Principal Thermal Engineer

We are seeking a highly experienced Principal Engineer to lead the design, development, and optimization of Coolant Distribution Units (CDUs) for hyperscale data center environments. This role is central to enabling next-generation liquid cooling solutions for AI and high-density compute, with a strong emphasis on maximizing heat extraction capacity per unit footprint and volume.

A key focus of this role is to innovate and develop new heat extraction approaches, including the application of refrigerant-based and CO₂-based cooling technologies, to push beyond the limits of traditional water-based CDU systems.

Key Responsibilities

• Lead end-to-end design of CDU systems supporting hyperscale deployments, including primary/secondary loop architecture
• Define system requirements aligned with hyperscaler priorities: maximum kW removed per CDU footprint, rack density scaling, and floor space efficiency
• Design and integrate high-performance components: pumps, compact heat exchangers, manifolds, filtration systems, and controls
• Optimize CDU designs for maximum heat transfer per square foot (kW/ft²) and per unit volume (kW/m³)
• Drive innovation in advanced heat extraction technologies, including:
  • Two-phase cooling systems (boiling/evaporative heat transfer)
  • Transcritical and subcritical CO₂ cooling systems
  • Hybrid liquid–refrigerant architectures for ultra-high heat flux applications
• Evaluate and implement phase-change cooling strategies to significantly increase heat transfer coefficients and reduce system footprint
• Lead feasibility studies comparing water vs. dielectric fluids vs. refrigerants vs. CO₂ for performance, safety, cost, and scalability
• Address system challenges including pressure management, leak mitigation, safety compliance, and material compatibility for refrigerant/CO₂ systems
• Conduct advanced thermal and fluid modeling (including two-phase flow and phase-change dynamics)
• Optimize system-level tradeoffs between heat extraction capability, energy efficiency, and mechanical complexity
• Develop CDU concepts capable of supporting 100–300+ kW per rack and future scaling beyond
• Ensure compliance with evolving environmental and regulatory considerations (low-GWP refrigerants, sustainability goals)
• Collaborate with hyperscale customers and partners to align next‑generation CDU architectures with future infrastructure roadmaps
• Lead prototyping and validation of novel cooling architectures, including lab-scale and full-scale demonstrations

Required Qualifications

• Bachelor’s or Master’s degree in Mechanical, Thermal, or Chemical Engineering (or related field)
• 10+ years of experience in thermal-fluid systems, including liquid and/or refrigerant-based cooling
• Demonstrated experience with two-phase heat transfer, refrigeration cycles, or advanced cooling technologies
• Strong understanding of heat transfer, fluid dynamics, and thermodynamics in both single-phase and two-phase systems
• Experience designing for high heat flux and space‑constrained environments
• Proven ability to innovate and bring new thermal management concepts from idea to prototype
• Proficiency with CAD and advanced simulation tools (CFD, two-phase modeling where applicable)

Preferred Qualifications

• Experience with refrigerants (e.g., HFOs, HFCs) and CO₂ (R-744) cooling systems in industrial or data center applications
• Familiarity with ASHRAE standards (including refrigerant safety classifications) and Open Compute Project liquid cooling initiatives
• Knowledge of direct‑to‑chip, immersion cooling, and hybrid cooling architectures
• Experience addressing regulatory, safety, and environmental constraints (pressure systems, refrigerant handling, low‑GWP requirements)
• Background in system controls for managing dynamic thermal loads and phase‑change systems
• Experience working with hyperscalers or next‑gen data center infrastructure providers

• Innovation in next‑generation thermal management technologies
• Systems‑level thinking across mechanical, thermal, and refrigeration domains
• Strong analytical capability in multi‑phase heat transfer and system optimization
• Ability to evaluate emerging technologies and translate them into scalable products
• Leadership in cross‑functional, R&D‑driven engineering teams

Success Metrics

• Heat extraction density (kW per CDU footprint and volume)
• Demonstrated advancement of next‑generation cooling concepts (refrigerant/CO₂ adoption, prototypes, patents)
• Maximum supported rack density (kW/rack), including next‑gen AI workloads
• Thermal efficiency and system COP improvements
• Reduction in total cost of ownership (TCO) at hyperscale
• Reliability and safety performance of advanced cooling systems

Why Join Us

• Lead innovation at the frontier of data center cooling evolution beyond water‑based systems
• Work on breakthrough technologies enabling future AI infrastructure
• Influence industry direction toward higher efficiency and sustainable cooling solutions
• Collaborate with leading hyperscalers and technology innovators