CoolRacks: Passive Rack Cooling for AI & HPC

Technology Overview

Our systems use evaporation and condensation to transfer heat directly from the chip — no fans, no pumps, no noise.

Passive Cooling: Up to 2 kW per CPU/GPU in compact 1U servers.
Hybrid Systems: Combining gravity-driven and pump-assisted loops for 4 kW+ heat loads.

All designs are validated with proprietary solvers for precise, data-driven optimization.

Schematic of CoolRacks passive two-phase cooling system for servers and electronics

Proof of Concept

Seeing is believing. Explore operating prototypes, lab tests, and field demonstrations.

Highlights:
• Converted 1U–3U racks operating under realistic workloads
• Visualizations of two‑phase operation (evaporation/condensation)
• Bench tests, X‑ray inspections, and leak checks
• Short clips of assembly and hot‑swap procedures

Close-up of CoolRacks two-phase cooling hardware on server components

Performance & Validation

Validated results:
- Data center demo: 72h continuous operation under randomized workloads
- Partial PUE (pPUE) ~ 1.001 compared to ~1.40 for air-cooled baselines

Key metrics:
• Up to 35% TCO reduction (modelled vs. baseline)
• No expensive two-phase quick-disconnects or manifolds and hot-swapping enabled.
• 20%+ energy savings at datacenter level
• Stable passive operation at ~900–2000 W per device (prototyperange)
• Pumped two-phase coldplate/system to >4000W in development

Notes: Measurements based on controlled test campaigns; full OEM certification underway.

Performance and validation results comparing CoolRacks passive two-phase cooling to air-cooled baselines

Passive loop thermosyphon cooling system (LTS) designed for CPUs of 1U servers

Passive pulsating heat pipe cooling system (PHP) designed for CPUs of 1U servers

Applications

Enabling high-density computing across:
- High-Performance Computing (HPC)
- AI & GPU clusters
- Colocation & Hyperscale data centers
- Edge & Telecom infrastructure
- Defense & Aerospace electronics

Benefits: Compact, scalable, low cost, maintenance-free, and waterless.

Partners & Case Studies

We collaborate across the value chain — from component suppliers and system integrators to server OEMs and data center operators.
Engagement types:
• Reference designs with OEMs
• Retrofit pilots for colocation
• Evaluation programs for hyperscale deployment
• Joint validation and certification plans

Sustainability & Impact

Waterless cooling with eco-friendly refrigerants reduces environmental impact while enabling denser compute.
Benefits:
• 20%+ energy savings vs. air-cooled baselines
• Lower CO₂ emissions via reduced facility power
• Quiet operation; minimal moving parts
• Potential for waste-heat recovery at rack level

CoolRacks: Passive Two-Phase Cooling for High-Density Racks

We design low-cost, scalable, and maintenance-free cooling systems that push the limits of thermal performance in servers and electronics.