Mechanical Engineer - Thermal/Refrigeration Systems, Advanced Engineering
$200k - $300k USD
About Fluidstack
At Fluidstack, we’re building the infrastructure for abundant intelligence. We partner with top AI labs, governments, and enterprises - including Mistral, Poolside, Black Forest Labs, Meta, and more - to unlock compute at the speed of light.
We’re working with urgency to make AGI a reality. As such, our team is highly motivated and committed to delivering world-class infrastructure. We treat our customers’ outcomes as our own, taking pride in the systems we build and the trust we earn. If you’re motivated by purpose, obsessed with excellence, and ready to work very hard to accelerate the future of intelligence, join us in building what's next.
The Role
We are developing a direct current air cooled chiller program to support our next generation AI data centers. As a Mechanical Engineer focused on Thermal/Refrigeration Systems, you will own the thermodynamic design of our chiller platform. You will be responsible for refrigeration cycle optimization, compressor selection and integration, heat exchanger sizing, and overall thermal performance. This role requires deep expertise in vapor compression refrigeration systems and the ability to translate thermal requirements into production ready designs.
What You Will Do
Lead thermal modeling and simulation of the refrigeration cycle, including compressor staging, superheat / subcooling control, and part load performance optimization
Own the selection and integration of compressors
Design and specify evaporators, condenser coils, and heat exchangers to meet target COP / IPLV specifications
Develop P&IDs with all control loops, safety interlocks, and instrumentation for the refrigeration system
Specify electronic expansion valves, refrigerant piping, and flow control components
Work closely with controls engineering to define control strategies for compressor staging, capacity modulation, and fault handling
Support refrigerant selection and regulatory compliance (R-1234ze(E) for EPA AIM Act compliance)
Lead performance testing and validation, including full-load and part-load testing across operating range
Drive certification efforts including ASHRAE 15, ASME B31.5, and UL 1995 compliance
What We Are Looking For
5+ years of experience in refrigeration system design, chiller development, or HVAC equipment engineering
Deep understanding of vapor compression refrigeration cycles, including centrifugal compressor performance characteristics
Experience with thermal modeling tools (EES, CoolPack, or similar) and refrigerant property databases
Hands on experience bringing refrigeration equipment from concept through prototype to production
Familiarity with low GWP refrigerants and evolving refrigerant regulations
Experience with ASHRAE standards (15, 34, 90.1) and UL certification processes
Strong analytical skills and comfort with ambiguity in early-stage product development
BS or MS in Mechanical Engineering or related field
Nice to Have
Experience with magnetic bearing compressor platforms
Background in data center cooling systems or high density thermal management
Experience with DC powered equipment or variable speed compressor drives
PE license
The salary range for this position is $200,000- $300,000 per year, depending on experience, skills, qualifications, and location. This range represents our good faith estimate of the compensation for this role at the time of posting. Total compensation may also include equity in the form of stock options.
We are committed to pay equity and transparency.
Fluidstack is an Equal Employment Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, sexual orientation, gender identity, disability and protected veterans’ status, or any other characteristic protected by law. Fluidstack will consider for employment qualified applicants with arrest and conviction records pursuant to applicable law.
You will receive a confirmation email once your application has successfully been accepted. If there is an error with your submission and you did not receive a confirmation email, please email careers@fluidstack.io with your resume/CV, the role you've applied for, and the date you submitted your application-- someone from our recruiting team will be in touch.