What is liquid cooling for data centres?

Liquid cooling pipes coolant directly to the chips instead of blowing air over them. It removes 5-10x more heat per rack than air cooling. Two primary methods exist: direct-to-chip liquid cooling (DLC), where cold plates mounted on CPUs and GPUs circulate coolant to absorb heat at the source; and immersion cooling, where entire servers are submerged in non-conductive fluid. DLC supports rack densities of 80-150+ kW (vs 15-20 kW with air) and achieves PUE of 1.1-1.3. Immersion cooling pushes this further to 100-250+ kW per rack equivalent and PUE of 1.02-1.10. Liquid cooling has become essential for AI workloads using NVIDIA H100/H200 and Blackwell GPUs, which generate far more heat than traditional air cooling can handle. The market is projected to reach $32 billion by 2028.