Challenge #6: Preventing TCS Contamination in Liquid-Cooled Data Centers
Executive Summary
Schneider Electric's White Paper 210 identifies contamination prevention as one of the eight most critical challenges facing direct liquid cooling (DLC) deployments in data centers. As the IT industry transitions to liquid cooling for extreme chip power densities, the complexity of preventing Technology Cooling System (TCS) contamination has emerged as a significant risk factor for server damage.
The Critical Vulnerability: Cold Plate Microchannels
The core issue stems from the fundamental architecture of direct-to-chip cooling systems. Modern cold plates feature microscopic channels designed to maximize heat transfer efficiency, but this precision engineering creates extreme vulnerability to particulate contamination.
"The isolation function is critical because the IT coolant flows through cold plates in the IT equipment. FWS water carries larger particles than TCS coolant. These cold plates have very small channels that can easily become clogged, placing the chip at risk of overheating and damage, thus requiring very stringent control of the coolant composition."
Filtration Requirements: The 12-20x Difference
The study reveals a striking disparity in filtration requirements between facility-side and technology-side cooling systems. This difference underscores the extreme sensitivity of liquid-cooled IT equipment to contamination.
FWS (Facility Water System)
Filtering particulate size for facility-side cooling infrastructure
TCS (Technology Cooling System)
Required filtering for direct-to-chip liquid cooling systems
This 12-20x difference in filtration requirements reflects the microscopic tolerances of cold plate microchannels. While facility water systems can tolerate particles up to half a millimeter, technology cooling systems demand sub-25-micron cleanliness to prevent channel clogging and surface abrasion.
Material Incompatibility and Debris Generation
Schneider Electric's research emphasizes that contamination isn't just an installation issue—it's an ongoing operational risk driven by material compatibility throughout the entire TCS loop.
"The fluid in this case is the coolant circulated through the server's cold plates. All materials in the CDU, and connectors, seals, piping, valves, and the server's cold plates, in contact with the coolant are known as wetted materials. If these materials are incompatible, corrosion is triggered, eroding materials at different sites of the TCS loop. This creates debris within the coolant, representing a serious risk of damage to the IT equipment. Debris can clog the tiny channels in the cold plates and abrade their surfaces. Corrosion also increases the risk of leaks."
The study identifies seals as part of the critical "wetted materials" category—components that must be carefully specified and controlled to prevent galvanic corrosion and debris generation. Yet industry practice continues to source commodity seals with zero cleanliness verification.
Best Practices from Schneider Electric Research
The white paper provides specific guidance for addressing contamination risks in TCS loop design:
1. Follow Compatible Materials Lists
"Refer to compatible materials lists for TCS wetted materials (including the CDU) provided by IT equipment manufacturers. These guidelines should be strictly followed to prevent technical issues and maintain warranty coverage."
2. Maintain Material Consistency
"Use the same or similar materials throughout the entire TCS loop when possible, to minimize incompatibility. Consider designing separate TCS loops if IT equipment cold plates materials vary."
3. Document All Wetted Materials
"Maintain a registry of all materials used in the TCS loop design, including materials used in the CDUs and IT cold plates. Use this registry as reference for planning installation and maintenance tasks; and update periodically."
4. Leverage Vendor Expertise
"Use your cooling solution provider's expertise to guide the design of your TCS loop if in-house expertise doesn't exist. The vendor's expertise should facilitate a more reliable deployment of liquid cooling in your data center and avoid potential warranty issues from choosing incompatible materials."
The Specification Gap: Where VeriClean Fits
While Schneider Electric's research clearly identifies contamination as a critical challenge and emphasizes the importance of material compatibility, a significant gap remains: no one specifies seal cleanliness.
Mechanical Engineers
Specify material properties (EPDM, FKM, PTFE)
Coolant Chemists
Specify compatibility matrices and formulations
Cleanliness Specs
Surface verification and particle control
VeriClean Seals™ addresses this gap by providing verified surface cleanliness with 70–99% particle reduction* through optical microscopy and laser particle counting. We're not replacing material compatibility specifications—we're adding the missing cleanliness dimension that Schneider Electric's research shows is critical for preventing TCS contamination.
Take Action on Contamination Risk
Download our technical specifications to see how VeriClean seals integrate with your TCS loop material registry and contamination control protocols.
References
[1] Torres Arango, M.A., Avelar, V., Lena, S., McGlocklin, D. (2025). Direct Liquid Cooling System Challenges in Data Centers. Schneider Electric White Paper 210, Version 1.
[2] ASHRAE Technical Committee 9.9. Water-Cooled Servers: Common Designs, Components, and Processes. ASHRAE Datacom Encyclopedia.
[3] Open Compute Project. Guidelines for Using Propylene Glycol-Based Heat Transfer Fluids in Single-Phase Cold Plate-Based Liquid Cooled Racks. OCP Specification.
[4] Pacific Rubber & Packing, Inc. VeriClean Seals™ internal test data. Particle reduction results verified by optical microscopy and laser particle counting. *Results vary by part geometry and material type.