Immersion Cooling 4-6 S19 or Similar Units

I have recently begun a new mining venture and am ASIC mining. Not my preference, but it’s another adventure to say the least. I have 4 units now and I got them knowing I wanted to immersion cool. I don’t want this to become a cost debate of air cooling vs immersion cooling. I do have costs in mind, however I have a LONG term vision in mind as well. Immersion will pay for itself in time due to how I would like to use it for heat reclamation purposes and to keep things quiet.

Why do I want to do immersion cooling:

  • It would allow me to utilize the heat from the miners very effectively (hot water for the house, heat for the house, hot tub, heated walks to keep snow melted, in floor heating in any new expansion, and a myriad of other possibilities in the future as I think of them).

  • Noise: This one seems obvious and anyone that has these can relate

  • Miner Longevity: The word on the street is the miners should see a longer life cycle with respect to hardware failure, proof anyone? I would like to find someone that works at an immersion mining facility to confirm this.

  • Maintenance: I always like to keep my equipment clean, so I wouldn’t have to take the miners apart and clean them except for when they went into the tanks for the first time. There could be additional maintenance with the immersion and heat reclamation system though. This might end up being a wash.

*Overclocking: I wouldn’t go crazy with this, but it would be nice to be able to do some overclocking when/if it makes sense. I would be able to overclock with more stability and less likely be prone to hardware failure due to the immersion cooling.

My general heat reclamation plan:
Immersion Cool tank with a dual loop. The dual loop will allow me to transfer heat to other things and then lastly through the dry cooler at the end to make sure the coolant is sufficiently cold. This is what a very very rough system might look like linearly.

Miners’ hot oil → heat exchanger → glycol or similar mix → 120G water heat storage tank → any other items I want to heat → dry cooler → Miner tank cold input

This is very one dimensional, but you get the idea. The water heat storage tank will feed a hot water tank in the house to supply already heated water to the hot water tank. This basically makes the hot water tank hardly have to work at all except to maintain the temp. Looking at cost. I have two hot water tanks and they state about $500 a year to operate. Let’s just say that’s what it is. This could effectively save $700-1000 a year in hot, not to mention I would have AMPLE hot water with a 120G reserve tank. I would actually eliminate one tank too and keep it as a backup, giving me 160G of hot water as opposed to the original 80 (2 x 40).

I don’t want to get into details too much at this juncture. Where I struggle is to pick an immersion system. I have been reading and researching for several months. I want to go with a system that is already designed and basically ready to go out of the box with a dry cooler. I will work in heat reclamation after I am up and running because this will take time.

I originally saw the octotank12 that octominer is releasing and I was quite excited about this. Upon doing more research and thinking of the design, I figured it would be better to have a single larger unit. I then looked at foghashing’s setups, single and double (C1 and C2).

  • There would be less moving parts and maintenance (negative is if it goes down the whole operations stops)

  • In the summer I can leave the unit in the garage where the heat from the tank is not a problem.

  • If I had individual tanks like the octotank, I would have to move them outside (octotank is rated for outdoors). I estimated the octotank would weigh in around 300lbs with an S19 and fluid. Not to mention the fluid would be sloshing everywhere while moving.

  • Easier to expand when/if I want to add another miner or two. Pretty much no additional cost or work.

I don’t want to bash on any tanks that I have found or companies, but I will mostly say that I wasn’t keen on a particular tank and why. My reasoning could be wrong and please correct me if you think so.

  • Fog hashing B6D or B6. The B6D (3 phase dry cooler and can be run on 240v single phase) is a single loop, won’t work. About $6500 delivered to the US with fluid. The B6 is more or less a tank and then they add on what you want. I can get a dry cooler and heat exchanger for a dual loop with fluid, however I have to source/figure out my own pump for the second loop. This was configured all for 240v single phase. A little less than $7k.
    Immersion mining home mining – FogHashing

  • DCX. I don’t know, I have heard some mixed things on this and when I ask questions I mostly get told to look at the website which doesn’t have what I’m inquiring about. I’m not too hot on this setup.

  • Box Technology: I didn’t scour this as much as the others, however they utilize a cooling tower vs a dry cooler. It could be a great system, but it doesn’t fit the needs as far as I can see.
    40KW Immersion Cooling BOX - BoxTechy

  • FlameIT. Great responsiveness and knowledge. He is really just building 12 unit tanks and larger now, I think. He has a couple older tanks that are up for grabs. Kind of expensive for what his tank is IMO. Probably close to 6k delivered with fluid with no pdus or breakers etc… Just a tank, exchanger, pumps, and fluid. He is developing some great stuff though and I will continue to follow him.
    Edit: He does have smaller tanks as well and from my understanding his newer tanks will incorporate the electrical to run miners.

  • Aiproenergy: hotbox liu plus - interesting concept, but not for me. It is a pumpless oil system where the fans on the miners are responsible for circulating the fluid. It just seems like more to go wrong IMO and the system wouldn’t be flexible. It does have a dual loop for cooling the oil. You have to have aftermarket firmware too in order to control the fans.
    HOTBOX LIU Plus allows stable overclocking of Antminer S19 from stock 3250W to 6500W

  • Apexto: This one looks decent as well and looks quite similar to what I’ll show next. I have not dug into this tank/system much.

  • Asicshield/cryptomininglab: ASX6 - Some of the options I’ve shown so far have “bells and whistles” that I’m not really certain are necessary for a home setup where you might have one or two of these tanks. Most notably foghashing in this category. I have spend the most time looking at foghashing and asicsheld. The asicshield IMO might be the sweet spot. It is simple yet, I think, going to be very effective. From what I can tell the exchanger is larger than most tanks, the pump is quite large for the water loop, it has temp shutdown based on oil temp, and an oil filter before the oil goes into the oil pump from the tank. I have not seen this on other tanks. It is removable and can be cleaned. The bottom flow plate can easily be removed and if you need to make a different one then you just get one CNC cut at a local place. Most other machines the flow plate can not be removed very easily or at all. His support and responsiveness has been great. He is probably sick and tired of talking to me. He can supply immersion fluid as well with this system. The system looks good and I do like that there is a lid that you can see through. I think with the simplicity of the system there is less to fail. I think the pdu plugs on the back leave something to be desired, but perhaps I can get those changed. Pricing is on par with most other units.

I have very heavily looked over the asicshield, octotank12, and B6/D setups. Most of the others had something immediately that I didn’t like or they didn’t work for me. It was also important to be able to change the immersion flow plate. I can see a lot of these mining companies releasing specifically immersion cooled units just like whatsminer/microbt just did. If you have a tank build specifically for the current S19 and you can’t change it then you’re SOL.

PLEASE let me know your thoughts, opinions, experience etc… If you have another tank you would suggest, feel free to let me know and I’ll look at it.

Edit: I am not affiliated nor do I receive anything from these companies.


Asicshield looks like your best bet. Bigger pump and the additional features. Can’t wait to see this all come together. I’m going to use you as a Guinea pig to see if I could possibly heat my pool year round with your set up!

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I guarantee that you can! My only other concern really at this very moment is whose immersion fluid to use. All of these places provide their own immersion fluid. Alternately, you can go with bitcool or other places that claim to “make their own” fluid. The question begs, do you pay 2x as much for bitcool or are the other solutions just as good or better and half the price?

I think while I research and think on this that I will begin making a more complete rough draft of the heat reclamation system. Once I get it mostly drawn on paper I will probably draw it up on autocad or a similar program.

Again, if anyone as experience, opinions, suggestions then PLEASE throw them this way.

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One other thing that I have been back and forth on a lot of times is the cooling fluid. Most of these companies offer their “Own Fluid”, however I have hesitation with that. It is very tempting because it is definitely cheaper, even shipped from china or wherever overseas. I think, not with definitive proof, that most are either user “mineral oil” or “transformer oil”. This is most definitely not an area of expertise for me, however it may be worth paying 50% more or so for “Bitcool 888” to ensure success.

If anyone has unbiased experience or knowledge on this, please share.

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I have settled on a unit. I ended up going with the “Asic Shield” ASX6. I just sent off the wire today for it. It was all a very hard decision to make, but a decision had to be made. I’d imagine it will land here in about a month. Once I can get caught up on some things I’ll start a more “professional” design on paper for the heat reclamation system.

Once I get the system and have a chance to give a good look and start setting it up then I will order up some bitcool (BC-888). I like to take one step at a time.

One of the other things that drew me to BC-888 was that it is “non-toxic”. I’m not saying to drink it, but if you’re utilizing a heat reclamation system that could potentially come in contact with drinking or bathing water then you definitely don’t want something toxic in the heat exchanger. If the system is in place long enough it will eventually fail. I will be using a non-toxic “glycol” mix for the water side of the heat exchanger as well. The odds of the immersion fluid getting into the drinking water in this scenario is next to zero, but that doesn’t mean it can’t happen.

Hello @live4soccer7, Paweł, CEO of FlameIT - Immersion Cooling here.

First of all, thank You for nice review and well done for doing great job (research).

I would like to write something about our liquid. It’s not “mineral oil” nor “transformer oil”. When we have started our journey with immersion, back in 2018, our key point was to have a product that will be:

  • first of all, safe to human
  • safe for electronics
  • low viscosity
  • good thermal conductivity
  • free from sulphur, nitrogen and aromatics
  • liquid has to have best oxidation and thermal stability
  • non-evaporating
  • long lasting

We have tested mineral oils (HotPots #2 bąble - YouTube - april 2018 and our FIRST of FIRSTs proof of concept tanks - check how low viscosity this mineral oil has). We have stoped using mineral oils after that test (after 2 month cables got almost ROCK HARD and this oil has really high viscosity, I don’t remember if we even checkd thermal conductivity). That liquid, which we have learned later, was not that great in reagrds of thermal and oxidation stability and had some other issues like water content inside.

Historical moment: First immersion [mineral oil, DO NOT USE IT]: FlameIT: January 2018 Febru HotPots #1 - pierwsze uruchomienie/first ever prototype - YouTube

Over they years, we have made really good reasearch about what we can use in our solutions. We have tested some of products and what is most important we have found a chemical plant that we are working with and that is delivering us our FITCool products. Those are IV group oils (best performance), fully synthetic products. In terms of performance our products are AT the moment (and with our best knowladge), best of the best in the world: Immersion cooling liquid

Our liquid in action: FlameIT - Immersion Cooling - FITCool6 liquid in action - YouTube


  • Kinematic Viscosity @40oC : 6 cSt (we can lower that value way below 4 cSt but there are some cons to do so)
  • Thermal Conductivity @ 40°C: 0,142 W/m*K (how fast liquid can take and give heat, important when calculating heat exchangers and basically fluid performance)
  • no water content at all: our liquid at -25 oC FlameIT - Immersion Cooling liquid in -25°C - YouTube [I am aware it’s not a labolatory]

Talking about labolatory: Chemical plant we are working with is giving us an option to send samples to them. They will for us do proper, long term material compatibility tests if needed using industry standards.

If You find anything better please let me know!

We always test things on ourselves first. If we test anything at the client’s, he is always INFORMED about it.

One more, super important thing, which most of companies won’t tell You about, is material compatbility. EF made really great move in that matter and I really love it. There is no liquid that will be compatible with every material. You always have to keep that in mind!

Because of above we have excluded:

  • 3M liquids (BTW 3M a month ago stopped producing them…) - they are super expensive to buy and they evaporate (tank construction issues), but they are SUPERB in terms of removing heat
  • we never even tried transformer oils (cause cancer) but they are cheap to buy and have quite good parameteres (let’s say quite acceptable)

Electrical/electronical side of our products: We are designing also our own PCB to control and monitoring our tanks:

FameIT - AC Mains and Zero Crossing Detector at work: FlameIT AC Mains and Zero Crossing Detector - frequency testing - YouTube

To sum up and going to point:

  • we are doing tailor made solutions (just tell us You needs)
  • we do include brakers in our products :wink:
  • next gen tanks will have PDUs included
  • we always try to keep our clients educated as much as possible to they know what they are doing
  • we have in our offer: 2 / 4 and bigger ASIC tanks (tailor-made - remember) | GPU dedicated tanks

I will be happy to hear Your feedback on tank You have bought. Good luck.

Have a good day, Paweł

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The immersion system has shipped. Just awaiting arrival now. I came up with another idea to possible cool the immersion fluid without a dry cooler. It’ll have to be a wait and see how it all works situation, but I already plan on having a 120 gallon hot water storage tank to cool the immersion fluid and then provide the house with hot water to feed the traditional hot water tank/heater. I’m on a well, so the cost of water is negligible in the scheme of things and really this wouldn’t use a whole lot of water anyways (I don’t think). I could simply have a temperature probe on the hot water storage tank and if the temp exceeds a threshold then I could have it dump the water outside into a pond nearby and then cold well water will enter the storage tank. I someone don’t expect that too happen to often, but again I’d have to just wait and see how quickly that 120G tank heats.

I am hoping to get the immersion system either late this week or next week.