Trade-Offs Between Single-Phase And Two-Phase Liquid Cooling - Presented By Coolit Systems

Reza Najjari (Thermal Mechanical Engineering Manager) - Coolit Systems With the growth of AI- liquid cooling of IT equipment is no longer optional. Power consumption and heat dissipation have dramatically increased. Liquid cooling is now required to manage heat loads of AI semiconductors with much higher heat fluxes and AI servers with much greater rack densities. There are two core approaches to liquid cooling: single-phase using water or a water-glycol mixture as a coolant and two-phase using refrigerants. In single-phase cooling- the coolant remains in the liquid state- whereas in two-phase cooling- the refrigerant changes between liquid and gas phases. We will provide an assessment of single-phase and two-phase direct liquid cooling (DLC) technologies- focusing on system design and operational differences. These differences help explain why single-phase DLC is a mature technology now seeing mainstream adoption. In contrast- two-phase DLC is earlier in the technology adoption cycle and still faces technical and operational hurdles.