Principal CDU Engineer

OptiCool
Webster, NY

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.

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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:

o Two-phase cooling systems (boiling/evaporative heat transfer)

o Refrigerant-based direct expansion (DX) or pumped refrigerant loops

o Transcritical and subcritical CO₂ cooling systems

o 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

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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)

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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

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Key Competencies

· 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

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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

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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

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