Immersion Cooling

What is Immersion Cooling ?

Immersion cooling is a type of liquid cooling used to moderate data center equipment temperature by submerging it in a cooling fluid. Server immersion cooling helps to dissipate heat and keep components like CPUs performing optimally. Immersion cooling systems prove to be more efficient than traditional data center cooling methods (like computer room air conditioning, or CRAC) due to the increased thermal conductivity of most liquids compared to air.

Because 1-1.5% of electricity use across the globe is attributable to data centers, companies have been innovating to find a liquid cooling solution that can reduce that energy demand. Dielectric fluid immersion cooling is one solution that could increase CPU density in data centers while consuming less energy.

How Does Immersion Cooling Work?

From a fundamental level, liquid immersion cooling data center components involves dunking them in a dielectric fluid. From there, the process can look drastically different depending on whether a two-phase vs. single-phase immersion cooling system is being used.

Single-Phase Immersion Cooling

In single-phase immersion cooling, heat from the immersed server components is transferred directly to the surrounding fluid. However, the dielectric fluid does not undergo a “phase change” from a liquid to a gas. Instead, the fluid is cycled out of the immersion tank by a coolant pump that runs through a heat exchanger and is returned to the immersion tank at a lower temperature where it continues this heat transfer cycle.

Two-Phase Immersion Cooling

In two-phase immersion cooling, server heat boils a low-boiling-point fluid, creating vapor that transfers heat to condenser coils. The coolant is then circulated to an external cooling system and returned at a lower temperature. A major drawback is that the chamber must remain sealed during operation, making maintenance slow and costly—up to $5,600 per minute of downtime.

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Benefits of Liquid Immersion Cooling

From higher efficiency to less noise within the data center, server immersion cooling offers myriad benefits for your IT operations.

Immersion Cooling Uses Less Energy than Air

There is a lot of debate when it comes to air cooling vs liquid cooling in data centers, and ultimately it often comes down to power effectiveness. The average power usage effectiveness ratio (PUE) within a data center can be measured by dividing total energy consumed by energy used by computing equipment. This means that as PUE gets closer to 1, efficiency is improving. According to The Register, PUE for a traditional data center in 2022 was approximately 1.58, while single-phase immersion was able to bring this number down to the 1.05 to 1.10 range.

Immersed Servers Do Not Require Air Conditioning

Traditional data center infrastructure would indirectly cool servers via raised floors, CRAC units, and strategically placing units on the data center floor. Immersion removes this requirement which accounts for around 35-40% of the power used in a data center. This eliminates the need for hot and cold isles, raised floors, and CRAC units.

Saves Space

Not only does immersion cooling improve the energy efficiency of data centers, but it can save valuable space as well. According to a 2023 research article, immersion cooling only requires about one-third of the space to that of an air-cooled configuration. One of the main contributors to this efficiency is the improved rack power density from not having to allow for air flow within servers.

Increases Rack Density

An average, fully populated data center 42U cabinet holds 5-7 kW worth of server compute. Alternatively, fully populated 42U immersion racks can hold over 380 kW of compute. The safe computing density advantages that come from liquid immersion cooling solutions cannot be disputed. Not to mention, these immersion tanks can be installed anywhere with a power and network hookup.

Current Project Highlight: Poland

Our latest data center development in Poland is built on next-generation cooling systems, designed for energy efficiency, scale, and long-term ROI.