Liquid Cooling Options: RDHx, Direct-to-Chip, Immersion
Data Center Knowledge, Tuesday, August 25th, 2026
Three liquid cooling approaches address AI rack densities that have moved well past air cooling limits.
As AI workloads push rack densities from 5-10 kW to 30-60 kW and beyond, data centers are turning to liquid cooling for its superior heat transfer.
RDHx retrofits existing racks by replacing rear doors with liquid-cooled coils, offering simplicity at moderate efficiency. Direct-to-chip mounts cold plates on CPUs and GPUs, capturing 70-90% of rack heat at the source.
Immersion submerges entire servers in dielectric fluid, enabling extreme density but requiring specialized hardware and operational change. Each approach trades off differently on implementation cost, efficiency, density, and complexity.