What Is Propylene Glycol Coolant?_
Propylene glycol coolant is a mixture of propylene glycol and water (typically deionized water) that circulates through liquid cooling systems to absorb heat from GPU modules and transport it to heat rejection equipment. It is preferred over ethylene glycol in many data center applications due to its lower toxicity, making it safer for personnel in case of leaks or maintenance. The coolant’s thermal properties, such as specific heat and viscosity, are selected per the system design to balance heat transfer efficiency with pump power requirements.
Technical Details
The coolant mixture ratio (commonly 30% propylene glycol to 70% water) is chosen based on the required freeze protection for the facility’s climate, as specified by the OEM or system integrator. Propylene glycol reduces the fluid’s thermal conductivity compared to pure water, so system designers must account for this when sizing pumps and heat exchangers. The coolant must be periodically tested for pH, conductivity, and glycol concentration to prevent degradation or microbial growth. In GPU direct-to-chip or immersion cooling, the coolant must be non-conductive or have very low conductivity to avoid short circuits, though propylene glycol mixtures are typically conductive and require careful electrical isolation.
How Leviathan Systems Works with Propylene Glycol Coolant
During Leviathan Systems field deployments, we fill and bleed the liquid cooling loops with pre-mixed propylene glycol coolant, verifying concentration with a refractometer before commissioning. We also label each rack’s coolant type and ratio on the service panel for future maintenance crews.
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Liquid Cooling Services →