New tap water heat pump using propane refrigerant.

A Danish manufacturer of tap water heat pumps has been producing appliances with HFC-134a for more than two decades. After the implementation of the EU ecodesign criteria and the EU energy labelling scheme for water heaters in September 2015, the demand for heat pump water heaters has been increasing. The interest in high energy classes and products using natural refrigerants is increasing as well. Two sizes of new products have been developed; a small unit with a 166-liter water tank using 140 grams of R290 and a bigger unit with a 270-liter tank using 350 grams of R290. This paper describes the construction of the heat pumps. Test results according to EN16147 are also provided. Moreover, the paper describes a method to handle the R290 refrigerant with a charge above 150 g. The method uses a ventilated enclosure in which the refrigeration system is placed.