How does liquid cooling in a CDU improve data center efficiency?

By Cory Marcon, Power & Energy Industry Marketing Manager, Endress+Hauser USA 

Artificial intelligence, machine learning and high-performance computing are pushing the thermal limits of data centers. Modern GPUs and accelerators offer high compute density but generate more heat than traditional air-cooling systems can efficiently manage.

As operators adopt liquid-cooled architectures, cooling systems are becoming more complex and require precise measurement and control. Reliable instrumentation for temperature, flow, pressure and water quality, such as Endress+Hauser’s sensors and digital diagnostics, is essential for improving efficiency, protecting infrastructure and supporting sustainable data center growth.

Traditional air cooling moves large volumes of cooled air across servers to remove heat, but this method becomes less efficient as rack densities increase. High-power AI servers produce more heat than air can remove without excessive airflow and energy use.

Liquid cooling is more efficient because water’s higher heat capacity allows heat to be removed closer to the source. High-accuracy temperature and flow measurement, such as Endress+Hauser temperature sensors and electromagnetic flowmeters, help operators maintain optimal cooling setpoints and reduce energy waste.

A key advancement is direct-to-chip liquid cooling, which delivers coolant directly to CPUs and GPUs to minimize thermal resistance. Rear-door heat exchangers and immersion cooling are also used in high-density environments.

As these systems become more process-driven, operators rely on industrial-grade instrumentation for temperature, pressure and flow measurement to maintain stability and performance. Endress+Hauser instrumentation provides reliable data for both primary and secondary cooling loops.

Water serves as a heat transfer medium in closed-loop liquid-cooling systems, circulating through servers, cooling distribution units and heat exchangers. Heat absorbed in the data hall is then transferred to facility-level systems such as chillers or cooling towers. 

To protect cooling loops, data centers monitor water quality with liquid analysis instrumentation. Sensors for conductivity, pH and turbidity, such as Endress+Hauser’s Memosens digital sensors, verify water treatment and help prevent corrosion or fouling.

Water use is a growing sustainability challenge, commonly measured by water-use efficiency (WUE). Inefficient cooling increases both water and energy consumption, amplifying environmental impact.

Accurate flow, temperature and water quality monitoring enables operators to optimize cooling and minimize waste. Endress+Hauser instrumentation delivers real-time data to balance efficiency, reliability and responsible water use.

Cooling distribution units improve efficiency by precisely controlling coolant flow, pressure and temperature at the rack level. This localized approach reduces reliance on centralized air handling and improves thermal stability for high-density AI workloads.

Within CDUs, flowmeters, pressure transmitters and temperature sensors ensure balanced cooling across circuits. Accurate instrumentation allows operators to fine-tune pump operation, reduce energy use and maintain consistent performance.

Modern CDUs increasingly use digital instrumentation with built-in diagnostics, providing continuous insight into coolant flow, pressure, temperature and water quality.

Technologies such as Endress+Hauser's Heartbeat Technology verification and Memosens digital communication support predictive maintenance by detecting issues like blockages or water quality degradation before they affect uptime or damage hardware.

Best practices include adopting liquid cooling for high-density environments, using high-accuracy measurement to maintain optimal thermal setpoints and continuously monitoring water quality to protect cooling loops.

Non-invasive temperature measurement solutions, such as Endress+Hauser's temperature sensors, help reduce leaks, contamination risk and pressure loss. Comprehensive flow and liquid analysis measurement ensures long-term efficiency and reliability as facilities scale.

To learn more about industrial instrumentation for data centers or to speak with an Endress+Hauser expert, click here.