Feature Article

Future Trends in Server Room Energy Efficiency – In-Rack CDU (Coolant Distribution Unit) for Liquid Cooling Systems


According to statistics result of comprehensive investigation: the power consumption of data centers is approximately 50 times that compare to general building consumption and among 33% for cooling systems. The 2% of global carbon emissions is from data centers. A key approach to reducing power consumption and improving PUE (Power Usage Effectiveness ) is the adoption of liquid cooling systems, enhancing traditional air-cooling efficiency. Liquid cooling solution can reduce 28% of power consumption, and under the same power consumption, lowers PUE to 1.2 from 1.6 to enhance overall computing efficiency.

Currently, Kaori develops In-Rack CDU (Direct-to-Chip (D2C) Cold Plate In-Rack CDU),  which is capable of 80 kW heat dissipating from the cabinet. This provides an effective cooling solution for high-power processors, simultaneously reducing the overall Power Usage Effectiveness (PUE) of the data center, achieving more efficient computational operations, and reducing environmental energy waste.

KAORI’s D2C Cold Plate Liquid Cooling Solution、CDU product

Utilizing the liquid-to-liquid heat exchange principle, waste heat generated from the server's cold plate loop is transferred to the facility cooling loop for heat exchange. The cooling liquids in these two loops remain separate, preventing mutual contamination. Additionally, waste heat can be reused through recovery equipment. This system significantly reduces overall PUE to below 1.2, decreases power consumption by 20% to 30%, and saves operational costs.


Hot Swappable Pump Coolant Distribution Unit (CDU)

The core component of the CDU is the Brazed Plate Heat Exchanger, with Kaori boasting 30 years of experience as a leading designer and manufacturer of plate heat exchangers in Taiwan. Kaori's CDU utilizes the liquid-to-liquid heat exchange principle, recovering and reusing waste heat from the server while optimizing hot-swappable functionality for maintenance without downtime. The CDU is installed at the bottom of the cabinet, corresponding to the height of four 4U servers.


Rack Manifolds

These rack manifolds are suspended in the rear space of the cabinet, primarily providing cooling liquid circulation to each cold plate on the server, allowing a maximum of 2 cooling loops per 1U server.


Key Advantages of Coolant Distribution Unit (CDU)

  1. Taiwan's Leading Plate Heat Exchanger: Brazed Plate Heat Exchanger serve as the CDU's core component, Kaori’s 30 years of refined technological expertise leading in technology, quality, and market share.
  2. Hot-swappable pump design: Allows quick maintenance without system downtime.
  3. Redundant pump system: Double pumps design enables continuous operation by switching to the other power supply in case of failure.
  4. Temperature control: Built-in proportional valve for precise control of CDU outlet temperature.
  5. Electromechanical control: Provides both manual and automatic control modes.
  6. Stable flow: Maintains stable flow even when any server is removed from the cabinet, unaffected by dismantling.
  7. Condensation warning: Prevents component damage due to low CDU supply temperatures causing server internals to condense.
  8. Leak detection: System detects liquid leaks in both CDU and CDM.
  9. Customized production: Offers tailored recommendations for flow rate, temperature, pipeline design, plate heat exchanger style, etc., creating customized CDU based on customer needs.
  10. Short development cycle: Capable of completing design and providing subsequent maintenance services within 6 months.
  11. In-house production line and integration capabilities: Equipped with advanced electromechanical integration capabilities to meet customer operational requirements.


References article:

AI high-speed computing, data center carbon emissions equivalent to the aviation industry! Expert stock selection strategy keywords: cooling system
When AI servers have higher demand for cooling technology! Why is the trend moving from "air cooling" to "liquid cooling"?


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KAORI’s Liquid Cooling and Immersion Cooling Technologies: High-Performance Server Cooling Capabilities and Competitiveness

Brazed Plate Heat Exchanger Applications for Data Center Cooling


Key word:

Immersion coolingBrazed Plate Heat Exchanger、Cold plate liquid coolingServer cooling