Liquid-cooled distribution box

A liquid-cooled distribution box, often called a Coolant Distribution Unit (CDU) or manifold, manages and delivers coolant to high-density IT racks, ensuring efficient heat removal and precise temperature control.

Function and Purpose

A liquid-cooled distribution box is designed to distribute coolant from a central source to servers or racks, enabling direct-to-chip or rear-door cooling in high-density data centers. It regulates flow, pressure, and temperature to ensure even heat dissipation across all servers, preventing hotspots and improving overall energy efficiency and performance . These units are essential for AI workloads, GPU servers, and HPC environments where traditional air cooling is insufficient .

Design and Components

• Manifolds and Piping: Typically made from stainless steel (e.g., 304 grade) with pipe diameters ranging from 25mm to 400mm, manifolds distribute coolant evenly to multiple racks .
• Valves: Isolation and flow-control valves, either electronic or autoflow, allow precise regulation of coolant delivery .
• Pumps and Redundancy: Many CDUs include redundant pumps to ensure continuous operation and prevent downtime .
• Filtration and Monitoring: Built-in filtration and sensors monitor temperature, pressure, and flow, often with remote monitoring via SNMP, Modbus, or HTTP interfaces .

Types and Configurations

• In-Rack CDUs: Compact units installed directly in server racks, often modular for scalability and maintenance .
• In-Row CDUs: Positioned between racks to serve multiple units, supporting high heat loads up to several megawatts .
• Manifold-Based Systems: Distribute coolant to multiple racks or servers, compatible with hybrid air-and-liquid deployments .

Applications

• High-Density Data Centers: Supports racks with high power density, including AI and GPU servers .
• Direct-to-Chip Cooling: Enables efficient heat removal from CPUs and GPUs using coldplates or rear-door heat exchangers .
• Scalable Deployments: Systems can be scaled from a single rack to multi-megawatt facilities, supporting sustainable heat reuse .

Advantages

• Efficient Heat Management: Reduces thermal hotspots and improves server performance.
• Energy Savings: Liquid cooling is more efficient than air cooling for high-density racks.
• Flexibility: Compatible with various cooling liquids, rack types, and hybrid cooling strategies .
• Reliability: Redundant pumps, precise flow control, and monitoring ensure continuous operation . In summary, a liquid-cooled distribution box is a critical component in modern data centers, enabling high-performance, energy-efficient, and scalable cooling for dense IT environments, particularly for AI, HPC, and GPU-intensive workloads. It integrates seamlessly with existing infrastructure and supports both direct-to-chip and rear-door cooling strategies.