Careers
Build the heat pump designed to keep heating when others stop.
AReCoS, founded in Grand Rapids, Michigan in 2023, is hiring a few founding engineering leads to own its first commercial heat pumps, from the physics model to the production line, with early equity in what they build.
Why AReCoS
Hard engineering, early, with real ownership.
A problem worth solving
Frost has long forced air-source heat pumps to stop heating and defrost. The AReCoS air–water heat exchanger is designed to keep frost to a thin layer it clears while heating, so buildings can leave gas behind.
Protected technology
The embedded controller is patented, U.S. Patent 12,768,557, and the heat exchanger is patent pending. We also work with Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC, under a research agreement, a CRADA.
Founding roles
Set the architecture, tools and standards the company grows on, and hire the teams that follow.
Equity that becomes ownership
Equity vests on delivery, not on a four-year clock: for the early team it becomes ownership once we deliver the hardware defined in the company's contract at commercial readiness level. Every founding lead receives it alongside a competitive salary.
How we work
What we expect of each other.
Own the outcome
Each lead owns a part of the product end to end, and says early when something is off.
Physics first
Decisions rest on models, measurements and first principles, not on opinion or habit.
Claims we can defend
We tell customers, partners and investors only what the evidence supports.
Built for the customer
Owners, contractors and service technicians decide whether we succeed; we design for their day.
Open roles
We are hiring founding leads across eight roles.
Hiring is staged: thermal modeling, mechanical design and manufacturing first, the rest to follow. Tell us your role and we will tell you where it sits in the order.
We want engineers whose work stands out: products shipped, solvers and models others rely on, publications others build on. Every role is full time and reports to both the chief technology officer and the founder and CEO, who also leads product.
Show requirements and offer terms
Requirements differ by role. The thermal modeling and CFD leads require a PhD. The mechanical design and manufacturing leads can bring a PhD or the equivalent in years of taking products through development and launch. The HVAC systems and standards lead brings commercial HVAC practice, a PE license preferred. The model-based design, embedded software and embedded hardware leads bring years of shipping production embedded controllers.
Salary ranges are base pay; the final offer depends on experience. Equity vests on delivery, as set out above, under the terms of the AReCoS equity plan. Ownership ranges and vesting terms are set out in each offer, and applications are treated confidentially.
Lead Thermal Modeling Engineer
$140,000 – $175,000+ early equity
Role details and how to apply
Lead Thermal Modeling Engineer
$140,000 – $175,000+ early equity
Own the physics of the AReCoS heat pump: first-principles models of the refrigerant cycle, the air–water heat exchanger and the water and ground loops. The product, its controller and its certification are built on those models.
What you will do
- Lead dynamic and steady-state modeling of vapor-compression cycles: moving-boundary and finite-volume heat exchangers, compressors, valves and two-phase flow.
- Model frost, heat and mass transfer, and the air–water heat exchanger. Turn those models into design decisions on capacity, efficiency and cold-weather performance.
- Build the model-based verification that proves each controller against the full physics model across the operating envelope.
- Plan and correlate laboratory and field tests with manufacturers and ORNL; predict AHRI ratings and cold-climate performance before hardware exists.
- Set modeling standards, reviews and documentation, and hire the thermal team.
What you bring
- PhD in mechanical, chemical or aerospace engineering, or a related field, with a dissertation in thermal-fluid systems, heat transfer or refrigeration.
- 10+ years of research or industry experience modeling vapor-compression, heat pump or HVAC&R systems.
- Expert command of MATLAB/Simulink, Modelica or Python, and refrigerant property tools such as CoolProp or REFPROP.
- A record of peer-reviewed publications or models that shipped in a product.
- Nice to have: frost and defrost physics, ground-source systems, model-based control design.
Send your CV, a list of publications and a short note on the hardest model you have built.
Lead Mechanical Design Engineer
$135,000 – $170,000+ early equity
Role details and how to apply
Lead Mechanical Design Engineer
$135,000 – $170,000+ early equity
Own the design of the all-season heat pump rooftop unit, from the air–water heat exchanger and refrigerant circuit to the cabinet, and carry it through prototypes, safety listing and the first production builds.
What you will do
- Lead the mechanical architecture of the 10-ton rooftop unit and the 5-ton residential heat pump: heat exchangers, piping, cabinet, airflow and serviceability.
- Design the patent-pending air–water heat exchanger for performance, manufacturability and cost, using CFD and structural analysis where they matter.
- Own CAD, drawings, GD&T, tolerance stacks and the bill of materials, and run design reviews and DFMEA.
- Design for UL 60335-2-40, A2L refrigerant safety (R-454B), AHRI rating tests and ASHRAE 15 from the first sketch.
- Build and test prototypes with suppliers and manufacturing partners, and hire the mechanical team.
What you bring
- PhD in mechanical or aerospace engineering or a related field, or a B.S./M.S. with 15+ years of equivalent product-development experience, with depth in thermal systems, heat exchangers or mechanical design.
- A track record designing HVAC&R, heat pump, automotive thermal or comparable electromechanical products taken to production.
- Expert command of SolidWorks, Creo or NX, with CFD or FEA experience.
- Working knowledge of refrigerant circuit design, brazed joints, pressure-vessel and safety standards.
- Nice to have: A2L refrigerant products, microchannel or plate heat exchangers, sheet-metal cabinets.
Send your CV and two or three products or prototypes you designed, with your part in each.
Lead Manufacturing Engineer
$130,000 – $165,000+ early equity
Role details and how to apply
Lead Manufacturing Engineer
$130,000 – $165,000+ early equity
Take the AReCoS heat pump from prototype to production with selected manufacturing partners: processes, quality, suppliers and cost. Pilot units are targeted for 2027 and the first commercial units for 2028.
What you will do
- Select and qualify contract manufacturers and key suppliers for compressors, heat exchangers, controls and cabinets.
- Develop the production processes for the air–water heat exchanger and the refrigerant circuit: brazing, leak testing, evacuation, charging and end-of-line run testing.
- Lead PFMEA, control plans, PPAP-style part approval and first-article inspection with partners.
- Own manufacturing cost, capacity and ramp plans for the first units and the scale-up after them.
- Prepare production for safety listing and rating-program audits, and hire the manufacturing and quality team.
What you bring
- A B.S./M.S. with 20+ years launching HVAC&R or comparable products, or a PhD in manufacturing, mechanical, industrial or materials engineering.
- Manufacturing engineering experience for HVAC&R, appliance, automotive or comparable products, including a new product launch.
- Hands-on knowledge of brazing, heat-exchanger production, refrigerant handling and leak testing.
- Lean and Six Sigma methods; a Black Belt is a plus.
- Nice to have: contract-manufacturing launches, A2L refrigerant production lines, UL and AHRI audits.
Send your CV and a short note on a product launch you led, and what you would do differently.
Lead CFD Engineer
$140,000 – $175,000+ early equity
Role details and how to apply
Lead CFD Engineer
$140,000 – $175,000+ early equity
Own the flow and heat-transfer analysis behind the AReCoS heat pump: airflow through the rooftop unit and its coils, the air–water heat exchanger, and the fans and cabinet. Take it from high-fidelity studies to fast, validated tools the design team uses daily.
What you will do
- Lead CFD of heat exchangers, fans, cabinets and airflow paths, including conjugate heat transfer, turbulence and two-phase or multiphase flow where it matters.
- Build and automate CFD workflows in OpenFOAM and commercial tools such as ANSYS Fluent: geometry clean-up, meshing, solver set-up, post-processing and parametric sweeps.
- Write and extend solvers, boundary conditions and utilities in C++ and Python, and run them in parallel with MPI on workstations and cloud clusters.
- Turn CFD results into reduced-order correlations for the thermal models and the controller, and validate them against laboratory and manufacturer test data.
- Set CFD standards, verification and mesh-convergence practice, and hire the CFD team.
What you bring
- PhD in aerospace, mechanical or chemical engineering, or a related field, with a dissertation in CFD, turbulence (RANS, LES or DNS) or numerical methods.
- 10+ years of research and industry experience in CFD, including solver development or advanced use of OpenFOAM, ANSYS Fluent or comparable codes.
- Strong programming in C/C++ and Python, with MPI or OpenMP, git and Linux.
- Meshing and post-processing tools such as Pointwise, ICEM, Gmsh, ParaView or Tecplot, and CAD such as SolidWorks.
- A record of peer-reviewed publications; nice to have: heat exchanger or HVAC&R flows, fan and aeroacoustic noise, GPU or high-order methods.
Send your CV, a list of publications and a short note on a solver or model you built and how you validated it.
Lead HVAC Systems and Standards Engineer
$130,000 – $165,000+ early equity
Role details and how to apply
Lead HVAC Systems and Standards Engineer
$130,000 – $165,000+ early equity
Own the AReCoS heat pump rooftop unit’s path through the ratings, codes and building interfaces that owners, contractors and utilities rely on: from AHRI rating and safety listing to BACnet integration, demand response and field measurement.
What you will do
- Lead the rating and certification plan: AHRI 340/360 and 210/240 test plans, the transition to AHRI 1340 (IVEC and IVHE), and UL 60335-2-40 listing with the test laboratories.
- Own refrigerant safety for R-454B: A2L leak detection and mitigation to UL 60335-2-40 and ASHRAE 15 and 15.2, with ASHRAE 34 classification, and installation guidance.
- Define the building interface: the BACnet (ASHRAE 135) points list, ASHRAE Guideline 36 sequences for rooftop units, and demand response through OpenADR via the building automation system.
- Write the application guides contractors use: curb, electrical, ventilation to ASHRAE 62.1, energy-code compliance with ASHRAE 90.1 and the IECC, and commissioning to ASHRAE Guideline 0 and Standard 202.
- Plan measurement and verification at pilot sites with utilities, following IPMVP and ASHRAE Guideline 14, and turn field data into the unit specification.
What you bring
- B.S. or M.S. in mechanical or architectural engineering; a Professional Engineer license preferred.
- 10+ years in commercial HVAC with rooftop units, heat pumps or controls, at an equipment manufacturer, controls integrator or engineering firm.
- Working command of ASHRAE 90.1, 62.1, 15, 34 and 135, AHRI 340/360 and 210/240, and UL 60335-2-40 with A2L refrigerants.
- Hands-on BACnet integration and building-automation commissioning, and experience with demand response or utility efficiency programs.
- Nice to have: ASHRAE certifications (BEAP, BCxP or HBDP), AHRI or UL certification projects, cold-climate heat pump field studies.
Send your CV and a short note on a rating, listing or BACnet integration you led.
Lead Model-Based Design Software Engineer
$130,000 – $165,000+ early equity
Role details and how to apply
Lead Model-Based Design Software Engineer
$130,000 – $165,000+ early equity
Own the model-based design flow that turns the company's physics models and control laws into verified production code on the AReCoS embedded controller.
What you will do
- Build and maintain the controller models in Simulink and Stateflow: state estimation, actuator coordination, and startup, shutdown and changeover logic.
- Generate production C code with Embedded Coder, and keep requirements, models and code traceable.
- Run model-, software- and processor-in-the-loop testing, and hardware-in-the-loop tests against the full physics model of the unit.
- Set modeling guidelines, model reviews, version control and continuous integration for models.
- Take each control feature from the model to the unit with the thermal modeling and embedded software leads, and hire the model-based design team.
What you bring
- B.S. or M.S. in electrical, mechanical, aerospace or controls engineering; a PhD is a plus.
- 8+ years of model-based design for production embedded controllers in automotive, aerospace, HVAC&R or industrial products.
- Expert command of Simulink, Stateflow and Embedded Coder, with MIL, SIL, PIL and HIL practice (Simulink Test, dSPACE, Speedgoat or NI).
- Control engineering depth: state-space design, observers and Kalman filters, constrained optimization or model predictive control.
- Nice to have: ISO 26262, IEC 61508 or DO-178C processes, vapor-compression or thermal system control, AUTOSAR.
Send your CV and a short note on a controller you took from a Simulink model to production code.
Lead Embedded Software Engineer
$130,000 – $165,000+ early equity
Role details and how to apply
Lead Embedded Software Engineer
$130,000 – $165,000+ early equity
Own the software that runs on the AReCoS embedded controller: real-time firmware, drivers, communications and on-unit diagnostics, from first board bring-up to units in the field.
What you will do
- Architect the real-time firmware: RTOS, scheduling, and drivers for the unit's sensors and actuators, including the compressor drive, expansion-valve stepper, fans and pumps.
- Integrate generated control code from the model-based design flow with hand-written C and C++, and keep timing deterministic.
- Implement BACnet MS/TP and BACnet/IP, Modbus and secure firmware updates. Build the local network over which units are designed to share the load and agree on setpoints without a supervisory system.
- Build fault detection, on-unit fault codes, data logging and the service interface technicians use.
- Set coding standards (MISRA C), static analysis, unit and hardware-in-the-loop testing and continuous integration, and hire the embedded software team.
What you bring
- B.S. or M.S. in computer, electrical or software engineering.
- 8+ years developing production embedded C and C++ firmware on ARM Cortex-M or Cortex-A class processors, with an RTOS such as FreeRTOS, Zephyr or ThreadX.
- Field-bus and network protocols: BACnet, Modbus, CAN, Ethernet and TCP/IP.
- Debugging with JTAG, oscilloscopes and logic analyzers; git, continuous integration and static analysis tools.
- Nice to have: embedded Linux, IEC 60730 Class B software for appliance controls, IEC 62443 cybersecurity, over-the-air updates.
Send your CV and a short note on firmware you shipped and the hardest bug you found in it.
Lead Embedded Hardware Engineer
$125,000 – $160,000+ early equity
Role details and how to apply
Lead Embedded Hardware Engineer
$125,000 – $160,000+ early equity
Own the electronics of the AReCoS embedded controller: the boards that read the unit's sensors, drive its actuators and run its software, designed to last for years on a rooftop.
What you will do
- Architect and design the controller hardware: processor and power supplies; sensor inputs for pressure, temperature and humidity; actuator outputs for expansion-valve steppers, fans, pumps and relays; and RS-485, Ethernet and CAN interfaces.
- Capture schematics and lay out multilayer boards; own component selection, bill-of-materials cost and part lifecycle.
- Design for rooftop conditions: wide temperature range, moisture, surge and EMC (FCC Part 15, IEC 61000-4), with fail-safe outputs so the expansion valve closes and the compressor stops when power is lost.
- Bring up boards, run design verification and environmental testing, and prepare the controls for UL 60730 and UL 60335-2-40 evaluation.
- Work with contract manufacturers on design for manufacturing and test, and on production test fixtures, and hire the hardware team.
What you bring
- B.S. or M.S. in electrical engineering.
- 8+ years designing production embedded electronics for industrial, automotive, HVAC&R or appliance products.
- Expert command of Altium, KiCad or Cadence, with mixed-signal, power electronics and motor or valve driver design.
- EMC and safety design and testing, and hands-on lab work with oscilloscopes, spectrum analyzers and thermal chambers.
- Nice to have: variable-speed compressor or fan drives, harsh-environment and conformal-coated designs, IEC 60730 Class B hardware.
Send your CV and a short note on a board you designed that is now in production.
AReCoS is an equal opportunity employer. We welcome applicants of every background and consider all qualified applicants without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, veteran status or any other protected characteristic.
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Grand Rapids, Michigan 49546