The thermally driven heat pump is a bit larger in comparison to a standard central heating boiler, but small enough to be installed at the same location as a boiler. This can be in the attic, basement or any other location inside or even outside the house. The heat pump can be connected to the existing hydronic supply and return lines. In case of installation under a roof, a roof feedthrough unit of 30×40 cm is needed to fit the air extraction unit.