Ioan Sarbu is a professor and head of the Department of Building Services Engineering at the Polytechnic University of Timisoara, Romania. He obtained a diploma in Civil engineering from the "Traian Vuia" Polytechnic Institute of Timisoara in 1975 and a Ph.D. degree in Civil engineering from the Timisoara Technical University in 1993. His main research interests are related to refrigeration systems and heat pumps. He is also active in the field of solar energy conversion, water distribution systems and numerical simulations and optimizations in building services. Additionally, he is a member of the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers, IAHR (International Association for Hydro-Environment Engineering and Research), and AIIR (Romanian Association of Building Services Engineering). He has published over ten books, several book chapters, about a hundred articles in indexed journals and more than fifty articles in proceedings of international conferences.

He is also author of five patent certificates and of up to twenty computer programs. Prof. Ioan Sarbu Polytechnic University Timisoara Romania ioan.sarbu@upt.ro Calin Sebarchievici is a lecturer in the Department of Building Services Engineering at the Polytechnic University of Timisoara, Romania. He obtained a diploma and a Ph.D. degree in Civil engineering from the Polytechnic University of Timisoara in 1998 and 2013, respectively.

His research is focused on the energy efficiency of building services and equipments such as heat pumps, circulating pumps, and solar thermal and photovoltaic panels. He is a member of the GEOEXCHANGE Romanian Society and AIIR (Romanian Association of Building Services Engineering). Also, he has several indexed journal articles and international conference proceeding publications.