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6th Annex 49 working meeting held at the University centre of Uni Innsbruck, Obergurgl, Austria

The 6th IEA HPT Annex 49 working meeting was held at the University Center of the University of Innsbruck in Obergurgl, Austria on February 25-27, 2019. It has been attended by the seven countries AT, CH, DE, EE, NO, SE and the USA. Due the vicinity of the site all participating institutions from Austria, the Austrian Institute of Technology AIT, the Institute of Thermal Engineering IWT of TU Graz and the Unit energy efficient building of the University of Innsbruck UIBK have attended the meeting.

On the first meeting day an update of the national contributions of the participating countries on the Task 2 on the integration of heat pumps in nZEB, Task 3 dedicated to the monitoring and prototype development and Task 4 on the design and control of heat pumps for nZEB application has been discussed.

For instance the contributions of the three Austrian institutions have been presented in more detail and are related to all Annex 49 Tasks.

At AIT two projects related to a group of buildings with different heat sources and connected by grids and storages as well as a large office building are investigated with regard to commissioning and control improvement, which is linked to monitoring and simulation work. Lessons learned from the buildings are that an integral planning including different part load scenarios and the thorough commissioning phase facilitate the building operation and monitoring helps to optimise the system performance in the operation phase. Commissioning should be a multi-stage process, where systems are commissioned in the right operation phase, e.g. the cooling system in summertime.

At IWT of TU Graz one project deals with the integration of the building thermal mass in order to increase self-consumption of a heat pump and solar PV system combination. Interim results of the simulation confirm that by the different measures of heat storage in the building thermal mass, an adapted DHW operation during daytime and adapted capacity-control of the heat pump to the PV yield the grid electricity consumption can be significantly reduced.

Another project comprises the development of a facade integrated cooling system, which is simulated and monitored in two test boxes on the University campus. First monitoring results confirm that the cooling can reduce indoor temperature by 3-6 K compared to a reference test cell.

At the UIBK two multi-family social housing projects on passive house level are monitored and simulated in detail in order to approve the nearly zero energy balance and identify and implement optimisation potentials found in the monitoring and simulation. By the implemented optimisation of the heat pump operation and control, the electricity consumption could be reduced from 43 MWh to 35 MWh. Further optimization measures will be implemented and simulations indicate that the nearly zero energy balance can be reached.

After the presentation on the first day simulation models of an nZEB which is modelled on different simulation platforms has been presented and informations on the different models have been exchanged. On the second day, organisational issuses have been discussed, among others the structure of deliverables and reports of the different Annex 49 Tasks.

The meeting was concluded by a technical tour to the labs of the unit for energy efficient buildings at the University of Innsbruck.