On February 27/28, the 8^th Annex 49 working meeting was held at the Free University in Brussels. The first day of the meeting was held in the building of Brussels environment, an office building with Leed certification, which was also visited in the frame of the meeting. The second day took place on the university campus. The objective of the meeting was the discussion of final results of the national Annex 49 contributions and the preparation of the deliverables. The meeting was attended by the countries AT, BE, CH, DE, EE and the US, NO and SE joined temporarily online by video conference.

F. Ochs of the Univ. of Innsbruck presented results of the modelling of two multi-family passive houses, which have been monitored for four years. By parallel simulation the energy demand was reduced year by years. By the validated model, optimisation of the system configuration have been investigated. Results indicate that the nZE balance is reached with optimisation of the system configuration.

C. Wemhoener of HSR Rapperswil presented results of a feasibility study, which has been performed for a neighbourhood in the south of Rapperswil. The neighbourhood offers good heat sources like the ground, ground water and lake water and a low temperature grid connected the waste water treatment plant as heat source. Based on these favourable boundary conditions the feasibility of three building projects to reach a net zero energy balance yielded the results that a nZE balance in the neighbourhood is possible with maximum installation of PV on the buildings and in the suited facades, and due to good feed-in tariffs and the buildings load, it can also be operated economically feasible.

C. Betzold presented an update on monitoring results of eight row houses near Nürnberg, which are designed as plus energy houses and connected by a grid. The central heat pumps reach high seasonal performance factors above 5 and the decentralised DHW heat pumps have monitored performance in the range of 4. In total the plus energy balance is reached.

Van D. Baxter gave a presentation as review of the different development steps of the integrated heat pump (IHP) concepts developed at the Oak Ridge National Laboratory (ORNL) and the Department of Energy (DOE). The development started already in 2005 with a concept study of HVAC technology for nZEB. Over the last 15 years, different prototypes of highly integrated heat pumps (IHP) for the building services space heating, domestic hot water, space cooling and dehumidification have been developed and investigated in field monitoring. The basic concepts are a ground-to-air and different air-to-air prototypes. The ground-to-air prototype has been introduced in the market in 2013, the air-to-air prototype have been further developed to a two-box concept, where functionalities are separated and a gas-engine driven prototype for areas with classical heat supply by gas boilers. In Annex 49 concluding field monitoring results of air-to-air IHP prototypes have been contributed.

Since Annex 49 is in the concluding phase, results are currently gathered and final reports are compiled. The final reports are expected to be published by the end of 2020. Final results will be presented at a workshop at the 13^th IEA HP Conference in Jeju, South Korea.