The Key to Efficient Data Center Cooling

The key to efficient data center cooling

August 19, 2025
By Lentus, for the Blue Print

Effective heat management is crucial for maintaining high performance and extending the lifespan of components in data center technology. With the rise of AI and high-performance computing applications, traditional air cooling alone can no longer meet thermal management requirements. In fact, the cost of operating air-cooling systems within datacom equipment cooling systems (DECS) now exceeds the cost of the equipment itself. The industry is now shifting towards liquid and hybrid cooling solutions, such as direct-to-chip liquid cooling (DLC) and air-assisted liquid cooling (AALC) systems.

A propylene glycol-based heat transfer fluid can be used in these systems to provide long-term anti-corrosion and freeze protection.

Properties

This type of heat transfer fluid is often dyed for easy identification and is specifically formulated for liquid-cooled, direct-to-chip applications. It typically comes pre-mixed and should not be diluted below recommended concentrations, as doing so may increase the risk of bacterial contamination. Biostatic formulations help prevent microbial growth and system contamination.

For optimal performance, the fluid should include corrosion inhibitors, pH stabilizers, and buffers, combined with high-purity propylene glycol suitable for sensitive electronic cooling applications. These ingredients provide long-term reliability and protection in liquid-cooled, direct-to-chip data center cooling systems.

Design considerations

These fluids are designed for long-term corrosion protection of common materials used in DECS, including high-copper surface systems, solder, brass, mild steel, cast iron, and aluminum. It is recommended to verify compatibility with any components that will come into direct contact with the fluid at both the minimum and maximum expected operating temperatures. Compatibility should be confirmed with component material suppliers or the original equipment manufacturers (OEMs).

System preparations

In certain applications, it is recommended to flush the pipes of your system to remove loose solids before adding the heat transfer fluid. The system should also be thoroughly drained of any remaining water to prevent unintentional dilution. If any water remains after adding heat transfer fluid, it can inadvertently become over-diluted. This can cause bacterial contamination in the system. Along with an initial flush, there should be bypass filters to collect any solids or particles that form in the fluid.

Fluid testing and maintenance

Many testing resources are available to ensure fluid quality and performance, such as a representative sample, visual inspections, handheld refractometers, handheld pH meters, and reserve alkalinity (RA) tests. These tests help confirm that the system is operating within expected performance parameters and may help minimize unplanned maintenance. When it's time to replace the fluid, it must be fully drained from the system and replaced with new material. That is the only way to remove the harmful impurities or degradation compounds that would cause issues in the system.

Safety note

Users should consult the most recent Safety Data Sheet and operating guidelines for any propylene glycol-based heat transfer fluid prior to use. These documents provide detailed safety, handling, and operational information.

Effective thermal management is increasingly important as data centers evolve. Propylene glycol-based heat transfer fluid is important for liquid-cooled, direct-to-chip systems because it includes features that support corrosion resistance, microbial control, and extended operational reliability.

Content originally from Lentus. Reused here with permission.