22 May 2002
New controls such as variable speed compressors, pumps and fans as well as electronic expansion valves offer new possibilities for increased energy efficiency of heat pumps. These possibilities are first analysed through a literature survey that is divided into sections which each relates to the before mentioned controls. Thereafter optimisation of the condensation temperature for a brine-to-water heat pump is analysed. This optimal condensation temperature minimises the total power used by the compressor and the heating water circulation pump. The decrease in COP when deviating from the optimal temperature is asymmetric and non-linear. The decrease in COP will be larger for negative than for positive deviations from the optimal condensation temperature.