What Is Direct Liquid Cooling (DLC)?_
Direct liquid cooling is a thermal management method where liquid coolant flows through cold plates mounted directly on heat-generating components (GPUs, CPUs). DLC removes heat at the source with 3,500x the thermal capacity of air per unit volume. It is mandatory for NVIDIA GB200 and GB300 NVL72 systems and increasingly common for H100/H200 deployments at high density.
Technical Details
DLC systems circulate a coolant (typically propylene glycol/water mixture) through cold plates that make direct contact with GPU and CPU dies via thermal interface material (TIM). The heated coolant flows through manifolds to a coolant distribution unit (CDU), which transfers heat to the facility water loop. Key components include cold plates (machined copper or aluminum with internal microchannels), manifolds (distributing coolant to multiple cold plates within a node), quick-disconnect fittings (enabling component replacement without draining the loop), leak detection systems (drip sensors and zone-based monitoring), and CDUs (heat exchangers between server-side and facility-side loops). DLC can remove 120+ kW per rack, making it the only viable cooling option for NVL72 systems.
How Leviathan Systems Works with Direct Liquid Cooling (DLC)
Leviathan Systems integrates direct liquid cooling infrastructure as part of GPU deployments, including CDU installation, manifold connection, leak testing, and thermal validation during commissioning.