SUMMARY
In this research the technical designing of energy efficient heating system with vertical-borehole heat pumps for institutional buildings was performed. The local government would like to change the old gas boiler-based heat producing system to up-to-date, environmental friendly equipment with the financial support of the European Union. The payback time was calculated and environmental calculations were achieved with carbon dioxide saving by various conditions that were also achieved during the research project. The results show that the heat pump system also provides a significant reduction of environmental load, in addition to significant energy savings. The amount of calculated savings justifies the environmental friendliness of heat pump systems.