The article deals with modern energy-efficient systems for providing the microclimate of energy-saving buildings, consisting of geothennal ventilation with ground heat exchangers. The results of modern scientific research in this field are described. A schematic diagram of a geothennal ventilation system based 011 Rehau equipment is presented and a system of balance equations for the heat exchanger process in a ground heat exchanger is made, as well as analytical and graphical dependencies for detenninins the heat exchanger thermal efficiency for temperate climate conditions.