Who makes immersion cooling systems for AI data centers

Immersion cooling replaces the cold-plate-and-manifold chain entirely: instead of routing coolant to each die through a plate, the whole server tray sits in a bath of dielectric fluid that carries heat away by direct contact. Single-phase systems keep the fluid liquid throughout and rely on pumps and heat exchangers to move heat out of the tank; two-phase systems let the fluid boil at the hot surfaces and recondense at a coil, using the phase change itself to move heat more efficiently. It is a different mechanical and facility design from the rack-based direct-to-chip chain used elsewhere in this layer — servers and racks built for immersion need different chassis, connectors, and serviceability approaches, and retrofitting an existing air-cooled or direct-to-chip hall for immersion is a bigger undertaking than adding cold plates. Adoption has concentrated in specific use cases rather than becoming the default alongside direct-to-chip. Investors should watch it as a higher-conviction, narrower bet than direct-to-chip cooling: fewer vendors, less standardization, and adoption tied to specific operators and use cases rather than broad industry uptake.