updating the table with experimental results] Well, last night I started an experiment on evaporative water loss -- because, as I mentioned recently, I'm annoyed that I keep having to add water to my outer tank. I filled two identical glasses with water. Then I added a little bit ...

How hot does the water get? Maybe you just need some high temp loving sucker fish. :lol: Heh! I doubt any fish can tolerate these temps. The oil temp stabilizes at about 120F after approximately 12 hours of power-on time. Ambient air temp is about 70F, so that's a 50F temp delta. I think this temp ...

Just checking back in on this thread. Top marks for doing this "for real", drownmypc, and for the excellent detailed analysis of the results. Thanks, Bruce. It has been a lot of fun. I added an update to my other thread about problems (algae, mineral scale, evaporation) I had in my water tank. (I h...

which gives me a list of suppliers for the UK, however whenever they ring them they ask what grade mineral oil i want! I dont have a clue, any help? Hi, blundell. I'm guessing they wanted to know whether you needed "food grade", "medical grade", or "industrial grade", etc. I don't know precisely wh...

I drowned my PC in mineral oil 9 months ago. It has worked fine, although it hasn't seen heavy usage. The oil temp gets up to about 120F after about 12 hours of ontime, where it stabilizes (my basement is typically at 65F-70F). The oil tank (inner tank) was always pretty clean looking, except for th...

You'll need to include "oil vapor" as one of the downsides, if you're thinking about an un-sealed system. It smells terrible, and potentially has health impacts. I've had an unsealed system running for almost 6 months. No smell, no perceptible drop in oil level, air quality (my basement) seems fine...

My double-hulled oil system has been submerged since early February - about 5 months now. I use it intermittently for games and photoediting. It is off most of the time, but each week it averages maybe 5 powerons and about 5 hours of on time. It still works fine - no loss of performance, no function...

If the PC has a power output of 400 W (which is pretty high end), and the walls are a total of 0.6 m2, a 4 mm copper wall means a delta T of 0.06 °C. Aluminium will mean a delta T of 0.11 °C. The difference is practically immeasurable. WOW. Nice work, spookmineer. I was aware of the thermal condu...

you'd probably need a much higher flowrate to make up for poor heat capacity of min. oil (60% less than water). I agree. The upside of replacing the water in a conventional pump/tubing/waterblock/radiator setup is that spills won't fry your computer. But the downside is that you lose a lot of cooli...

I'm interested in discussing the relative merits of conventional watercooling (water blocks, tubing, pumps) versus oil-submersion (aquarium, mineral oil). No religion, please! I am not personally advocating either approach (although I have more experience with oil submersion than water cooling). I w...

I would still would love to see what would happen to the temps if you slid in a piece of metal, about the same size as the plexi the mobo's on, into the tank. maybe heavy gauge corrugated roofing? Okay, I tried it. I had a sheet of steel, about 1/16" thick, maybe 16x24. I stuck it into the tank lon...

I would still would love to see what would happen to the temps if you slid in a piece of metal, about the same size as the plexi the mobo's on, into the tank. maybe heavy gauge corrugated roofing? I would think it would really help a lot ...especially if the psu exhaust fan was aimed at the exposed...

Hi, wim. Yeah, I have a reserator2 sitting next to me (I tinkered with water cooling a while back). Lessee here...it's about 12 inches long, 11 inches tall = 1.83 sq ft without the fins. But there are 50 fins, each 11 inches long and 1 inch wide (at about 1/2 inch spacing). That's another 3.82 sq ft...

Hi, Bruce! I was happy to see that your results are pretty close to what you predicted with the spreadsheet. I was pretty surprised by that, really. I mean, so much of it is estimation and guesswork. I didn't think they'd be even close. I got the mineral oil from an agricultural supply store here ca...

Hmm, following up on previous post: so theory seems to be in the right ballpark, and my spreadsheet might be almost accurate. Now, suppose my mobo+GPU were pulling 500W. My spreadsheet predicts the water temp would have to be at 80C (=176F) in order to shed 500W of heat energy from a 20x10x12 tank G...

Earlier in this thread I gave tables on how quickly a hot aquarium would shed heat. Was theory in the right ballpark? Now that the system is plugged into a power meter, I can do a rough check. The power meter measures 115W at idle. The PSU is rated at 80+% efficiency. So that makes 92+W being delive...