IAA Mobility 2025 is a four-day event in Munich designed to showcase the automotive industry’s future, and when it comes to natural refrigerants in electric vehicles (EVs), several suppliers are looking to propane (R290).
Suppliers such as ZF and Nidec AMEC are developing thermal management modules (TMM) employing propane for EVs primarily using in-house components. The idea is that these packaged modules can be more compact and efficient than modules designed using a mix of parts.
ZF, perhaps best known in the auto industry for its transmissions, has been developing “TherMas,” its propane-based thermal management module, since 2021. The product is already in its second edition with a third version currently under development.
Nidec AMEC, which manufactures a wide variety of auto parts, brought a plastic model of a propane-based TMM to the show. This is the first TMM developed by the company, which bypassed HFO-1234yf and CO2 (R744) in favor of propane.
While German supplier Mahle is displaying a TMM built to use R1234yf, a low-GWP HFO that is PFAS (per- and polyfluoroalkyl substances), the company noted that it is “future-proof thanks to unproblematic change-over to R290.”
What’s driving propane’s progress
In addition to its thermodynamic properties, suppliers noted that cost was a driving force behind their decision to develop propane thermal management modules. Suppliers told NaturalRefrigerants.com they believe propane thermal management modules can reach price parity with those using R1234yf, currently the dominant refrigerant in electric vehicle mobile air-conditioning (MAC) systems.
When asked about CO2, suppliers said its high operating pressures and critical temperature of 31°C (88°F) were concerns. By contrast, R290 operates at similar pressures to R1234yf, which in the case of Mahle enables it to double dip, in a sense, on an existing product.
Suppliers were also keeping a close eye on a possible PFAS ban in Europe and its potential impact on the MAC space. That said, not all companies are waiting for regulators to push the issue, as evidenced by ZF and Nidec AMEC.
The waiting game
Regardless of whether its TMM is made of plastic or metal, all suppliers are waiting for regulators to decide if propane can be used in MAC systems. ZF believes a decision from the U.S. Environmental Protection Agency (EPA) could come as soon as 2026, in which case it said European regulators may then follow suit. In late 2024, ZF and other industry partners – including Ford – submitted an application to the EPA under its Significant New Alternatives Policy (SNAP) program to approve propane for use in mobile air-conditioning (MAC) systems.
After EPA approval, R290 will still need the support of automakers. This is because propane-based thermal management systems will have to address flammability concerns and the secondary-loop architecture required to keep the refrigerant out of the cabin.
Ford has come out in support of propane in EVs, with Angelo Patti, Product Development Engineer, calling it “the best global option for BEVs [battery electric vehicles] if safety is addressed.” Ford and automotive supplier DENSO are currently researching R290 thermal management systems for EVs.
Support for CO2
While propane was generating buzz at IAA 2025, CO2 is the only natural refrigerant approved for use in EV thermal management systems and its presence was felt at the show.
Valeo manufactures components for CO2-based MAC systems, and, while it didn’t display these products, NaturalRefrigerants.com was told it was showing potential customers an R744-based TMM currently under development. Valeo also said it’s developing a propane thermal management that will be ready by 2028.
Megmeet did have a CO2 thermal management module on display – which it brought to Auto Shanghai 2025 – and said it was already being used by an American manufacturer of electric school buses. The company also has an R290 e-compressor in its product portfolio.
