Geoexchanger System for Buildings Heating and Cooling

Geothermal heat pumps (GSHPs), or direct expansion (DX) ground source heat pumps, are a highly efficient renewableenergy technology, which uses the earth, groundwater or surface water as a heat source when operating in heatingmode or as a heat sink when operating in a cooling mode. It is receiving increasing interest because of its potentialto reduce primary energy consumption and thus reduce emissions of the greenhouse gases (GHGs). The main conceptof this technology is that it utilises the lower temperature of the ground (approximately <32°C), which remainsrelatively stable throughout the year, to provide space heating, cooling and domestic hot water inside the buildingarea. The main goal of this study is to stimulate the uptake of the GSHPs. Recent attempts to stimulate alternativeenergy sources for heating and cooling of buildings has emphasised the utilisation of the ambient energy from groundsource and other renewable energy sources. The purpose of this study, however, is to examine the means of reductionof energy consumption in buildings, identify GSHPs as an environmental friendly technology able to provide efficientutilisation of energy in the buildings sector, promote using GSHPs applications as an optimum means of heatingand cooling, and to present typical applications and recent advances of the DX GSHPs. The study highlighted thepotential energy saving that could be achieved through the use of ground energy sources. It also focuses on theoptimisation and improvement of the operation conditions of the heat cycle and performance of the DX GSHP. It isconcluded that the direct expansion of the GSHP, combined with the ground heat exchanger in foundation piles andthe seasonal thermal energy storage from solar thermal collectors, is extendable to more comprehensive applications.