07 September 2016
Since the mid of the 1990ties low energy buildings with a significantly reduced energy consumption down to ultra-low energy standard (typical space heating energy need of 15 kWh/(m2a)) have been realised.
Based on the political strategies for the building sector in terms of meeting the Kyoto targets, the buildings concepts are currently extended to derive a nearly zero energy balance, which requires on the one hand an energy-efficient building envelope and on the other hand energy-efficient building system technologies amended by an on-site renewable energy production.
IEA HPT Annex 40 is to investigate heat pumps for the application in nearly zero energy buildings. Due to the unique features of the heat pump, the application in nearly zero energy buildings can be particularly beneficial. Besides the high performance of the heat pump in combination with adapted systems of low supply temperatures, which can be installed in buildings with high performance envelope due to the low space heating loads, also the integration options of heat pumps with other building technologies can be an advantage of the heat pump in these buildings.
In Task 4 of the IEA HPT Annex 40, field monitoring projects of heat pumps in high perfor-mance buildings as well as in nearly or net zero energy buildings have been accomplished. Results of the field testing are evaluated regarding:
• Performance of the heat pump operation in nearly or Net Zero Energy Buildings
• Verification of the nearly zero energy balance
• Optimisation potentials for the heat pump operation in low or nearly zero energy buildings
• Performance of the heat pump in multifunctional operation for different building services
• Controller settings in order to improve heat pump operation
In some of the projects, also evaluations of the self-consumption were accomplished, both for residential and for office use. Moreover, tests were made to shift the heat pump operation to times with on-site PV generation. It was found that in residential multi-family use, the self-consumption can be increased by 10-15% to values of more than 30%, which is a high value compared to other evaluations for residential use. Furthermore, it was found that with office use, even values around 40 % self-consumption were reached without particular load shift due to better load match of the on-site generation with office use.
This report on Task 4 covers the results of the different field monitoring projects performed in Annex 40, which are:
• Grid integration of nZEB in Canada
• Long term monitoring of low energy office buildings in Germany
• Demonstration project of an Eco city with demand response in Japan
• Field monitoring in the frame of the “Energiesprong” project to retrofit buildings by the “net zero on the meter” concept in the Netherlands
• Field monitoring results of the first pilot and demonstration nZEB in Norway
• Field monitoring of two nZEB buildings according to the MINERGIE-A® standard with residential and mixed residential and office use in Switzerland