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IEA HPT Annex 50 Final Report – Heat Pumps in Multi-Family Buildings for Space Heating and Domestic Hot Water

IEA HPT Annex 50 Executive Summary – Heat Pumps in Multi-Family Buildings for Space Heating and Domestic Hot Water

IEA HPT Annex 50 2-page Summary – Heat Pumps in Multi-Family Buildings for Space Heating and Domestic Hot Water


Particularly the following issues will be elaborated:

  • How to stimulate an increased use of heat pumps in multi-family houses
  • Enhancement of heat pump systems and/or heat pump components for their adaptation in multi-family buildings (scalable power range, high-temperature heat pumps, double stage compressors, inverter technology, etc.)
  • Development and demonstration of concepts for application of heat pumps in energetically renovated buildings and in buildings without improved building envelope
  • Finding the optimal bivalence temperature for bivalent or hybrid systems
  • Demonstration and monitoring of technical solutions (in prototype or market phase)
  • Identification of needs on the characteristics of HP components and figuring out, which are neither fullfilled by market available products nor a scope in ongoing research and development projects; making recommendations for future research and development needs
  • Presenting recommendations for the optimal (multi) heat source and operating mode (fuel driven, electric driven, hybrid) solutions depending on building type and ecologic-economic situation and climatic zone (weather, design temperature)
  • Close cooperation with companies in all relevant technology areas, as well as with the housing societies


The building sector plays a significant role for the energy consumption in every country. New domestic buildings are often built with an envelope and heating system aimed at a low energy usage. And with a potential for application of renewable energy technologies, such as heat pumps. For multifamily buildings, the challenge to apply heat pump technologies and renewable energy is more complex due to technical aspects as well as economical. While in some countries multifamily houses are often owned by local cities, communities or housing corporations, in other countries ownership is private and divided into separate flats.

Multifamily houses bring along a range of heat demand characteristics. Firstly the share of domestic hot water demand on the overall heat demand varies due to varying building standards as well as different climates. Secondly, the temperature level of the heating system is influenced by these aspects. As well as by the installed heating transfer system. Henceforth, dealing with the variety of heat demand characteristic bears the challenge on the way to a broader spread of heat pumps in multifamily buildings.

Heat pumps – those powered by electricity, as well as those using fuel – have a significant potential for reducing the specific CO2 emissions for the heat supply in multifamily buildings. This potential is connected with special demands on both sides: the domestic hot water preparation and the heat transfer system (heat sink) as well as the utilization of environmental energy at site (heat source).

Contact Person

Mr Marek Miara,