07 September 2016

Heat Pump Concepts for Nearly Zero-Energy Buildings: Final Report – Project outline and summary of main results

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.
These building concepts recently show strong market growth in different European countries. Based on this development, the objective of the political strategies in Europe, North America and Japan focus on so-called nearly or Net Zero Energy Buildings as next step of high performance buildings as part of the strategies to achieve climate protection targets in the frame of post Kyoto-process.
Due to the following features, heat pumps seem very suited for the application in nearly zero energy buildings:
• Heat pumps are highly energy-efficient with adequate system design, in particular in energy- efficient buildings with low loads and low supply temperatures, reducing thereby the need of on-site energy generation in order to meet the nearly zero energy balance
• Heat pumps can cover multiple building services of space heating, domestic hot water production, space cooling and dehumidification as needed even in simultaneous operation
• Heat pumps have good integration options with other building technologies like the ventilation system or solar components in the building envelope
• Heat pumps are often one of the main electricity consumers and thus offer potential of load shifting and demand response in order to optimise local use of on-site generated electricity or offer operation reserve to connected grids
In accordance with these features, heat pumps are already quite established in built pilot and demonstration nZEB.
The IEA HPT Annex 40 entitled “Heat pump concepts for Nearly Zero Energy Buildings” deals with the application of heat pumps as core component of the heating, ventilation and air-conditioning HVAC system in nearly or Net Zero Energy Buildings (nZEB or NZEB, respectively).
The main objectives of the IEA HPT Annex 40 are thus an evaluation and comparison of system solutions in order to characterise the role of heat pumps in nearly zero energy buildings and further develop heat pump systems for the application in these buildings, leading to the following objectives:
• Characterisation of the state-of-the-art of nZEB in the different participating countries
• Assessment and comparison of the energy performance of different system solutions for the application in nZEB in form of case studies
• Development and lab-testing of new system solutions of integrated heat pumps for the application in nZEB
• Accomplishment and evaluation of field tests of new developments and marketable systems in order to characterise the energy balance and the system performance
This report gives an introduction to the political background and the state of the definitions and labels of nearly Zero Energy Buildings and an outline of the Annex work and the national contributions. The main results of the IEA HPT Annex 40 are summarised.