Coolant Distribution Unit (CDU)

What Is a Coolant Distribution Unit?

A coolant distribution unit (CDU) is a key component in data center liquid cooling systems. It is responsible for managing and circulating the coolant to maintain optimal server temperatures and ensure efficient, reliable operation.

How Does a CDU Work?

Coolant distribution units act as central control points for liquid coolant, pumping from a central supply to racks (and backs) of IT equipment. The equipment in data centers generates a significant amount of heat and requires a constant source of cooling to minimize the risk of overheating. Here is a breakdown of how this cooling system for data centers works:

• Heat Removal: Instead of using air conditioning alone, liquid cooling systems, with the CDU at the center, can be used to remove heat more efficiently.
• Coolant Circulation: The CDU circulates a coolant (typically water or a specialized fluid) through a closed-loop system. This coolant absorbs heat from the IT equipment.
• Heat Exchange: The heated coolant returns to the CDU, where the heat is transferred to another cooling loop or a facility's cooling system. This transfer often happens through a heat exchanger within the CDU.
• Temperature Control: The CDU carefully controls the temperature and flow rate of the coolant to ensure that the IT equipment stays within its optimal operating range.
• Monitoring and Management: CDUs are equipped with sensors and controls to monitor the coolant's temperature, pressure, and flow. This allows data center operators to optimize cooling performance and detect potential problems.

You may hear about direct-to-chip liquid cooling, which uses specially designed plates (“cold plates”) that sit on top of the chips (like CPUs or GPUs). The liquid coolant flows through these plates, absorbing heat directly from the hardware.

What Are the Benefits of Liquid Cooling CDUs?

In the world of hyperscale and colocation data centers, energy efficiency and reliability are the keys to improving their sustainability. Large data centers using inefficient air-cooled systems tax the power grid and suffer from less precise control over the temperature within the racks. Direct-to-chip liquid cooling is optimized for high-density data centers and ensures efficient heat transfer directly from the IT racks. Other benefits include:

• Reliability: CDUs are designed with redundant parts to reduce the risk of leaks and downtime.
• Monitoring: Most CDUs have built-in sensors and monitoring systems to detect leaks or problems early.
• Scalability: CDUs can be scaled to meet the changing cooling needs of a data center.
• Adaptability: They can use different types of coolants and work with various data center setups, making them versatile options.

Resources for Coolant Distribution Units

• Trane CDU - Coolant Distribution Unit
• Trane Expands Thermal Management System Capabilities
• Improving data center design, development and operation

If you're interested in learning how coolant distribution units can make your data center a more efficient, more sustainable operation, contact your local Trane expert today.