This study evaluates the performance of geocooling in single-family houses across three French climates using dynamic co-simulation combining EnergyPlus and Modelica. A representative dwelling equipped with a single vertical borehole and radiant floor cooling is modelled, with borehole lengths sized according to national standards. Results show that geocooling effectively prevents summer discomfort in temperate climates (Strasbourg, Rennes) and significantly reduces overheating in a warm Mediterranean climate (Carpentras). Seasonal performance factors range from 33 to 44 when only primary pumping energy is considered. Cooling performance is mainly constrained by the 18 °C supply temperature limit imposed to prevent condensation rather than by ground thermal capacity. A parametric analysis shows that ground conductivity, heat pump COP, domestic hot-water production and building insulation primarily affect borehole sizing and therefore pumping power. Domestic hot-water preparation is the parameter with the strongest impact on comfort and on the seasonal ground energy balance, particularly in warm climates. Emitter choice also proves critical: radiant floors markedly enhance operative comfort and system efficiency, whereas fan-coil units can increase discomfort when controlled only by air temperature and reduce seasonal performance despite similar cooling capacities. • Geocooling ensures effective cooling in renovated homes across three French climates. • Geocooling achieves very high seasonal energy efficiency above 30. • Borehole sizing based on heating loads is a key factor in cooling potential.
Guilbaud et al. (Fri,) studied this question.