Originally posted on Data Center POST

By Cathy Chu, Global Strategic Marketing Director, Consumer & Electronics, Dow

The promise of 5G networking for connecting our world includes higher multi-gigabit-per-second (Gbps) peak data transfer speeds, ultra-low latency, higher reliability, massive network capacity, increased availability and a more uniform user experience. However, achieving this performance places heavy demands on physical and digital infrastructure and endpoint devices, including higher operating temperatures, increased electromagnetic interference (EMI), and a bigger impact on the environment. Consider:

  • The growth of data centers since 2010 has resulted in a 30% increase in their collective energy requirements.
  • 40% of the energy needed by data centers is for essential cooling systems.
  • 1.5% of the world’s electricity consumption is currently accounted for by data centers.
  • One billion liters of water are needed by data centers every day in the United States alone.

By implementing more efficient and sustainable cooling technology solutions, data center operators can lessen energy, water, and land consumption, leading to significant cost savings.  Immersion cooling is a technique in which electrical and electronic components, including complete servers and storage devices, are fully submerged in a thermally conductive but electrically insulating liquid coolant. This novel approach to cooling reduces a data center’s energy use by over 60% – which is better for the environment and the bottom line. Furthermore, water consumption in immersion cooling amounts to less than one percent of the total water used in traditional cooling methods. 


When it comes to immersion cooling, there are two options available to cloud and data center operators: single-phase and two-phase. The key difference between single-phase and two-phase immersion cooling is that the former stays in its liquid phase while the latter transforms from a liquid into a gaseous state. In single-phase immersion cooling, heat is transferred to the coolant through direct contact with server components. The coolant then returns to the server from a heat exchanger at a user-specified temperature. Unlike two-phase immersion cooling, the coolant does not boil off and is cooled via a heat exchanger. In two-phase immersion cooling, the fluid boils from the server heat, transforming from a liquid into a vapor that passively condenses back to a liquid form when it directly contacts a water-cooled condenser. 

Single-phase immersion cooling offers data center operators several benefits over traditional two-phase immersion cooling systems, including reduced operating expenses and environmental health and safety (EHS) risk, as well as improved hardware stability. While two-phase immersion cooling is an option for data and cloud centers, there have been recent concerns raised by the Environmental Protection Agency (EPA) over two-phase coolants because they typically depend on Poly-Fluorinated Alkyl Substances (PFAS) that are considered hazardous. Single-phase immersion cooling, on the other hand, can be conducted with fluids that are safer for the environment, making it an ideal solution for data center operators looking to utilize more sustainable practices. 


To date, the three primary liquids used for immersion cooling are fluoro-carbon fluids, synthetic oil, and silicone fluids. While all of these provide significant improvements over air-cooled systems, each has certain performance challenges:

  • Fluoro-carbon fluids are relatively costly and present significant environmental, health and safety (EHS) concerns, especially in the event of accidental leakage.
  • Synthetic oils have concerns of flammability and thermal instability compared to other alternatives.
  • Silicone fluids provide significant cost advantages but are incompatible with other silicone components.

However, the solution to these challenges may lie in hybrid silicone-organic fluid. Designed for single-phase immersion cooling, this type of technology can deliver outstanding thermal conductivity for efficient and cost-effective heat dissipation and a remarkably low Global Warming Potential (GWP) score. Hybrid silicone-organic liquid can get into small spaces closer to the materials that need cooling, and there is no need for chillers, computer room air conditioning (CRAC)s, computer room air handlers (CRAH)s, or raised floors. It can also support the growth of server load densities and increased computer performance while substantially reducing data center footprint requirements and power usage. Lastly, it removes the challenge of compatibility with other silicone components for data center cooling operations. 

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