German automotive components manufacturer ZF has found that its propane (R290)-based TherMaS thermal management system can increase the driving range of electric vehicles (EVs) by up to 30%, compared to an R1234yf-based system of similar capacity.
The company attributes this gain to optimized thermal management and efficient use of waste heat from the vehicle’s drivetrain, a breakthrough especially effective in winter and other extreme conditions. The extent of improvements to driving range depends on operating conditions; however, the system also performed well in other real driving scenarios, it added. ZF did not state which EV was used to test TherMaS.
“Thanks to the superior capabilities and easy-to-integrate design, our customers can expect better e-drivetrain performance and a longer electric range without compromising on comfort,” explained Otmar Scharrer, Senior Vice President R&D of Electrified Powertrain Technology at ZF.
Market ready: While the system is not yet commercially available, ZF has said TherMaS is “ready for the market” pending regulatory approval for the use of propane in mobile air-conditioning (MAC) applications.
- In late 2024, ZF and other industry partners submitted an application to the U.S. Environmental Protection Agency (EPA) under its Significant New Alternatives Policy (SNAP) program to approve propane for use in MAC systems.
- A positive decision is expected in 2026, which could lead to similar approval in Europe, Karin Markenstein, ZF’s Head of Corporate and Marketing Communications, told NaturalRefrigerants.com.
- If EPA approval is granted in 2026, ZF has said it believes its TherMaS system could be on the market before 2030.
“There is very high interest from the OEM side for our thermal management system,” added Markenstein. “However it all hinges on the propane approval before getting an official order for series production.”
Product development: ZF presented the first version of its TherMaS system in a prototype EV in 2023, which was based on the Porsche Taycan. Since then, ZF has reengineered the system for better performance and integration, simplifying its electronic architecture and reducing refrigerant charge from 290 to 150g.
- The manufacturer has also improved control of the secondary water and glycol circuits for the vehicle’s motor, battery and other electronics. A lighter, more compact housing now enhances space efficiency and installation flexibility and reduces thermal losses.
- The unit can offer cooling and heating capacities of at least 10kW (2.8TR) in ambient temperatures of −25 to 35°C (−13 to 95°F).
- It will be available in three performance classes to cover a wide range of applications and its modular design enables integration into a variety of vehicle platforms.
“To our knowledge, no propane-based thermal management system was available in a demo vehicle before our system was presented to the industry at the IAA 2023 auto show,” said Markenstein.
Industry context: As the adoption of EVs increases, the market for thermal management systems is expected to grow at a CAGR (compound annual growth rate) of more than 16% between 2025 and 2034.
- Thermal management is one of the most energy-intensive systems in an EV, playing a critical role in both passenger comfort and the efficiency and longevity of the battery and power electronics.
- HFO R1234yf is used in the majority of EV thermal management systems today. However, automakers are highly likely to opt for natural refrigerants like propane or CO₂ (R744) due to the potential prohibition or regulation of per- and polyfluoroalkyl substances (PFAS) such as R1234yf in Europe, according to consulting firm Ducker Carlisle.
- Other EV component manufacturers, like French company Valeo, are also preparing for the PFAS ban by investing in the development of natural refrigerant-based technologies.
Quotable: “Propane is a natural non-toxic refrigerant, which is important from a health perspective,” explained Markenstein. “It has excellent thermodynamic properties, operates at reasonable pressure levels and is cost-effective, comparable to those of commonly used refrigerants today. When we look at the building sector, all high-performance heat pumps are based on propane.”
