Thermal Systems & Mechanical Engineer
Confirmed on the employer's own hiring board on Nov 2, 2026. First seen by Alion on Sep 2, 2026.
Your role.
We are looking for an experienced Thermal Systems & Mechanical Engineer to take technical ownership of the thermal management of our electric light commercial vehicles and the mechanical design that goes with it.
In this role, you own the thermal architecture of the vehicle: battery cooling and heating, power electronics and e-motor cooling, cabin climate, and the coolant and refrigerant circuits that connect them. You size these systems, design and integrate the mechanical hardware (pumps, valves, heat exchangers, lines and mounts) and make sure they work together across the full operating range, from alpine winters to fully loaded summer duty cycles.
You work closely with our mechanical, electrical and software teams. You define the thermal requirements and operating strategy together with software, and support development from concept through simulation and calculation to verification in the vehicle and in the field.
At Flux, you will work in a small team with short decision-making paths. You take ownership of technical decisions early and directly shape the architecture of our vehicles.
What you can contribute.
Take technical ownership of the vehicle's thermal architecture: battery thermal management, power electronics and e-motor cooling, cabin HVAC, and the associated coolant and refrigerant circuits.
Size and design cooling and heating systems, including pumps, valves, radiators, chillers, heat exchangers, expansion tanks, lines and heat pump and refrigerant circuits.
Carry out thermal sizing and simulation (1D system simulation and, where needed, CFD) and correlate models against component and vehicle test data.
Design and integrate the mechanical hardware of the thermal system into the vehicle (packaging, mounting, routing and interfaces to the vehicle structure) together with the design team.
Define the thermal requirements and thermal operating strategy together with the software team.
Plan and lead thermal verification and validation: component tests, climatic-chamber testing and on-vehicle testing in hot and cold conditions, in collaboration with external partners.
Work with suppliers of thermal components (compressors, pumps, heat exchangers, HVAC units) on selection, specification and validation.
Support aftersales and the field team with thermal-related field issues and root-cause analysis.
Analyse test and field data to continuously improve the thermal and mechanical design.
How you will succeed in this role.
Degree in mechanical engineering, automotive engineering, mechatronics, process/energy engineering or a comparable discipline.
At least 5 years of industry experience in thermal systems or thermal management, ideally in automotive or a comparably demanding industry.
Practical experience with vehicle thermal management topics such as battery cooling, HVAC/climate, refrigerant circuits or heat pump systems.
Experience with thermal and 1D system simulation tools (e.g. GT-SUITE, KULI, Simcenter Amesim or Simscape) and with correlating models to test data.
Solid mechanical design skills and a good understanding of fluid systems e.g. pumps, valves, heat exchangers and coolant/refrigerant circuits.
Experience working with suppliers and development partners.
Ability to take technical ownership and systematically develop complex systems.
Enjoy working across disciplines in a pragmatic, fast-moving team.
Your environment.
At Flux, we develop electric commercial vehicles in small, highly responsible teams. Our vehicles are already operating in the real world, on construction sites, in cities and in the daily operations of our customers.
That means decisions are made close to the product. Engineers take responsibility for their systems throughout the entire development cycle, from concept and testing through to issues seen in the field.
If you enjoy developing robust thermal and mechanical solutions, taking ownership and working in an environment where execution matters more than hierarchy, this role is a good fit for you.