Role OverviewWe're looking for a Sr. Heat Exchanger Engineer to own the design, specification, and development of heat exchangers across Arbor's supercritical CO₂ power system. You'll span the full range-from specifying and technically managing third-party shell-and-tube coolers and air coolers, to leading in-house detailed design of advanced compact heat exchangers in high-temperature nickel superalloys. You'll work closely with thermodynamic cycle analysts, mechanical systems engineers, and test engineers in a fast-paced, hands-on R&D environment. This is a rare opportunity to apply deep thermal-fluids and manufacturing expertise to climate-impactful technology at the frontier of power generation.
This is an onsite opportunity in our El Segundo, CA office.
Responsibilities- Own the thermal-hydraulic design of all heat exchangers in the Arbor power system-recuperators, precoolers, primary heat exchangers, and water and air coolers-from conceptual sizing through detailed design, balancing performance, pressure drop, and cost.
- Lead in-house design and development of advanced compact heat exchangers, including printed circuit heat exchangers (PCHEs) and components produced by additive manufacturing (AM) in materials such as 316SS, Inconel 625, and Haynes 282; apply design for additive manufacturing (DfAM) principles to translate geometric freedom into manufacturable, high-performing hardware.
- Specify, procure, and technically manage third-party heat exchangers-including shell-and-tube coolers, fin-fan air coolers, and advanced compact units-from thermal datasheet through vendor drawing review and factory acceptance testing.
- Collaborate with a dedicated pressure vessel engineer on mechanical design under ASME, TEMA, and API 661; maintain working familiarity with applicable codes to make sound design decisions and effectively review deliverables.
- Plan and execute thermal and hydraulic performance testing during development campaigns: define instrumentation requirements, write test procedures, lead data reduction, and anchor analytical models to test data.
- Collaborate closely with thermodynamic cycle analysts, mechanical systems engineers, and test engineers to translate cycle-level requirements into hardware specifications and integrate heat exchangers into the broader power system.
- Champion design for manufacturability and scalability across in-house heat exchanger development programs, bridging detailed design and production to bring novel hardware from concept to reality.
- Generate and maintain the full engineering documentation package: thermal and mechanical calculation packages, drawings, material and process specifications, and test reports.
Requirements- Bachelor's degree in Mechanical, Chemical, Aerospace, or related Engineering field.
- 10+ years of experience in heat exchanger design and development, spanning thermal-hydraulic analysis, mechanical design, and hardware validation.
- Demonstrated experience designing advanced compact heat exchangers-PCHEs, plate-fin, microchannel, or similar-including selection and optimization of channel geometry for performance, pressure drop, and manufacturability.
- Experience specifying and technically managing conventional heat exchangers (shell-and-tube, air-cooled) per TEMA and API 661 standards.
- Working familiarity with ASME Boiler and Pressure Vessel Code and its application to heat exchanger mechanical design.
- Proficiency in industry thermal design tools (HTRI or equivalent) and scripting or computation for custom analyses (Python, MATLAB, or similar).
- Proven track record of taking heat exchanger hardware from design through fabrication and performance validation in a hands-on engineering environment.
- Strong ownership mentality with the ability to drive technical programs independently in a small, fast-paced startup environment.
Preferred Qualifications- Experience with supercritical CO₂ or other supercritical or dense-phase working fluids.
- Background in metal additive manufacturing (laser powder bed fusion, binder jetting, or directed energy deposition) applied to heat exchanger or thermal device design and qualification.
- Experience bridging detailed design and production-developing or scaling manufacturing processes for novel hardware, not just specifying for outside vendors.
- Background in startup, R&D, or first-of-a-kind hardware development environments.
Compensation & Benefits- Pre-IPO stock options
- Medical, dental, and vision insurance (Arbor covers 90% for employees)
- Basic life insurance fully covered
- Health savings account (HSA) with matching
- Flexible savings account (FSA)
- Unlimited PTO
- 12+ company holidays, including Earth Day!
- 401(k)
- Commuter benefits
- Annual learning and development stipend
- And more!
Base Pay: $165,000 - $180,000 USD/year. The salary is subject to the applicant's skills, qualifications, experience, and geographic location.
