HPC budgets are won and lost on the energy bill, and the peer-reviewed verdict is in: direct-to-chip liquid cooling cuts total facility power by up to 14.4% depending on inlet temperature. Adoption is still early — Omdia counted only about 19% of data centres running liquid in 2024, with another 36% planning it — which is exactly why the window matters. Equipment demand jumped from roughly $1.3B in 2024 to $2.2B in 2025, up 68.2% in a year, and the machines setting the Green500 efficiency leaderboard — including 30 MW-class exascale builds — run warm-water direct-to-chip loops as standard. RackForge builds the rack half of that loop: manifolds above both door lines, UQD pairs at fixed coordinates, 25–80 L/min on PG25, pressure-proven at 1.5× for 24 hours before the crate closes.
Request a Quotation Air vs Warm Water, in Numbers
−14.4% facility power · 19% → 36% adoption · 25–80 L/min on PG25
Seven rows that decide how a research computing budget spends the next decade. The left column is the air tradition; the right column is where the efficiency rankings and the equipment orders have already moved.
| Thermal strategy | Air-cooled HPC hall | Warm-water liquid-cooled row |
|---|---|---|
| Heat removal path | Air CRAC volume flow plus rear-door exchangers at best | Water Direct-to-chip warm water, manifolds factory-fitted above the doors |
| Facility energy | Air The baseline every grant application now apologizes for | Water Up to −14.4% total facility power, peer-reviewed, by inlet temperature |
| Density ceiling | Air Saturates around the 40 kW-class rack | Water 40–132 kW liquid envelope per cabinet on the RF-LC frame |
| Chiller dependence | Air Mechanical chilling most hours of the year | Water 45°C warm water benchmark — a chiller-free operating envelope |
| Adoption curve | Air The 81% majority, aging toward retrofit | Water 19% deployed in 2024, 36% more planning; AI-server attach 14% → 22% by 2026 |
| Equipment demand | Air Flat, replacement-rate spending | Water $1.3B (2024) → $2.2B (2025), up 68.2% year on year |
| Where the flagships are | Air Outside the top efficiency rankings | Water Green500 leaders and 30 MW-class exascale machines run warm-water loops |
A direct-to-chip deployment fails at its fittings far more often than at its science. RackForge builds the rack-side metre in the factory, to a drawing, under a pressure test — so the facility team connects headers to ready hardware instead of inventing an interface in the room.
Example SKU RF-LC-48U on an 800 × 1200 mm frame; 52U builds (2461 mm / 96.9 in) quoted for maximum-density rows. CDU heat-capture classes below are design alignment benchmarks drawn from published direct-to-chip system data, not capacity claims.
| Parameter | RF-LC Specification · HPC build |
|---|---|
| Design flow | 25–80 L/min per rack, balanced per branch |
| Working fluid | PG25 — 25% propylene glycol / water |
| Quick disconnects | UQD pairs, OCP-aligned interface, drip-less, capped and tagged |
| Manifold routing | above front and rear doors, drilled to approved drawing |
| Branch bore | DN50 rack manifolds · DN100–DN150 row headers, design alignment |
| Warm-water benchmark | 45°C facility water — chiller-free operating envelope |
| Power envelope per cabinet | 40–132 kW, liquid builds |
| Static load | 1,600 kg · 4× safety factor · 72 h hold with creep recheck |
| Width × depth | 800 × 1200 mm · 52U height 2461 mm / 96.9 in optional |
| Pressure proof | 1.5× working pressure · 24 h hold · zero-drop record shipped |
| Leak detection | drip pans standard · per-rack leak-sensing rope optional |
| Grounding | manifold-to-frame bonding ≤0.1 Ω |
| Doors | front mesh ≥80% open area · glass front option for lab tours |
| Standards | EIA-310-E · IEC 60297 · CE (EN IEC 62368-1) · RoHS |
The liquid frame, its high-density sibling and the cable hardware that keeps 132 kW cabinets serviceable.
The full hydraulic specification: manifolds, UQD pairs and drip pans pre-installed, 1.5×/24 h pressure proof, 25–80 L/min on PG25.
For the air-cooled end of the machine room: 1,600 kg frames, busbar-slot columns and NVL72-class footprint alignment up to the 40 kW air limit.
Vertical PDU mounts, lacing bars, overhead trough brackets and grounding kits — the unglamorous hardware that keeps a liquid row maintainable between flushes.
−14.4% facility power · 1.5×/24 h pressure proof · 25–80 L/min · MOQ 5
48-hour engineering reply · MOQ from 5 cabinets · FOB / CIF / DDP