Critical discussion on the challenges of integrating heat pumps in hydronic systems in existing buildingsCholewa, Tomasz; Bejan, Andrei-Stelian; Miara, Marek; Schauer, Christian; Kosonen, Risto; Borodinecs, Anatolijs; Bogdanovičs, Raimonds; Amanowicz, Łukasz; Vering, Christian; Siuta-Olcha, Alicja; Kurnitski, JarekEnergy2025 / art. 136158 https://doi.org/10.1016/j.energy.2025.136158