Wapler, JeannetteJeannetteWaplerGünther, DannyDannyGüntherBongs, ConstanzeConstanzeBongsMiara, MarekMarekMiara2024-07-012024-07-012020Note-ID: 00005812https://publica.fraunhofer.de/handle/publica/470591In newly built single-family houses in Germany, heat pump systems have become the most popular heating system. However, heat pump systems also operate reliably in existing buildings. This is a conclusion of a field test of heat pumps in existing residential buildings conducted by Fraunhofer ISE. This article gives an overview of the operation conditions of the application area, the energy-related performance of the systems as well as their impact on greenhouse gas savings.enheat pumpsexisting buildingsrenovationsingle family housesfield trialmonitoringjournal article