It is now highly likely that with the rise in fuel, gas and electricity prices, groundwater deposits will become the third primary source of renewable energy, alongside photovoltaic cells and wind turbines. These deposits are characterized by unlimited clean and environmentally friendly energy with constant parameters independent of the fluctuations of wind and solar energy. This paper presents innovative low-carbon solutions for converting groundwater energy into heating and cooling energy in FCH HVAC. A good example of a significant reduction in CO2 emissions achieved by this technology is a study describing the system implemented in the Integrative Sports and Recreation Center in Łomianki. New installations for the FCH technology in the abovementioned center will reduce the consumption of heating and cooling energy as well as CO2 emissions by at least 50%. The aim of this article was to present the energy from underground waters and how to use it in HVAC installations. The authors show a new direction for the use of forgotten energy that is not only available in unlimited quantities at all latitudes but also has a very small carbon footprint and can significantly reduce CO2 emissions.