Synthetic Ester Coolants: Powering Safer, More Sustainable And Efficient Data Centers

Author: Logan, Personal Data Center Liquid Cooling Solution Development, Perstorp; Brent, Senior Manager of Thermal Design, Inventec Collection: 2025 OCP Global Summit - Expo Hall Sessions

Summary

Perstorp, a Swedish engineered fluids producer with 140 years of experience (acquired by Petronas in 2022), presents the case for using dielectric synthetic ester coolants as an alternative to PG25 (propylene glycol 25%) water-based coolants in direct-to-chip (cold plate) liquid cooling systems. The core argument is that water-based coolants, while thermally superior, create significant risks: leakage can damage high-value equipment because water is non-dielectric, long-term corrosion affects metal pipes and sophisticated cold plate designs, and water treatment requires ongoing quality monitoring. Current hardware-based leakage mitigation (detection wires, drip trays, electrical valves, BMC/RMC signal integration) increases system complexity and cost while still not preventing damage if leakage occurs.

Perstorp's engineered fluids use a molecular design approach likened to Lego building blocks, allowing tailored viscosity, thermal, safety, and sustainability properties at the molecular level. Working with partners Inventec (ODM) and Intel, they demonstrated that dielectric coolant achieves 1,100W TDP in an unmodified water-based cold plate system. Intel's SuperFluid technology -- using air infusion to inject bubbles into the flow, reducing viscosity and breaking boundary layers -- adds another 10-15% thermal performance improvement. Perstorp has developed a product family with variants for different requirements: lower-viscosity versions for thermal performance, and high-flash-point versions (250C+) for Japanese and Korean regulatory compliance. Material compatibility testing focused on sealing materials (O-rings, QDs) rather than metals, leveraging existing immersion cooling experience where dielectric fluids contact far more diverse materials.