As server technology continues to press thermal boundaries, maintaining the health of your Thermal Control System (TCS) has become more critical than ever. A key factor in keeping these systems operating at peak performance is accurate testing and best practice management of server coolant. Whether you’re deploying a new system or maintaining an existing one, coolant testing can prevent corrosion, ensure component compatibility, and support long-term system reliability.
TCS COOLANT REQUIREMENTS
Selecting the right coolant is the first step toward ensuring a reliable TCS. Most systems use either treated water or a propylene glycol mix such as PG25, which contains 25% propylene glycol and 75% deionized water. This formulation provides a balance of thermal performance and freeze protection. Inhibitors are also added to the coolant to protect a wide range of metal components, including copper, aluminum, stainless steel, and brass.
Compatibility is key. System designers will perform compatibility or corrosion testing to ensure the coolant won’t react negatively with components such as pumps, valves, heat exchangers, and cold plates. Overlooking these factors can result in premature failures or costly system damage.
CLEANLINESS IS CRITICAL
System cleanliness is the key to successful deployment. Pre-cleaning helps remove incidental manufacturing debris before introducing any fluid into the system. Each component—including the CDU and server racks—should be flushed individually to avoid cross-contamination. Using the CDU to flush the system should be avoided since it can disperse debris and damage internal components.
Flushing should be performed at optimal pressure using non-silicate-based cleaning agents that won’t harm the environment or the TCS. Once the flushing is complete, the system should be filled with heat transfer fluid, being careful to eliminate trapped air. Documenting fluid quality through testing during this stage provides a useful baseline for ongoing monitoring.
FILTRATION: KEEPING FLUIDS CLEAN
Effective filtration is essential to keep coolants free from particulate. Both side stream and inline filtration methods are commonly used in server TCS environments. Inline filtration on the CDU typically uses 25–50-micron filters, while side stream filtration should use filters rated <25 microns.
Filter types include bag filters, spun bonded, pleated, and mesh made from materials such as polypropylene, nylon, or stainless steel. Cotton and polyester should be avoided, since they may release fibers into the system. Routine filter inspection and replacement schedules are essential to avoid pressure drops or fluid contamination.
MAINTENANCE & MONITORING: SUSTAINING SYSTEM HEALTH
Regular coolant testing and fluid analysis are crucial for proactive maintenance. Depending on system complexity and operating conditions, testing should be conducted at least quarterly. Monitoring by a third-party lab will result in the most accurate and detailed diagnostics.
Together, proper coolant testing, commissioning practices, filtration, and monitoring extend the life of the TCS, protecting your substantial investment, and ensuring uninterrupted data center operations.
For an overview on server coolant tests offered by Eurofins TestOil, visit: https://testoil.com/routine-testing/testing-server-coolants-the-key-to-protecting-both-the-equipment-and-your-data/
For more information on working with Eurofins TestOil for coolant analysis, oil analysis or training, fill out the form below; visit https://testoil.com/company/contact-us/; call 216-251-2510; or email sales@testoil.com.
About Eurofins TestOil
With more than 30 years of experience in the oil analysis industry, Eurofins TestOil focuses exclusively on assisting industrial facilities with reducing maintenance costs and avoiding unexpected downtime through oil and fuel analysis program implementation. As industry experts in diagnosing oil-related issues in equipment such as turbines, hydraulics, gearboxes, pumps, compressors and diesel generators, Eurofins TestOil provides customers with same-day turnaround on routine oil analysis testing. For more information on partnering with Eurofins TestOil on oil analysis programs or training opportunities visit https://testoil.com. Contact: Al Yates 216-251-2510; sales@testoil.com.
About Eurofins – the global leader in bio-analysis
Eurofins is Testing for Life. Eurofins is the global leader in food, environment, pharmaceutical and cosmetic product testing, and in discovery pharmacology, forensics, advanced material sciences and agroscience Contract Research services. Eurofins is also a market leader in certain testing and laboratory services for genomics, and in the support of clinical studies, as well as in BioPharma Contract Development and Manufacturing. The Group also has a rapidly developing presence in highly specialised and molecular clinical diagnostic testing and in-vitro diagnostic products.
With over 61,000 staff across a network of 940 laboratories in 59 countries, Eurofins’ companies offer a portfolio of over 200,000 analytical methods. Eurofins Shares are listed on Euronext Paris Stock Exchange.
