Data center coolants: ThermaGraph™ graphene cooling fluids

ThermaGraph™ is our line of graphene coolants for data center cooling. Each product is graphene at a low loading, 0.05–0.20 wt%, in a carrier fluid matched to how your servers are cooled: ThermaGraph™ in deionized water, a liquid cooling fluid for data centers running indoor closed loops, and ThermaGraph-D™ in white mineral oil, a graphene immersion cooling fluid for single-phase tanks. For the basics of the material, see what is graphene.

It's for data center operators, cooling engineers and integrators who want to test a new fill in a system they already run, using their own baseline data. Patent pending. Made in the USA in Charlotte, NC.

Patent pendingMade in the USA0.05–0.20 wt% grapheneClosed loop + immersion

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ThermaGraph™ works on the fluid side. It doesn't change your hardware. It replaces the liquid that carries heat away from it. In a liquid-cooled data center, heat moves from the chip into a cold plate or an immersion tank, into the coolant, through a coolant distribution unit (CDU) or heat exchanger, and out to the facility water and heat-rejection plant. Our products go into the part of that path closest to the servers.

Water loops: CDU, direct-to-chip and rear-door heat exchangers

Use ThermaGraph™, graphene in deionized water. It's for indoor, conditioned technology cooling loops in closed copper systems where freeze protection isn't specified. If the loop holds glycol, it's drained first. ThermaGraph™ is a new fill, not a top-off.

Single-phase immersion tanks

Use ThermaGraph-D™, graphene in Drakeol white mineral oil, formulated as a dielectric for boards that sit directly in the fluid.

Not a fit for ThermaGraph™ today

Loops that need freeze protection (they should stay on a glycol fluid), outdoor or unconditioned loops, and two-phase boiling systems, which need a different product discussion and a different TDS.

Coatings are a different approach

Some cooling products work on surfaces instead, as coatings on coils, cold plates or heat exchangers. ThermaGraph™ isn't a coating and doesn't treat surfaces. It changes the fluid inside the equipment you already run.

New to these terms? See the cooling glossary below, or read Graphene coolants for AI data centers: what lab tests show and what they don't.

A graphene nanofluid in deionized water, with no glycol, for indoor CDU, direct-to-chip (D2C) and rear-door loops. Same copper, same pumps, new fill.

Carrier

Deionized water. No glycol and no freeze package.

Graphene loading

0.05–0.20 wt%, stated on the certificate of analysis (COA). It's kept low on purpose, because sludge isn't a feature.

Heat transfer

+6% to +18% higher convective heat transfer coefficient (HTC) than a glycol baseline, in our internal pumped-loop tests.

Thermal conductivity

Measured against DowFrost LC25 on the signed lab sheet. Water's thermal conductivity is already above LC25's; the graphene is additional.

Where it fits

Indoor, conditioned technology cooling systems (TCS/DECS) only, in closed copper loops where freeze protection isn't specified. Its freeze point is 0 °C.

What it isn't

Not a freeze fluid, not a dielectric and not a top-off. It's electrically conductive, so never use it to immerse live boards. If your loop holds inhibited propylene glycol such as DowFrost LC25, drain it first.

Materials

Corrosion coupons go in with every pilot. It isn't a substitute for LC25's inhibitor package until the coupon results come back.

ThermaGraph™ vs. DowFrost LC25

DowFrost LC25 values are Dow published data. ThermaGraph™ values come from our internal tests and aren't a specification until the signed lab sheet.

A graphene-enhanced dielectric for single-phase immersion, where the boards sit directly in the fluid. The carrier is Drakeol white mineral oil (CAS 8042-47-5). It's made for tanks, not glycol loops or cold plates.

Carrier

Drakeol white mineral oil, CAS 8042-47-5. Not water, not glycol. The grade is selected per order (typically Drakeol 10 NF through Drakeol 35 USP) and shown on the COA.

Graphene loading

0.05–0.20 wt%, stated on the COA. Low enough to protect pumps, filters and breakdown voltage (BDV).

Electrical

Formulated as a dielectric. BDV and conductivity are reported on the signed technical data sheet (TDS) for each lot. Don't energize boards until the lot's electricals are on the signed sheet.

Heat transfer

Measured against the unfilled dielectric on the signed lab sheet, at the same temperature with the same method.

Viscosity and flash point

Lot-specific. Mineral-oil grades are typically thicker than Castrol ON DC 15 (7.5 cSt at 40 °C). Drakeol 35 has a flash point (COC) of about 240 °C.

Stability

Months of visible suspension. Particle count and filter ΔP are tracked in the 30-day protocol.

Materials

Coupons (copper, soldermask and elastomers) go in with every pilot.

Where it fits

Single-phase tanks for HPC, edge and immersed servers, where ΔT is the constraint. Two-phase boiling systems need a different product discussion and a different TDS.

ThermaGraph-D™ vs. Castrol ON DC 15 / DC 20

Castrol ON values are Castrol published data (conductivity in pS/m). Drakeol is a Calumet / Penreco trademark, named here as the carrier. ThermaGraph-D™ values aren't a specification until the signed lab sheet.

Short, plain-English explainers on how data centers work and how they are cooled. Pick an episode to play it here; the next one starts automatically. Episode 8 covers what graphene is and why it matters for cooling.

Short definitions of the terms used on this page.

CDU (coolant distribution unit)

Pumps, controls and a heat exchanger that separate the liquid loop serving the IT equipment from the facility water, and set its flow and temperature.

TCS (technology cooling system)

The liquid loop between the CDU and the IT equipment: cold plates, manifolds and rear-door coils.

Facility water

The building-side loop that takes heat from the CDUs to chillers, dry coolers or cooling towers.

Direct-to-chip (D2C)

Cold plates mounted on processors and other hot components, with coolant flowing through them.

Rear-door heat exchanger

A liquid-cooled coil on the back of a rack. Server exhaust air passes through it and the liquid carries the heat away.

Single-phase immersion

Servers submerged in a dielectric liquid that stays liquid while it carries heat to a heat exchanger.

Two-phase immersion

A fluid that boils on hot components and condenses above them. It is a different system from single-phase immersion.

PG25

A mix of 25% propylene glycol and 75% water, often with corrosion inhibitors, used where a loop needs freeze protection.

Thermal conductivity (k)

How well a fluid conducts heat when it is not moving, in W/m·K. It is a property of the fluid alone.

Heat transfer coefficient (HTC)

How much heat moves between a surface and a flowing fluid, per unit area and per degree of temperature difference, in W/m²·K. It depends on the fluid, the flow and the geometry, so it is measured in a pumped loop.

ΔT

A temperature difference, for example between the coolant entering and leaving a cold plate.

PUE (power usage effectiveness)

Total facility energy divided by the energy used by the IT equipment. A lower number means less overhead for cooling and power.

BDV (breakdown voltage)

The voltage at which a dielectric fluid stops insulating. It matters for immersion fluids that touch live boards.

wt%

Percent by weight. ThermaGraph™ fluids carry 0.05–0.20 wt% graphene.

COA and TDS

The certificate of analysis (measured values for a specific lot, including graphene loading) and the technical data sheet.

Corrosion coupon

A small metal or material sample placed in the loop or tank during a pilot and inspected afterward for corrosion or attack.