Topic: Why so few immersion cooled custom builds/Mods? - page 3. (Read 5464 times)

For decades I've worked with immersion cooling all the time in HVDC supplies producing 10's of kwatts and will categorically state the thermal xfr fluid is a key to it. Yes in my case has to withstand 30-50kv but more importantly has to be thermally stable, have excellent heat transfer ability and, most importantly not attack other materials. Off the shelf mineral oil attacks hoses, seals, and electronic components. Due to its viscosity it pumps/flows very poorly.

Yes having a horse trough (preferably a real metal tank) full of miners in a fluid like the one from Clearco should work great. I use it in work and is near-water thin so pumps/flows very well. So far only caution about materials is pure silicon-rubber -- makes it swell.

Since miners like a high temp, say a bath running around 50-60C, that makes for a great delta-T between the fluid and outside ambient resulting in a smaller hot-side air/fluid exchanger needed.

Yes the Clearco fluid is pricey but way way less than Novec is. Plus of course, if left in the open on a very hot day or in case of a drastic thermal event caused by no flow/pump & fans status/overtemp cutouts, several hundred $ (or several thousand $ if Novec) of it does not go away....

I'd like to see more immersion cooled mining setups as well...  Having the benefit of learning from someone else's mistakes might give me the confidence to try it myself.

Please ref https://bitcointalksearch.org/topic/--1604125 dealing with liquid/immersion cooling a s9.

Mineral oil is NOT a good thing to use:
Only moderate heat-capacity (how well it absorbs/releases heat)
Viscosity highly variable with temp
Even when warm, is still not easy to pump
Attacks many plastics including Nylon (PCIe connectors), PCV (wire insulation) and elastomer (rubber) capacitor seals.

Much better choice are thermal transfer fluids designed for use with electronics and electrical parts such as http://www.clearcoproducts.com/dielectric-silicone-fluids-sto-50.html

Water-thin meaning easy to pump and flows very well around components, does NOT attack rubber/plastic, etc., very good thermal properties.

Yes a heat exchanger of some sort would be needed too, agreed. It was a simplification and a whole other topic of how to build one.

But on that topic it reminds me of other posts I've read here. People setting up their miners in the garage due to noise/heat and opening a air inlet through the wall, and exhausting through another hole. It just screamed contamination from ingesting bugs, leaves in autumn or anything wanting to nest somewhere warm.  What about the other advantage of having the miner indoors and pumping the oil through hose to the heat exchanger at a more suitable location? I just think that as everyone's circumstances and climates are different depending on where/how they live yet we all have the same air in/out push/pull fan arrangement. Is that really perfect for the majority?


***edit*** the garage example aside, if you look on youtube for "quiet antminer" some people have gone to some extreme lengths to continue air-cooling the miner when perhaps another method could have been adopted.

You know the mineral oil just absorbs the heat anyway and mining hardware generates a lot of heat so you need some kind of cooling for the mineral oil itself equivalent to dissipating the same amount of heat the air cooling on the hardware does. The overall set up would be very expensive; that's the main reason it's not done.

Okay, I know at a glace this could come across as a stupid topic but I would really appreciate it if an articulate discussion came of this...

Cryptocurrency mining hardware is very expensive, and we should look after our rigs as best we can. After all, the build up of dust reduces air flow, raises temperatures, kills blades/miners.

However in my (limited) experience, the components that get killed on the boards aren't often the mining chips as you may think, but the often disregarded power regulating components. Mosfets, capacitors etc. Without this becoming a rant at some manufacturers that under-power their boards, over-stress the power supply circuitry, so it runs fast until it out lives the warranty. Some of us are doing this at a hobby level and don't have the high turnover of constantly getting the newest model of ASIC. We need to make our units last.

So my next point is regarding temperature. For one, people refer to overclocking ASICs and state the temperature that their interface is telling them the unit is at. Often this is wildly inaccurate, giving a surface temp of a PCB or once again measuring the mining chips and neglecting the Mosfets. Yes, when you overclock a mining chip it may raise in temp from 60 to 75, and you'd think with it's upper limit of 125 that'd be fine. But what's the temp of the Mosfets, capacitors etc we're stressing driving this equipment? As I said before it's not often the mining chip goes pop.

So my last point and the punchline really. The power supply components are often smaller than the mining chips in terms of surface area. They are also of unequal heights and this makes it very impractical to fit heatsinks. The designer places them in the airflow as best they can, but as I mentioned, with the enclosure around them this can be partly obstructed especially over time if not maintained. Is the answer not fluid cooled systems, immersion I mean, that give even heat exchange across every component? No matter how small?

I get that could be a logistical nightmare to ship. But I've seen very few hobbyists adapt their miners this way too. Am I missing something? Or if it ain't broken don't fix it?

But lets be honest on a technical level it would be no more complex than assembling a simple frame and dropping it in a fishtank of mineral oil. (A kind of gross simplification).
What about people that want to mine with an S7/S9 at home but can't put up with the noise?

A few thoughts.
Dan
Some interesting examples on youtube.