The refrigerant has a significant influence on the operating characteristics (efficiency, heating capacity, operating envelope) of a Heat Pump. Due to political regulations (e.g., European F-Gas Regulation), the hydrocarbon R-290 (propane) is currently state of the art for new Heat Pumps within the building sector. In addition, many research studies deal with zeotropic mixtures based on low-GWP refrigerants to further improve the operating characteristics of heat pumps by utilizing the temperature glide of the mixtures. However, most investigations are simulation-based and their experimental validation is missing, yet.

Thus, we present the experimental results of low-GWP refrigerants (pure fluids and mixtures) in a brine-water Heat Pump testbench and compare the results to R-29 ...