⚠ Disclaimer: This section may contain incomplete, out of date, or inaccurate entries. It is AI-maintained on a best-effort basis. Do not rely on it as a sole source — verify claims independently using the source materials listed in individual entries.
Overview
The shift from air to liquid cooling is the defining infrastructure transition of the AI datacenter era. Traditional air cooling hits practical limits at approximately 15–20 kW per rack; NVIDIA’s current H100 and GB200 GPU clusters require 40–120 kW per rack. This density gap is forcing operators to adopt liquid cooling at scale — a transition that is technically straightforward but operationally and organizationally disruptive for facilities built around air. The cooling supply chain is fragmenting into specialists at each layer: dielectric fluid makers, immersion tank manufacturers, cold plate fabricators, CDU (cooling distribution unit) providers, and systems integrators who tie the facility-side water loop to the IT equipment.
Key Themes
- Air cooling ceiling at ~15–20 kW/rack makes it inadequate for dense GPU clusters without liquid augmentation
- Three primary liquid approaches: immersion (servers submerged in dielectric fluid), direct-to-chip (cold plates on CPUs/GPUs, air handles the rest), rear-door heat exchangers (liquid cools rack exhaust air — lowest disruption to existing IT)
- Immersion cooling enables the lowest PUE (<1.03 theoretical) and highest density but requires purpose-built tanks and fluid management — operationally incompatible with standard rack-based tooling and robot-servicing approaches without redesigned hardware (see robotics-automation section)
- Direct-to-chip is the near-term pragmatic solution for AI clusters: NVIDIA’s NVLink rack reference designs, NVIDIA GB200 NVL72, and AMD MI300X all ship with liquid-cooled reference designs; standard CDU + manifold approach fits existing facility water infrastructure
- Waste heat reuse (ERE metric) increasingly economically relevant: liquid cooling return temperatures of 40–60°C can supply district heating or industrial processes; some European operators monetizing this
- Dielectric fluid supply chain: engineered fluids (3M Novec — discontinued, creating supply chain disruption; Engineered Fluids’ BitCool; Shell Immersion Cooling Fluid; Submer’s SmartCoolant) are a critical dependency for single-phase immersion
Companies
Startups & Development Partners
| Company | HQ | Stage | Mission |
|---|---|---|---|
| Submer | Barcelona, Spain | Series B | Single-phase immersion cooling tanks and SmartCoolant fluid; ADA autonomous robot for immersion tank servicing; deployed at HPC and AI facilities globally. |
| LiquidStack | Dallas, TX, USA | Series B | Two-phase immersion cooling (liquid boils, vapor condenses, no pump required for fluid circulation); acquired from Allied Control (formerly HKUST spinout). |
| Iceotope | Sheffield, UK | Series B | Chassis-level precision immersion cooling (“liquid-blanketed” approach — fluid circulates around individual servers without full tank immersion). |
| GRC (Green Revolution Cooling) | Austin, TX, USA | Growth | Single-phase immersion (CarnotJet system); pioneered immersion at scale; long deployment history at HPC and crypto mining facilities. |
| CoolIT Systems | Calgary, Canada | Growth | Direct-to-chip liquid cooling; Rack DCLC system; OEM partnerships with Dell, Lenovo, HPE; widely deployed in HPC. |
| Asetek | Aalborg, Denmark | Public (Oslo: ASTK) | Liquid cooling systems for HPC and enterprise; rack CDU and direct-to-chip cold plates; significant OEM server partnerships. |
| Engineered Fluids | Minneapolis, MN, USA | Growth | BitCool and ElectroCool dielectric fluids for single-phase immersion; positioned as alternative to discontinued 3M Novec products. |
| Corintis | Lausanne, Switzerland | Series A | Microfluidic chip-scale cooling: AI-optimized microscopic channels etched into chip metal route coolant directly to thermal hotspots; 3x heat removal vs. standard cold plates (Microsoft-tested); EPFL POWERlab spinout. |
Public Companies
| Ticker | Company | Mission |
|---|---|---|
| VRT | Vertiv Holdings | Thermal management, power, and IT infrastructure for datacenters; Liebert precision cooling, CDUs, busway; significant AI datacenter exposure. |
| OSTK / ASTK | Asetek | HPC and enterprise liquid cooling; Oslo-listed; direct-to-chip and rack CDU products. |
Incumbents
| Ticker | Company | Relevance |
|---|---|---|
| ETN | Eaton | Power distribution and cooling infrastructure; significant datacenter UPS and PDU market; expanding into liquid cooling adjacencies. |
| SCHN | Schneider Electric | APC datacenter infrastructure; EcoStruxure DCIM; cooling, power, and management systems at scale; largest legacy datacenter infrastructure vendor. |
| NVT | nVent Electric | Thermal management and enclosures; Schroff racks; expanding into liquid cooling for high-density racks. |
| 3M | 3M | Novec engineered fluids (discontinued 2025 due to PFAS regulation); exit created supply gap in single-phase immersion cooling fluid market. |
Supply Chain
Supply Chain Layers
| Layer | Key Inputs / Outputs | Companies Operating Here | Geographic Risk |
|---|---|---|---|
| 1. Raw Materials | Fluorinated compounds (dielectric fluids), copper (cold plates, CDUs), aluminum (heat sinks), stainless steel (tanks) | 3M (Novec — exiting), Solvay (Galden), Shell, Engineered Fluids | Fluorinated fluid production: US and European chemical companies; 3M exit creating supply gap |
| 2. Dielectric Fluids | Engineered single-phase and two-phase dielectric fluids for immersion | Engineered Fluids (BitCool), Shell Immersion Cooling Fluid, Submer SmartCoolant, Solvay Galden (two-phase) | Post-3M-Novec exit: supply more distributed but still specialty chemicals with limited producers |
| 3. Heat Transfer Components | Cold plates (direct-to-chip), heat exchangers (CDU), manifolds | CoolIT, Aavid/Boyd (thermal management), Liqtech (ceramic membrane, adjacent) | Cold plate manufacturing: North American and Asian suppliers |
| 4. Complete Cooling Systems | Immersion tanks, rack CDUs, RDHx units, precision air handlers | Submer, LiquidStack, GRC, Iceotope, CoolIT, Asetek, Schneider Electric (APC InRow) | Assembly: distributed; tank manufacturing requires welding/fabrication capability |
| 5. Facility Integration | Chilled water loops, dry coolers, cooling towers, CDU interconnect | Vertiv, Schneider Electric, Johnson Controls (York chillers), CBRE (design/build) | Chillers and cooling towers: global manufacturing base |
Key Supply Chain Notes
3M Novec discontinuation: 3M announced discontinuation of its PFAS-based Novec engineered fluid product line in 2025 due to regulatory pressure around per- and polyfluoroalkyl substances (PFAS). Novec was the dominant fluid for single-phase immersion cooling. Operators with existing Novec-based immersion deployments face a fluid supply transition, and new deployments are shifting to alternatives: Engineered Fluids BitCool, Shell’s immersion fluid, and Submer’s SmartCoolant. This represents a significant supply chain disruption for the immersion cooling sector — track replacement fluid qualification status at major operators.
PUE reality check: Data center operators frequently quote design PUE rather than measured operational PUE. Liquid cooling achieves genuinely low PUE (1.02–1.10 in practice), but the benefit is only real if the facility-side cooling infrastructure (chillers, cooling towers, dry coolers) is also efficient. A liquid-cooled IT load connected to an inefficient chiller plant can have worse PUE than a well-designed air-cooled facility with economizer. Verify PUE claims by asking for annualized measured figures, not design targets.
⚑ Shared challenge — robot servicing incompatibility: Standard single-phase immersion tanks (Submer SmartPod, GRC CarnotJet) require servers to be lifted vertically out of fluid — a fundamentally different motion than horizontal rack-slide operations. This incompatibility with conventional robot-servicing approaches (which assume rack-slide) is the core design problem that Submer’s ADA robot and SoftBank’s cable-less rack design address from different angles. See Robotics & Automation and SoftBank Robot Rack.