Interpretation of rock mass thermal conductivity at the design stage of heat pump installation and its impact on system efficiency (COP)Michał Kaczmarczyk, Magda Kaczmarczyk, Konrad Thürmer and Magdalena KlichE3S Web Conf., 66 (2018) 02007DOI: https://doi.org/10.1051/e3sconf/20186602007