Automotive parts supplier Nidec AMEC (Automotive Motors & Electronic Control) is working with OEMs to refine its propane (R290) thermal management module (TMM) sized for large passenger electric vehicles (EVs), according to R&D and Application Engineering Director Matt Stieber.
Nidec AMEC showcased a conceptual model of an R290 TMM for EVs at IAA Mobility 2025. At IAA Transportation 2026, Stieber, joined by Jens Hoffmann, Director of R&D at Nidec AMEC, discussed changes to the unit’s architecture, OEM considerations and development targets in an interview with NaturalRefrigerants.com. IAA Transportation was held September 15‒20 in Hanover, Germany.
“In our ground-up redesign, we made sure we could support all the required modes that most OEMs would likely want,” said Stieber. “We are creating the building blocks and trying to have the components available, similar to our traditional pumps, where customization is always required.”
For safety, the R290 unit indirectly heats and cools the EV’s cabin, battery and power electronics through a secondary water-glycol loop. The design includes an electric R290 compressor; four pumps serving the battery, radiator, condenser and chiller; and three actuators that operate the coolant valves to direct flow between the thermal circuits.
Nidec AMEC will manufacture the TMM’s main active components, including the compressor, pumps and actuators, according to Stieber. The company will work with its supply base to develop other TMM components for R290 operation, including leak-tight seals on the refrigerant side to minimize the propane charge and larger coolant-side components to accommodate higher flow rates.
Design adjustments: In collaboration with its sister company Embraco, Nidec AMEC redesigned the TMM to incorporate vapor injection, a compressor sized for real-world operating conditions and optimized system flow. “We are heavily using Embraco’s existing [R290] know-how to speed up everything on our side,” said Hoffmann.
- The company added a vapor injection option to support TMM operation in ambient conditions as low as −40°C (−40°F).
- The collaboration is developing an R290 compressor capable of handling foreseeable operating conditions, such as occupants running the EV’s air conditioning while fast-charging the battery. A proof-of-concept compressor is expected to be ready for laboratory testing by the end of 2026, Hoffmann said.
- Using simulation software, the company optimized flow channels and eliminated crossovers. It is also packing the refrigerant-side components as closely together as possible to minimize R290 charge, while accounting for compressor vibration.
What’s next: The company expects to have an R290 TMM prototype ready for bench testing in early 2027, with production targeted for 2029, according to Hoffmann.
- The company has created an interactive TMM display for upcoming trade shows, featuring a transparent manifold and LED lights to show flow direction and temperatures based on visitor-selected ambient temperature, occupancy and rapid-changing scenarios.
- The manufacturer will showcase the model at the SAE Thermal Management Systems Symposium, held October 6‒7 in Dearborn, Michigan, and at IZB, an automotive trade fair held October 27‒29 in Wolfsburg, Germany.
- Nidec AMEC’s next-generation development phase will focus on adapting the unit for commercial trucks. The company is already working with an OEM on such an application, Stieber said.
Market observations: Stieber shared his insights into EV TMM options, challenges and potential refrigerant transitions.
- He said some U.S.-based OEMs do not see a future for CO2 (R744) mobile air-conditioning (MAC) systems because of the higher operating pressures and temperatures required across the country’s diverse climates, as well as higher component costs.
- Legislation also shapes the market, he noted, questioning when R1234yf might be banned and R290 permitted for MAC units in different countries.
- “We see some customers developing indirect systems,” Stieber said. “They are taking a little performance hit, but they are preparing to handle any of the refrigerants – R1234yf, R290 and maybe even an intermediate step like R152a.”
Quotable: “We are designing an [R290] model that an OEM expert can look at and realize we’ve thought it through – that this makes sense,” Stieber said.
“We see some customers developing indirect systems. They are taking a little performance hit, but they are preparing to handle any of the refrigerants.”
Matt Stieber, R&D and Application Engineering Director at Nidec AMEC
