Thermal Systems Engineer

Job description

WHAT TO EXPECT Heron Power is a startup company building cutting-edge power electronics for the 21st-century grid. We aim to de-bottleneck the growth of electricity generation and consumption with scalable, innovative, and less costly hardware solutions, accelerating the electrification of everything. Our first goal is to build better converters (inverters & rectifiers) to connect large-scale renewables, storage, and loads to the grid. Heron’s leadership team is made up of seasoned veterans who have designed and shipped gigawatts of power conversion products over the past decade. We understand that no one individual knows everything. We will all learn a lot together and from each other. We strive to build a collaborative, enriching environment conducive to personal, technical, and career growth. You can expect to work in a dynamic environment, driven by first principles engineering, solving difficult problems—with a strong bias toward hands-on execution and learning by doing. JOB OVERVIEW Uptime, availability, and reliability are critical to our converters (inverters & rectifiers) that connect large-scale renewables, storage, and high-power loads (e.g., data centers) to the grid. Our team focuses on delivering a deep, physics-based understanding of our systems from architecture to field, enabling designs that are reliable, safe, and high performing. We unite systems engineering, modeling, reliability, testing, and failure analysis into a single team that partners with design engineering. We collaborate on the deepest technical questions by challenging assumptions. As a Thermal Systems Engineer, you will architect, design, build and operate the test infrastructure that lets us validate thermal systems for grid-tied converters that will become part of the electrical infrastructure ahead. This role owns the development lifecycle loop from: design-reviews → failure modes → test strategy → bench design/build → test execution → data analysis → root cause → verified fixes. You’ll uncover design and process failures by executing physical tests and developing automated test equipment and data workflows. If you thrive on building capability from scratch, love lab work, and want your work to directly set the pace of iteration, this role will feel like home. HOW YOU WILL CONTRIBUTE Thermal & Fluids Testing (Component → System) - Execute thermal and fluids testing from component-level characterization (e.g., valves, pumps, fans, heat exchangers, insulation materials) through full thermal-system validation. - Develop test plans and Design-of-Experiments (DoE) in partnership with thermal analysis and mechanical design teams—turning hypotheses into crisp pass/fail criteria and learning goals. - Define instrumentation plans to ensure we’re measuring what matters (temperatures, pressures, flows, ΔP, thermal resistances, transients). Test Stand Architecture & Build - Design fixtures and rigs; procure and integrate test equipment including thermocouples/RTDs, pressure sensors, flowmeters, anemometers, DAQs. - Size and integrate plumbing for support equipment (chillers, pumps, fans, reservoirs, filters, fittings, hoses, quick disconnects) to enable safe, repeatable testing. - Own end-to-end bench build quality: layout, plumbing, grounding/EMI considerations near power electronics, safety interlocks, and maintainability. Automation, Data, and Reporting - Automate test execution, data logging, and post-processing to enable repeatable test campaigns and fast iteration loops. - Build data analysis workflows that produce actionable outputs (not just raw logs): clear plots, summaries, and “what changed / why it matters” reporting. Root Cause, Failure Analysis, and Feedback Loops - Drive root cause and failure analysis when tests go sideways: reproduce, instrument deeper, isolate failure mechanisms, and validate corrective actions. - Close the loop with design engineering—ensuring fixes are verified and regression-proof. WHAT YOU WILL BRING We prioritize a strong foundation in first principles, practical skills, an inquisitive mindset, and a proactive attitude. We care as much (or more) about how you work as what you already know. We will calibrate seniority based on demonstrated results, depth and ownership, not keywords. MUST-HAVE REQUIREMENTS - A degree in Mechanical Engineering or related fields, with background in thermodynamics or fluids engineering - >2 years of industry or research experience in a lab environment with proven hands-on experience in testing and developing test fixtures - Sound knowledge and fundamental understanding of flow physics, hydraulics, thermal / heat transfer - Experience with scripting in Python / Matlab and comfortable using source control like Github / Bitbucket - Experience using different types of DAQs and equipment from thermocouples, flow sensors, pressure sensors, anemometers etc. - Strong communication skills in terms of presentations and writing detailed technical reports - Sound mathematical and physics background to perform basics engineering calculations NICE-TO-HAVES - Simulation and modelling experience in fluid network analysis, thermal / RC and CFD modelling, commercial CAD packages - Reliability and statistical analysis - Experience with power electronics and high voltage testing - Prior experience in shipping products for UL certification If you are passionate about technology and enjoy working in a fast-paced environment, we would love to hear from you. Join us in accelerating the electrification of everything at Heron Power. Heron Power provides competitive compensation (salary and equity) and benefits. The salary for this role ranges from $120,000 to $190,000 per year.