R-290 in particular has become one of the standard refrigerants in detached and semi-detached houses alongside R-410A and R-32. Currently, more than 50 market players already offer Heat Pumps with R-290. It will be shown how the selection of the refrigerant affects Heat Pump efficiencies of individual systems by the large-scale analysis of product data but also their influence on the overall efficiency on annually installed Heat Pumps by analysing the share of R-290 Heat Pumps being subsidized within the German BEG EM Heat Pump funding and their efficiencies. The continuation of this development on the demand side depends to a large extent largely on the development of further fields of application in which R-290 Heat Pumps are available as products. These are mainly applications installed ...