The WPG-21-2 HT model is a model in the GEOS KRONOTERM geothermal heat pump series, which is designed for smaller residential buildings. With the WPG-21-2 HT heat pump, it can be used as the primary free source of groundwater, or the earth (geosonda or ground collector). The source of usage is set at startup. The heat pump is available in two versions. As WPG-21-2 HT / H 3F E, or WPG-21-2 HT / HK 3F E, which also allows cooling with a reversible process. More technical information can be found in the following documents.