HPS is the HiRef range of air-to-water multipurpose reversible heat pumps designed for operation in very cold climates. The use of compressors with EVI steam injection technology allows the production of hot water up to 65 °C and operation with outdoor temperatures down to -20 °C. This is combined with special focus on Low Noise (the “Low-Noise” silenced version is supplied as standard) and the use of different refrigeration circuit architectures to meet the needs of many different system applications.