Heat pump, domestic hot water, efficiency, space heating
Nowadays, one of the most important challenges in the residential sector is the efficiency improvement of the equipment and systems used for space heating (SH) and domestic hot water (DHW) production. The main objective is to reduce the consumption of fossil fuels and CO2 emissions in these applications. In this context, heat pumps are an effective technology as an alternative to boilers for SH and DHW production. However, the SH demand has a different temperature level than the DWH demand. Generally, the SH demand has a variable temperature level that depends on the type of distribution system (type of building) and the different climate conditions, while the DHW demand requires the storage of hot water at a temperature above 60 °C to prevent the presence of legionella. On the other hand, the performance of heat pumps deteriorates when working with high condensing temperatures. This paper presents a theoretical study of the performance of an air-to-water heat pump for simultaneous SH and DHW production, where the use of a desuperheater for DHW production and the condenser for SH production are analyzed. The study shows the optimization of the desuperheater capacity for a given SH demand. The performance of the heat pump is analyzed in terms of the COP and the capacities of the condenser and desuperheater. In addition, the heat pump performance was compared with the performance of two heat pumps (SH and DHW) for the same capacity in terms of compressor swept volume and heat exchanger sizes.