Design of a propane (R290) water-to-air reversible heat pump: performance optimization with 150g charge limit

The global effort to mitigate climate change has intensified the focus on reducing the environmental impact of refrigerants, promoting the adoption of low-GWP alternatives. European F-gas regulations have accelerated the transition toward sustainable refrigerants, highlighting the need for innovative solutions in heating and cooling systems. This thesis presents the design and development of a water-to-air heat pump prototype using propane (R290), a natural refrigerant characterized by its negligible Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP). Designed for residential applications and intended for indoor environments, the heat pump focuses on complying with the 150g refrigerant charge limit imposed by safety standards. The study is structured into three main phases: the dimensioning of refrigeration circuit components, the simulation of system behavior using Amesim software under steady-state and dynamic conditions, and experimental validation through prototype testing. The work demonstrates the feasibility of developing an efficient system with a reduced refrigerant charge, while maintaining high performance in terms of capacity and efficiency. Technical challenges related to the use of propane as a refrigerant are highlighted, requiring further research to optimize design and operational solutions. These findings represent a significant contribution not only to scientific research in the field of sustainable residential heat pumps but also to the industrial sector, providing a solid foundation for future commercial applications that align with environmental regulations.