07 September 2016

Heat Pump Concepts for Nearly Zero-Energy Buildings: Final Report – Task 2: Case studies on building system technologies for nZEB

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)) or even net zero energy consumption (on an annual basis by an integration of on-site renewable energy systems) have been realised. Based on the political strategies for the building sector in terms of meeting the climate protection targets, the building 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 building envelopes 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 application in these buildings.
Task 2 is dedicated to identify promising concepts for the further development of system configurations and analysis of technologies suitable for different applications in nZEB. Concepts shall be compared based on energy performance and cost to approve the feasibility of heat pump solutions for the application in nZEB.
For this evaluation case studies for the assessment of different system solutions for the energy supply of nZEB have been accomplished. Thereby, the following items are addressed:
• The role of heat pumps in nZEB under the boundary conditions of different countries
• Favourable technology combinations to reach the nZE balance cost-effectively
• Comparison of performance and cost for different system configurations in residential and office buildings
• Assessment and ranking of system solutions for different applications and boundary conditions
• Analysis of integration options of heat pumps with other building system technology, e.g. solar assisted heat pumps
• Development of design tools for the generator and emission system
This report on Task 2 covers the case studies performed under IEA HPT Annex 40. The results presented in this report summarise the:
• Case study in Canada for heat pump application in residential single- and multi-family as well as in office buildings
• Case studies in Finland and Sweden for residential single- and multi-family buildings
• Case study to reach nZEB in office buildings in Japan with pronounced air-conditioning loads
• Development of a design tool for heat pump and back-up system for optimised cost and minimised CO2-emission at SINTEF Energy in Norway
• Development of a design tool for the comfort evaluation at the Center of Environmental Energy Engineering (CEEE) at the University of Maryland
• Case study in Switzerland of technology comparison for MINERGIE-A® residential and office buildings