Assessing the decarbonization potential of new generation R290 high-temperature heat pumps for apartment buildings

Electricity driven heat pumps, especially the air-to-water ones, represent a key technology for the decarbonization of existing residential buildings. In particular, new R290 (propane) heat pumps represent a valuable solution for substituting existing combustion boilers in hot water heating systems at medium/high temperature without the refurbishment of the building envelope. In this work, the feasibility and potential energy savings that can be obtained by the application of high-temperature R290 heat pumps with respect to the condensing boiler technology when retrofitting existing residential buildings equipped with high-temperature heating systems is assessed. The results show that the energy savings are of the order of the 20 % in terms of non-renewable primary energy when R290 heat pumps are compared to the most efficient and up-to-date condensing boilers. Larger emission savings can be obtained when heat pumps are fed by green electricity.