Non-Refrigerant Based Cooling System for Vehicles

R134a is a high global warming potential (GWP) refrigerant used in a variety of cooling applications including vehicle cabin air conditioners. While several low GWP refrigerants have been developed to replace R134a, their flammability and hazards ratings make them incompatible with combat vehicle applications. As a result, the US Army seeks paradigm-shifting approaches to vehicle cabin cooling that achieve targeted cooling duty without the use of refrigerants. MantelÆs approach to addressing the ArmyÆs need for a non-refrigerant cabin cooling system utilizes an air cycle cooling system that is a radical improvement over conventional cabin cooling systems. The system operates using air as the working fluid, thereby eliminating GWP fluids,Ā the need for pressure vessels, and flammable materials. Mantel demonstrated the feasibility of its air cycle cooling system through its successful design, prototyping, and testing activities in Phase I. In Phase II, Mantel will build on Phase I success to refine and optimize system performance through design and fabrication of purpose-built components to address inefficiencies observed in the Phase I prototype system. The phase II prototype will demonstrate a cabin air cycle cooling system integrated with a HMMWV and providing the targeted 2-4 tons of cooling duty is required to achieve this shift and establish a path towards eliminating the ArmyÆs reliance on R134a.