Immersion Cooling: Take a Dip, The Oil’s Fine

By Tim Mandell and Crystal J. Milburn

In the last blog, we covered worldwide data center usage remaining steady over the past 12 years despite significantly increased internet use. Overall power usage is right around 1% (then and now) thanks to a number of innovations on both the technological and operational sides of the equation. Immersion cooling is one of the ways in which data and mining centers have been able to offset the growing electricity demand, while still satiating the ever-increasing demand for hash power.  

Immersion cooling has been around for a while but hasn’t gained much traction due to the significantly higher upfront CapEx costs of the necessary equipment. We’ve seen figures as high as $400 per kW more than the traditionally air-powered mining center. This blog, a summary of Okada’s article in Bitcoin Magazine, compares the pros and cons to help achieve immersion cooling clarity. 

Despite the sticker shock, immersion cooling has recently gained traction with major industry players such as Riot Blockchain, Argo Blockchain and others. These crypto whales are betting big on the efficiency boost that the method of heat dispersion is touted to provide.

If immersion cooling is something you are interested in, please click through to the survey on this page, as we’d like to hear from you!

What is Immersion Cooling?

Wim Hof’s ice baths have become quite popular in the fitness world. Athletes who have run long distances, lifted heavy weights or put their bodies through extraordinary feats find solace in taking a dip in an ice bath to cool down (among other health benefits). Immersion cooling is the ice bath for your ASIC (application-specific integrated circuit) miners, a.k.a. mining rigs. 

Immersion cooling employs circulation pumps and special liquids designed to work with electronics vs. the traditional air cooling methods most of us are familiar with. Okada expands on this technique, “Immersion is the practice of completely submerging, or immersing, the mining rig in a thermally-conductive liquid with greater insulating properties than ordinary air. Perhaps counterintuitive at first, dunking your energized electronic mining rig into a specially-designed liquid allows for greater heat removal from the always hot and hashing computer chips.”

Since liquid has a greater heat transfer capacity and insulating properties than air, it’s the ideal ASIC cooling medium. Thermal energy is transferred from the hot surface (the chip’s heatsink) to the cool liquid, which is far better at transferring heat away from heat sources than air. This leads to an optimal flow rate of the dielectric liquid over the hashboards and consistent proper chip operation.

Increaed Profits + Other Benefits of Immersion Cooling

The argument to be made here is that the more efficiently we can cool the mining rigs with constant, optimal temps, the longer the mining life and the better they will hash (in the short and long run). All of that adds up to more profit for the miner. Take a look at some of the other benefits of immersion cooling below. 

Prolonged Death Rate of Mining Rigs 

Miners last up to two years longer thanks to the prolonged performance, which is even more attractive as hardware costs increase.

Increased Terahash per Second (TH/s) 

Due to easier ASIC overlocking = optimum hashing power efficiency. According to some sources, 40-60% more hashrate. 

Reduced Mining Rig Footprint

Increased hashing power leads to more BTC earnings with fewer machines needed for the same earning power. 

Eliminated Damage 

From dust and other air particle build-up on the mining chips. 

Mine in More Locations

Not confined to areas with low power rates which opens the miner up to remote locations or extreme climates. 

Silence

The constant humming of air-cooled mining rigs is reduced to barely detectible white noise. 

Recycled/Reusable Energy + Decreased Utility Bills

The heat rejection can be recaptured and repurposed for heating water or other amenities in your facility - or - complementing your primary HVAC.

Reduction of Alleged e-Waste

If you believe mining rigs cause e-waste, then it could be argued that the ASIC failure rate is reduced and therefore, e-waste would also be reduced. It’s also been proposed that immersion cooling can resuscitate older less profitable machines. 

Downsides to Immersion Cooling

High Upfront Costs

As mentioned earlier, this is not the cheapest cooling option on the market.

Compatibility

Miners must know which liquids work with which machines and which firmware. 

Set-Up Time

This is not a plug-and-go option. There are many moving parts, such as piping, tanks and pumps which must be sealed in an airtight manner or you risk leaks.

Higher Risk for Error

Among other things that could go wrong, if the cooling medium isn’t recirculated between the tank and the heat exchanger at a precise rate, the mining rig is at risk of overheating.

Messy

Maintenance or relocating your machines means removing them from the oily liquid and cleaning them off.

Bitcoin Magazine said it best, “The name of the mining game is effectively scaling operations with minimal additional costs, such that the skill of scaling a Bitcoin mining operation is a form of art, expressed in the medium of cutthroat expenses.” 

We hope this helps clear the air, or the immersion cooling liquid, for you. We are by no means immersion cooling experts but if we can make it make sense for you and for us, it’s something we’re open to exploring. In fact, we’re taking it under consideration as a strong possibility and we invite you to complete our survey as we explore options.