Principal Thermal R&D Engineer

Johnson Controls, a global leader in thermal management, mission‑critical building systems, energy efficiency, and decarbonization, helps customers use energy more productively, reduce carbon emissions, and operate with the precision and resilience required in rapidly expanding industries such as data centers, healthcare, pharmaceuticals, advanced manufacturing, and higher education. For more than 140years, Johnson Controls has delivered performance where it really matters. Backed by advanced technology, lifecycle services and an industry‑leading field organization, we elevate customer performance, turn goals into real‑world results and help move society forward.

Visit  for more information and follow @Johnson controls on social platforms.

Johnson Controls is hiring! As Principal Thermal R&D Engineer, you'll be a senior technical contributor driving research and development of next‑generation thermal management devices built on Johnson Control’s patented Stack Forging process. You'll own the technical direction of our research programs including identifying promising cooling technologies and device architectures, building and testing prototypes, and maturing them to the point where they can be handed off for commercialization.

The devices you develop will go directly into the systems where thermal limits are being pushed hardest. You'll work closely with the Customer Solutions team and the wider Johnson Controls organization to understand where our customers' thermal challenges are heading and how our technology roadmap should respond. You'll translate those needs into a research portfolio, define and execute the projects within it, and serve as the technical authority on thermal‑fluid performance across the company.

You're a deep thermal‑fluids expert who is equally comfortable at a test bench and inside a CFD model. You've taken cooling concepts from whiteboard to working hardware, and you understand single‑and‑two‑phase heat transfer, pressure drop, and flow distribution well enough to know which internal geometries will matter before you simulate them. You know how to design an experiment that gives a clean answer, and you distrust a simulation that hasn't been validated against one.

You're self‑directed and hands‑on. You're comfortable with the ambiguity of research and disciplined enough to know when a technology is ready to leave the lab.

Partner with the Solutions team and Johnson Controls stakeholders to identify emerging customer thermal requirements and cooling technologies, and shape the thermal technology roadmap to meet them. Scope and propose research projects with clear hypotheses, success criteria, timelines, and resource needs; secure alignment with leadership and report on progress. Conceive novel thermal device architectures that exploit the internal microgeometry freedom of Stack Forging to deliver performance conventional manufacturing can't.

Work with our simulation team to complete CFD and thermal‑fluid analysis to screen concepts, predict performance, and guide design iteration ahead of hardware builds. Advance the company's capability in two‑phase and refrigerant‑based cooling, including boiling and condensation behavior, flow stability, and working fluid selection. Design and build test rigs, define test protocols, execute experiments, and analyze data to validate device performance and quantify uncertainty.

Act as the technical authority on thermal performance; review designs, mentor engineers, and set the standard for analytical and experimental rigor.

• Required PhD in Mechanical Engineering, Thermal‑Fluid Sciences, or a related field with 8+ years of experience, or an MS/BS…