Royal from TCT (Thermal Control Technology) presented a technical analysis of water-based coolants for ICT liquid cooling systems at OCP Global Summit 2025, advocating for pure water coolant over formulated alternatives. The presentation compared the two technology routes across material compatibility, system cleanliness requirements, maintenance burden, and real-time monitoring capability. TCT introduced their medium purification module (MPM) as the key enabling technology and presented a five-year China verification project demonstrating pure water coolant's viability. TCT concluded that pure water coolant is the best choice for MLCP and all ICT liquid cooling systems due to its subtractive control model, interoperability, cost efficiency, and simpler operations.

Key Takeaways

• Water-based coolants split into two routes: pure water coolant (controlled via medium purification module/MPM) and formulated coolant (controlled via proprietary chemical additives); the fundamental difference is how each addresses corrosion and microbial inhibition.
• Pure water coolant enables interoperability — products from different manufacturers can be mixed — while each vendor's formulated coolant formula is proprietary and incompatible with others.
• Pure water coolant provides real-time quality monitoring through conductivity, pH, and dissolved oxygen sensors; formulated coolant cannot be assessed in real-time and requires periodic laboratory sampling.
• Formulated coolant failure in customer deployments caused severe maintenance burdens — TCT documented cases requiring one to two weeks per system to clean, with issues including aluminum and copper oxidation, microbial mud blockage, and seal aging.
• Ion polishing (MPM) is TCT's preferred purification method for conductivity control: cheap, small, zero wastewater, zero electrical energy, 1–5 year lifespan; compared to RO (5–20% water waste, 8–12 kW/MW) and EDI (3 kW/MW, 10-year lifespan).
• TCT's five-year China verification project (Core Switch Server Liquid Cooling System, July 2018 – June 2023) showed pure water coolant maintained conductivity of 6.71 µS/cm, pH of 6.7, turbidity of 0.0 NTU, with no microbial pipeline attachment and only one MPM replacement required.
• Pure water coolant is a 'subtractive control' system (removes contaminants); formulated coolant is an 'additive control' system (replenishes inhibitors); TCT believes pure water coolant is the best choice for MLCP (Modular Liquid Cooling Platform).