What Is Liquid Cooling in Data Centers?
9.17.2026
Artificial intelligence and high-performance computing are changing how data centers manage heat. As CPUs and GPUs become more powerful and rack densities increase, traditional air cooling can become less practical for removing concentrated heat loads.
Liquid cooling in data centers is a method of removing heat from servers using a circulating coolant instead of relying primarily on air and fans. Because liquid can transport heat efficiently, it allows cooling systems to capture heat closer to high-power components such as CPUs and GPUs.
How Does Liquid Cooling Work in a Data Center?
One of the most common approaches is direct-to-chip cooling.
In a direct-to-chip system, a metal cold plate is mounted directly to a CPU, GPU or other high-heat component. Coolant flows through sealed channels inside the cold plate, absorbs heat from the processor and carries it away from the server.
The warmed coolant then travels through the cooling loop to a coolant distribution unit (CDU). Pumps maintain the required flow through the system, while a heat exchanger within the CDU transfers heat from the server-side cooling loop to the facility cooling system.
From there, the heat can be rejected through equipment such as chillers, dry coolers or cooling towers before cooled liquid is circulated back through the system.
In simple terms:
CPU/GPU → cold plate → coolant → CDU/heat exchanger → facility cooling system
What Are the Main Types of Data Center Liquid Cooling?
Direct-to-Chip Cooling
Direct-to-chip cooling uses cold plates attached directly to high-heat components such as CPUs and GPUs. Coolant circulates through the cold plates without normally coming into contact with the electronics themselves.
This approach is particularly relevant for high-density AI and high-performance computing environments.
Immersion Cooling
With immersion cooling, servers or components are submerged in a specially designed dielectric fluid that does not conduct electricity. The fluid absorbs heat directly from the hardware before transferring it to the cooling system.
Hybrid Cooling
Liquid cooling does not necessarily eliminate air cooling. Many data centers use a hybrid cooling approach, where liquid handles the highest heat loads while air continues to cool components that are not connected to the liquid loop.
Why Is Liquid Cooling Important for AI Data Centers?
AI workloads rely heavily on powerful GPUs and other processors that can generate significant amounts of heat in a relatively small space.
As more computing power is concentrated within each rack, moving enough air through the equipment becomes increasingly challenging. Liquid cooling captures heat closer to where it is generated, helping data centers accommodate higher-density computing environments.
Depending on the overall system design, liquid cooling can also reduce reliance on server fans and create opportunities for more efficient thermal management.
What Role Do Pumps and CDUs Play in Liquid Cooling?
Reliable coolant circulation is essential to the liquid cooling process.
Pumps move coolant between servers, CDUs, heat exchangers and facility cooling equipment. The CDU helps manage flow, pressure and temperature while transferring heat between the technology cooling system and the facility water system.
For mission-critical data centers, pump selection, controls, monitoring and redundancy are important considerations when designing the complete cooling system.
Wilo USA provides pumps and pump systems for data center cooling applications, supporting circulation throughout direct-to-chip cooling, CDU, chiller and facility cooling-water systems.
As AI and high-performance computing continue to increase data center heat loads, efficient and reliable coolant circulation will remain an important part of keeping critical infrastructure operating.
Does Liquid Cooling Mean Water Touches the Electronics?
Usually, no.
In direct-to-chip systems, coolant remains contained inside sealed cold plates, tubing and manifolds. Immersion cooling is different because the hardware is intentionally surrounded by a specially selected dielectric fluid.
Ultimately, liquid cooling is a heat-transport system: cold plates or dielectric fluids capture heat, pumps circulate the coolant, CDUs transfer heat between cooling loops, and the facility cooling system removes that heat from the data center.
Wilo Data Center Solutions
As data center heat densities increase, selecting the right cooling architecture and the pumps that support it is critical to maintaining reliable thermal performance. Wilo USA offers mission-critical rated pump solutions designed to support liquid cooling and facility cooling systems.