Data Center Immersion Cooling

Data center immersion cooling is a liquid cooling method that involves submerging server components in a dielectric coolant such as mineral oil. The coolant has a high coefficient of heat rejection and low thermal resistance, which protects the equipment that is being submerged in the liquid. Since the liquid is a better heat conductor than air, immersion cooling is highly energy efficient.

Types of Immersion Cooling

There are two types of immersion cooling that can be employed within a data center, and they are categorized by the properties of the coolant used. The optimal immersion cooling technique is dependent on the characteristics and needs of the facility.

The two types of immersion cooling include:

• Single-phase immersion cooling. With single-phase immersion cooling, the state of matter of the liquid coolant remains the same. The coolant is pumped into a heat exchanger where heat is transferred to a cooler water circuit. There is little to no risk of coolant evaporation, allowing the system to use an “open bath” technique with the coolant. The servers are installed vertically into the coolant bath, which consists of a hydrocarbon-based dielectric fluid similar to mineral oil. It is the simpler of the two submersion cooling options, making it more affordable and easier to maintain.
• Two-phase immersion cooling. Also known as evaporative cooling or flow boiling, two-phase immersion cooling involves the coolant existing in both a liquid and gas phase. This system uses latent heat, which is the thermal energy required to change the phase of a fluid. Energy is transferred from the heat source to the fluid, causing the fluid to boil and turn into a gas. The gas rises above the fluid pool to a condenser that turns the gas back into a liquid which flows back into the pool. This type of submerged server cooling is most ideal for high density racks as it has a higher cooling capacity, but it is more expensive and potentially harmful to the environment.

What Are Some Use Cases for Immersion Cooling?

• Supercomputing. Supercomputing for scientific or engineering activities places high demands on compute devices which require a large cooling capacity. Since high-performance computing (HPC) requires intensive power for the processors and cooling, immersion solutions can drastically decrease energy consumption. This allows for innovative applications and makes the equipment more manageable.
• AI and machine learning. Artificial intelligence (AI) requires intensive computing resources that use high density CPUs and GPUs. Cooling these processors has historically been challenging, but liquid immersion cooling raises the limits of the processors to enable faster and smarter computing. The immersion in a dielectric fluid allows for practically unlimited cooling, which allows the AI to run on as much hardware as necessary with the most energy efficiency.
• Blockchain and cryptocurrency. Crypto applications often employ dedicated hardware like GPUs and ASICs that require considerable cooling, and mining cryptocurrency requires massive computational resources. Efficient heat management technology, such as immersion cooling, allows these intense processes to run smoothly by providing safe overclocking.
• High-frequency trading. The finance industry has increasingly used higher performing computers for low-latency transactions. Since such large amounts of money ride on mere milliseconds, the cooling capacity and processing enhancements of immersion technology are much needed. Finance is also heavily centered in busy metro areas, causing the data centers to operate within limited power and space envelopes. Immersion cooling can deliver more than enough capacity in these areas.

Monitor and Manage High-Density Racks with DCIM Software

High-density racks are great for fitting more compute capacity in a smaller footprint, but cooling and managing them can be a struggle.

Data Center Infrastructure Management (DCIM) software simplifies high-density rack management and enables you to intelligently increase your density without risking downtime.

With DCIM, you can easily identify and remediate hot spots, set thresholds and alerts on power and environmental conditions to know before you have a serious problem, automate power capacity planning to eliminate stranded capacity, get at-a-glance views of the health and capacity of all your sites, visually document all cabling infrastructure, and visualize the weight capacity of each cabinet in 3D.

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