The anticipated PFAS ban in the US by 2029 has created a need to evaluate alternative refrigerant solutions for automotive thermal management systems. This work compares three candidates—Propane (R290), Carbon Dioxide (R744), and R1234yf—through system-level testing and demonstration projects.
R1234yf remains the current industry baseline. Test results show that Propane (R290) delivers comparable efficiency while offering a significantly lower global warming potential. However, its flammability presents integration challenges, not present with R1234yf or R744. CO₂ (R744) demonstrated promising performance as well.
To address safety concerns with Propane, AVL developed mitigation measures including rapid leak detection, robust containment strategies, and optimized circuit layouts designed to reduce ignition risks. These countermeasures were validated in practice through the European Commission’s QUIET project. Within this program, a Honda B-segment electric vehicle was equipped with a Propane-based heat pump, thermal storage, infrared cabin heating, and lightweight materials. Testing under real-world conditions showed a 25% increase in driving range in cold conditions while maintaining passenger comfort [25,25]. An AI-based control strategy further improved system efficiency by coordinating thermal and energy management.
The findings demonstrate that Propane can be a feasible replacement refrigerant for electric vehicle applications if appropriate safety measures are implemented. CO₂ also remains a strong candidate, offering a cost-effective and PFAS-compliant solution. Together, these results contribute to the evaluation of sustainable refrigerants and provide guidance for future thermal system development in the automotive sector.