Energy Efficiency in Fixed, Staged and Variable Capacity Ground Source Heat Pumps

Abstract

This paper presents the results of a study carried out as part of a European project titled Ground-Med “Advanced Ground Source Heat pumps in the Mediterranean climate” which aims at demonstrating the efficiency of ground source heat pumps (GSHP) in mild weather climates like the Mediterranean, obtaining a seasonal performance factor (SPF) for the integrated system greater than 5. In order to achieve this goal, it is necessary to design heat pumps as efficient as possible. The work presented in this paper consists in a theoretical study carried out for the development of a high efficiency ground source heat pump prototype for heating and cooling in one of the demo sites of the Ground-Med project, located in an institutional building at the ‘Universitat Politècnica de València’, Valencia, Spain. The design will be based in the optimal selection of components for the ground source heat pump application. Different compressor technologies available in the market will be evaluated: fixed, staged and variable capacity compressors, and the seasonal performance factor for both winter and summer will be evaluated for each configuration of compressor considered. Results show that the best solution corresponds to the use of two compressors in tandem.