Senior Modeling Engineer

What You Will Do Johnson Controls’ Data Center Thermal Technology Solutions group is seeking a Senior Modeling Engineer. As a member of the modeling team, you will develop and apply numerical models to simulate the end-to-end performance of data center cooling systems. You will play a key role on cross-functional teams responsible for creating comprehensive thermal solutions for data center applications. Your primary focus will be simulating system performance and providing design and application guidance based on model results. As part of the advanced development team, you will also stay current on emerging technologies in the data center cooling space and evaluate innovations that may influence future product offerings. We prefer to have this candidate based in our Glendale, WI, or York, PA, office; however, this can also be a remote opportunity for the right candidate! How You Will Do It Develop numerical simulations of thermal components commonly used in data center applications. Integrate subsystems into complete thermal solutions, coordinating across cooling loops, controls, and heat-rejection equipment. Use simulation tools to predict chip-to-ambient performance of data center cooling systems. Apply system-level performance models to provide technical guidance to customers. Present project status, technical findings, and strategic recommendations across departments. Deliver presentations and/or write white papers communicating JCI’s technical perspective on emerging technologies and system architectures. Actively participate in industry groups such as ASHRAE and the Open Compute Project. What You Will Need Required Master’s or PhD in Mechanical Engineering or a related field. 3+ years of industry experience with thermal products or systems. Strong theoretical foundation in thermodynamics, heat transfer, and fluid mechanics. Experience with HVAC system design, refrigerant cycles, and component selection. Proficiency with numerical simulation tools for building and thermal applications (e.g., Modelica, MATLAB/Simulink, EES, EnergyPlus). Broad cross-domain knowledge spanning thermal, controls, and electrical systems—generalists with strong multidomain capability are highly valued. Proficiency with Microsoft 365/Excel, including basic macros/VBA for data analysis and reporting. Demonstrated ability to execute cross-functional projects. Preferred Python scripting and environment management (package installation, virtual environments, basic automation). Fundamentals of controls engineering (feedback loops, PID tuning, system response). Basic understanding of electrical systems (motor sizing, VFDs, power distribution). Experience with refrigeration system design and refrigerant properties. Familiarity with data center cooling architectures (direct liquid cooling, rear-door heat exchangers, CDUs). Expertise in one or more thermal domains (CDUs, chillers, dry coolers, cold‑plate systems). Johnson Controls International plc. is an equal employment opportunity and affirmative action employer and all qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, age, protected veteran status, genetic information, sexual orientation, gender identity, status as a qualified individual with a disability or any other characteristic protected by law. To view more information about your equal opportunity and non-discrimination rights as a candidate, visit EEO is the Law. If you are an individual with a disability and you require an accommodation during the application process, please visit here. Johnson Controls: Enhancing the Intelligence of Buildings Your buildings have a purpose. They are places for people to live or work. Facilities for learning or healing. Venues for entertainment and shopping. Sites for the specialized storage of tangible goods or mission-critical data. Your buildings have a huge variety of functions; they are central to your mission. This is where Johnson Controls comes in, helping drive the outcomes that matter most. Through a full range of systems and digital solutions, we make your buildings smarter. A smarter building is safer, more comfortable, more efficient, and, ultimately, more sustainable. Most important, smarter buildings let you focus more intensely on your unique mission. Better for your people. Better for your bottom line. Better for the planet. At Johnson Controls, we’ve been making buildings smarter since 1885, and our capabilities, depth of innovation experience, and global reach have been growing ever since. Today, we offer the world’s largest portfolio of building products, technologies, software, and services; we put that portfolio to work to transform the environments where people live, work, learn and play.