immersion cooling

Immersion cooling is a type of liquid cooling. There are two types of immersion cooling based on dielectric liquid type – single phase and two-phase.

The server is entirely submerged in a tank with a particular non-conductive solution or oil, based on the cooling type, where heat generated by the immersed server is transferred into the cooling liquid. Single-phase immersion cooling method uses hydrocarbon liquids such as mineral, synthetic or bio oils, and two-phase method uses fluorocarbon liquids, i.e. fully engineered liquids as a cooling solution.


Single-phase liquid cooling

Single-phase liquid does not freeze or boil and does not evaporate, so it requires circulation of liquid using the heat exchanger to facilitate the heat transfer.


Two-phase liquid cooling

Just like water’s natural circulation, the hot liquid evaporates and re-condenses back into tank with a non-conductive solution. Circulation happens passively as a natural process of evaporation, so no extra cost is added for this step.

sola® immersion cooling system

RSI has partnered with Taisei and Shinohara Electrics to provide a two-phase liquid immersion cooling solution in Japan, enabling customers to significantly reduce data center energy consumption, improve power usage efficiency (PUE) and reduce operating costs and environmental impact.

How does it work?

The entire server is immersed in a liquid immersion tank filled with a special refrigerant with a low boiling point (56°C). The special refrigerant boils with the server heat and absorbs the vaporization heat. The radiator cools the refrigerant then the cooled refrigerant is returned to liquid in the tank. A dry cooler cools the water used in the condenser and circulates it. The cooling capacity of 50kW per immersion tank can significantly increase the density of the server compared to the conventional air cooling method.

sola® advantages


Higher Efficiency and Energy Saving

>90% efficiency advantage in the data centers compares to air cooling - including server power consumption and air conditioning costs.



Components are not subject to temperature variations, reducing failure potential & no cooling fans required, eliminating degradation from vibration.


Higher Computing

No need for heat sinks and cooling fans means computing parts can be placed closer, which can increase computing power by 10 times in the same space.


Lower Maintenance Requirement

Passive cooling system means no unnecessary parts to build or service, useful especially for remote locations such as edge computing stations.



No air conditioning and low maintenance requirements, it can be shrunk to expandable modules and deployed in confined spaces and extreme environments.

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