Senior Performance Engineer, Thermal Modeling

XNRGY Climate Systems • Mesa, AZ

5d • Hybrid

About The Position

Reporting to the Manager, CPQ Tools & Selection Software, the Senior Performance Engineer, Thermal Modeling owns the physics behind our selection tools, developing and validating the performance models that determine how our equipment is selected, rated, and represented to customers. You’ll work across cutting-edge chiller and data center cooling technologies, from compressor and refrigerant-cycle modeling to chilled-water coils, psychrometrics, fan arrays, and acoustics. This is a hands-on role working directly with test data, build and improve engineering models, and see your work move from the test stand into commercial selection tools, partnering closely with stakeholders to ensure what the tool predicts matches what the equipment actually delivers. The role is based in Mesa, AZ with hybrid flexibility and occasional travel to test facilities, supplier test sites, and customer or consultant meetings.

Requirements

• Bachelor’s degree in Mechanical Engineering, Thermal Engineering, or a related engineering discipline.
• 7+ years of experience in HVAC, refrigeration, turbomachinery, or related performance engineering.
• Experience developing and validating empirical or semi-empirical performance models against test data, with strong knowledge of thermodynamics, heat transfer, and psychrometrics.
• Deep expertise in either air-side or refrigerant-side performance modeling, with working knowledge of the other; Air-side experience with data center cooling is strongly preferred.
• Experience with performance testing, test data analysis, measurement uncertainty, and model-to-test correlation, with proven judgment around data quality.
• Proficiency with technical computing tools such as Python, MATLAB, or equivalent, and experience working with engineering data and property libraries such as CoolProp or REFPROP.
• Ability to travel approximately 20% of the time, including trips to test facilities, supplier test sites, and customer or consultant meetings.

Nice To Haves

• Familiarity with SQL and Git is a plus.

Responsibilities

• Develop and maintain thermal and performance models for chiller and air-side systems, incorporating real-world equipment behavior and operating conditions.
• Compare model predictions against test data, identify discrepancies and root causes, and improve model accuracy and robustness.
• Work closely with Testing & Labs to define test requirements, analyze results, validate models, and establish certified operating envelopes.
• Translate engineering models and test results into reliable selection logic, including off-design conditions, part-load operation, and coupled product performance.
• Support AHRI, ASHRAE, and AMCA ratings, certifications, performance documentation, and standardized model outputs.
• Serve as the technical performance expert for stakeholders, helping resolve complex selections and performance questions and supporting customer-facing requirements.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior