Modular Data Center Liquid Cooling

Modular data center liquid cooling uses liquid-based systems to efficiently remove heat from high-density racks, enabling higher performance, energy efficiency, and scalable deployment.

Overview

Modular data centers integrate liquid cooling systems to manage the intense heat generated by modern CPUs, GPUs, and AI accelerators, which can exceed 100 kW per rack in AI workloads (e.g., Nvidia Blackwell GPUs) . Unlike traditional air cooling, liquid cooling circulates a coolant directly to heat-generating components, offering superior thermal conductivity and enabling higher rack densities without overheating .

Types of Liquid Cooling

1. Direct-to-Chip Cooling (D2C): Cold plates are mounted directly on CPUs, GPUs, or other chips. Coolant flows through these plates, absorbing heat at the source. This method supports high-density racks and reduces thermal resistance, allowing chips to operate at optimal temperatures .
2. Dielectric Direct-on-Chip Cooling (DDoCC): Uses dielectric fluids that are electrically non-conductive, allowing safe contact with electronics. Two-phase dielectric cooling can boil on the chip surface, leveraging latent heat for highly efficient cooling while enabling higher facility water temperatures and energy savings .
3. Rear Door Heat Exchangers (RDHx): Liquid-cooled coils are integrated into the rear doors of racks, removing heat from hot air exiting the servers. This hybrid approach allows incremental adoption of liquid cooling in existing air-cooled data centers .
4. Immersion Cooling: Entire servers are submerged in dielectric fluids, providing uniform cooling and reducing the need for complex airflow management .

Modular Implementation

Modular data centers are designed as self-contained units with integrated cooling, power, and IT infrastructure. Liquid cooling modules can be deployed incrementally, allowing operators to scale capacity without major retrofits. Key components include:

• Coolant Distribution Units (CDUs) to regulate flow and temperature
• Cold plates and manifolds for direct heat transfer
• Heat rejection units to dissipate absorbed heat
• Monitoring and leak detection systems for operational safety

Benefits

• Higher performance: Maintains optimal temperatures for high-power chips, preventing thermal throttling .
• Energy efficiency: Reduces power usage effectiveness (PUE) and allows warmer facility water, lowering chiller energy consumption .
• Scalability: Modular design supports phased deployment and densification of server racks .
• Sustainability: Lower water usage and reduced reliance on air conditioning improve environmental impact .

Operational Considerations

• Continuous operation of pumps and CDUs is critical for AI/HPC workloads due to rapid heat spikes .
• Electrical and mechanical systems must accommodate higher densities, including UPS-backed power for cooling loops and additional cabling for monitoring .
• Retrofitting existing air-cooled facilities requires careful planning for piping, CDU placement, and integration with legacy infrastructure . In summary, modular liquid cooling transforms data center design by enabling high-density, energy-efficient, and scalable operations, particularly for AI and HPC workloads, while offering flexibility for both new builds and retrofits.