AI Server Liquid Cooling Basics
As AI rack densities climb beyond the limits of air cooling, data centers are turning to liquid cooling to remove heat from high-density GPU racks. Building on four decades of industrial fluid expertise, HLJH supplies AI server cooling fluids across Taiwan and the Asia-Pacific region, using the two mainstream approaches: direct-to-chip (cold plate) cooling and single-phase immersion.
Direct-to-Chip Coolant (PG25)
PG25 is a water-propylene glycol heat-transfer fluid for direct-to-chip (cold plate) cooling of high-heat components such as CPUs and GPUs. It ships ready to use with no dilution, is engineered for material compatibility in line with Open Compute Project (OCP) guidelines, and is recyclable at end of life. PG25 is available to order with a lead time of about one month, and cooling performance is verified against each facility's rack configuration and operating conditions.
Immersion Cooling Fluid (Still in Validation)
The single-phase immersion fluid is a non-conductive dielectric coolant for fully submerged systems. Immersion cooling is an emerging approach that is still in the validation stage and not yet a mature, off-the-shelf product. HLJH offers it through a joint testing and evaluation program rather than as a stocked item, and does not publish fixed specifications or delivery commitments for immersion at this stage. If immersion is on your roadmap, we can plan a pilot evaluation.
Joint Testing and Validation: Because cooling performance depends heavily on each facility's rack design and thermal architecture, We runs joint validation programs with operators, system integrators, and server makers, testing fluid performance under real operating conditions. Support includes evaluation planning, materials-compatibility assessment, and fluid analysis.
Frequently Asked Questions (FAQ)
Q1: Can I order the direct-to-chip coolant (PG25), and what is the lead time?
A: Yes. PG25 is available to order with a lead time of about one month. It is a water-propylene glycol fluid, ready to use with no dilution, and designed for material compatibility in line with OCP guidelines. Share your rack configuration and required volume for a quotation.
Q2: Immersion or direct-to-chip, which should I choose?
A: Direct-to-chip (cold plate) loops using PG25 are often easier to adopt in existing facilities; single-phase immersion suits purpose-built high-density deployments and is still maturing. Tell us your facility design and rack density and we advise.
Last Updated: 2026-09-09