The AReCoS story
Two problems hold heat pumps back: controls that fight, and frost that stops the heat.
AReCoS is building a heat pump designed to fix both: one built-in controller that sets the compressor, valves and fans together, and an air–water heat exchanger designed to keep frost to a thin layer and clear it while heating (patent pending). It started in a Michigan garage; its controller now holds U.S. Patent 12,768,557.
Problem 1 · Controls
It began with a bare workbench.
Ahmed Hussein, PhD, spent 12 years designing controls for automotive and aerospace machines. In heating and cooling equipment, each part is tuned and run as its own loop, even where parts pass each other a setpoint. The loops fight, and the machine pays in energy.
So he bought a workbench. The goal: one controller that runs a physics model of the whole cycle and sets everything together.
Show who built the frame
Badani, the best mechanic in the area, cut the steel frame and helped mount the coils, condenser and fans. He had never worked on a machine like this one, and built it anyway.
Real refrigerant needs real hands.
Most evenings ended with one question: does it make sense to the person holding the wrench? We still design by that rule.
Show who charged the system
Ten AC techs were called; most would not touch work they had never done. Doug Hines said yes, then wanted to know how the whole thing worked. He brazed the copper lines, pulled a vacuum and charged the system.
One clear box of wires.
On this bench, one controller ran a vapor-compression system in cooling from temperature sensors only, setting its compressor, electronic expansion valve, air blower and fan together.
Show who built the controller
Ahmed designed and instrumented the setup, wired the controller box and wrote its code.
That bench test appears in the AReCoS patent application, US 2024/0295337 A1, as FIGS. 4 to 7. It issued as U.S. Patent 12,768,557 on October 20, 2026, and the controller is being tested with Oak Ridge National Laboratory (ORNL), managed by UT-Battelle, LLC for the U.S. Department of Energy (DOE), under a research agreement (CRADA) with UT-Battelle supported by the DOE.
The bench grows up.
Show what changed
Insulated blower ducts went on top, and a proper power supply underneath.
Problem 2 · Frost
Then winter showed us the bigger problem.
Controls were only half the story. For decades, frost has forced air-source heat pumps to stop heating and defrost. A controller can time a defrost; keeping frost thin is the heat exchanger's job.
Show what the cold costs the grid
Their capacity also falls as it gets colder, so owners keep gas or electric backup beside them, and that backup electric heat drives winter peaks on the grid.
So AReCoS set out to build the heat pump itself: its controller built into the unit, not the cloud, and an air–water heat exchanger designed to keep frost to a thin layer and clear it while heating.
Same bench mindset, now designing much bigger machines.
We still start from the physics and test on real hardware. Own buildings, install equipment or build HVAC products? We would love to hear from you.
Let's talk.
Pilot sites for the AReCoS heat pump RTU, manufacturing partners for the first builds, the embedded controller for your refrigeration system, or the EV heat pump for your vehicle program.
Grand Rapids, Michigan 49546