Interim results of IEA HPT Project 61 have been presented at the CISBAT 2025 Conference, which took place at the EPFL in Lausanne on Sept. 3-5, 2025.
Two contributions have been presented. The one was a collaborative paper regarding different integration options of heat pumps in districts derived for the ongoing simulation and monitoring projects. The University of Innsbruck investigate a block of four buildings as first phase of a 16-building districts which will be developed in four phases. The heating system and the groundwater heat pump are evaluated in detail by monitoring, which is also used to calibrate a system model. Results of three heating periods yielded the results of a very high heat pump performance in the range of 6, which, however, decreases to about 4.5 if the whole system is considered including losses and auxiliaries. Optimisation measures are derived as guideline for the next building phase.
At the SIZ Energy Plus, concept comparisons for the retrofitting of an existing district in Heide, Germany, by a centralized air-to-water heat pump connected to a high temperature heating grid has been accomplished. The favoured concepts also incorporated a large PV system, a CHP plant, a back-up boiler and thermal and electric storages. Simulation results confirm, that 50% of the heating demand can be covered with the heat pump by on-site electricity production. A higher fraction is possible, if additionally grid electricity is used.
At TH Nürnberg, a model retrofitting concept to climate neutral building level is developed by simulation and monitoring of a demonstrator. The blueprint can be transferred to similar building in the neighbourhood. Focus is set on building envelope retrofit and smart heat pump application with on-site PV generation and thermal and electric storages. Model predictive control is developed as system control. The concepts is also assessed regarding the economic viability.
A second presentation was dedicated to a boiler replacement in two larger multi-family houses with an integrated heat source of a smaller ground-source field for peak load coverage and an air-source used as base load and for ground regeneration. The system is also monitored, and the first year of operation proved the feasibility of the concept of the peak load coverage by the reduced ground probe field. Further evaluation regarding system concept comparison, optimized control and model validation of simulation models will be carried out in the future.
The papers will be published open access in the Journal of Physics: Conference Series probably by the end of November 2025.
Two contributions have been presented. The one was a collaborative paper regarding different integration options of heat pumps in districts derived for the ongoing simulation and monitoring projects. The University of Innsbruck investigate a block of four buildings as first phase of a 16-building districts which will be developed in four phases. The heating system and the groundwater heat pump are evaluated in detail by monitoring, which is also used to calibrate a system model. Results of three heating periods yielded the results of a very high heat pump performance in the range of 6, which, however, decreases to about 4.5 if the whole system is considered including losses and auxiliaries. Optimisation measures are derived as guideline for the next building phase.
At the SIZ Energy Plus, concept comparisons for the retrofitting of an existing district in Heide, Germany, by a centralized air-to-water heat pump connected to a high temperature heating grid has been accomplished. The favoured concepts also incorporated a large PV system, a CHP plant, a back-up boiler and thermal and electric storages. Simulation results confirm, that 50% of the heating demand can be covered with the heat pump by on-site electricity production. A higher fraction is possible, if additionally grid electricity is used.
At TH Nürnberg, a model retrofitting concept to climate neutral building level is developed by simulation and monitoring of a demonstrator. The blueprint can be transferred to similar building in the neighbourhood. Focus is set on building envelope retrofit and smart heat pump application with on-site PV generation and thermal and electric storages. Model predictive control is developed as system control. The concepts is also assessed regarding the economic viability.
A second presentation was dedicated to a boiler replacement in two larger multi-family houses with an integrated heat source of a smaller ground-source field for peak load coverage and an air-source used as base load and for ground regeneration. The system is also monitored, and the first year of operation proved the feasibility of the concept of the peak load coverage by the reduced ground probe field. Further evaluation regarding system concept comparison, optimized control and model validation of simulation models will be carried out in the future.
The papers will be published open access in the Journal of Physics: Conference Series probably by the end of November 2025.