Start date:September 2015

End date: August 2018


The main objective is to investigate the potential of energy and emission of greenhouse gasses emission reduction by the increased implementation of hybrid heat pumps. Both through replacement of boilers, and by means of upgrading the systems’ efficiency in existing running installations.

The focus of this Annex will be on the residential sector, as well as the light commercial sector, where the market overview shows potential. The annex participants foresee justification to investigate this specific segment.

This objective should be achieved by:

  • (a) Market overview and system classification
  • b) Identification of market barriers and opportunities to allow sustainable market development
  • (c) Quantification of economic, environmental and energy performance of hybrid heat pumps in heating systems in a range of climates, countries and building types and building standards
  • (d) Identification of best practice cases in various applications
  • (e) From the objectives mentioned in (a), (b) and (c) identification of areas and applications with the:
    -­ Greatest environmental benefit
    -­ Best economics
    -­ Greatest market potential
    -­ Most suitable system configuration and control strategy
    -­ Highest importance in future energy systems
  • (f) Proposal on technical procedures to be included in future standards for determination of the performance of hybrid heat pumps and methods to evaluate primary energy consumption of the systems within this Annex
  • (g) Component and system modelling, simulation studies and sensitivity analysis for a wide range of operating conditions
  • (h) Comparison of hybrid heat pumps with other technologies in terms of their energetic and economic performance

Target audience

The target audiences of this annex are the manufacturers of hybrid heat pumps, engineers, planners, housing corporations, installers, (governmental) policy-makers, research scientists, normative bodies.

Project manager and participating countries

France, Germany, the Netherlands (operating agent), and the United Kingdom.

The Annex is still open for new participants. Contact your Executive Committe (ExCo) delegate and Peter Wagener.


The Annex has been structured into the following tasks:

      • Task 1. Market overview and system classification
      • Task 2. Performance evaluation and quality assessment
      • Task 3. Modelling and simulation of components and systems
      • Task 4. Standardized field test procedures and evaluation
      • Task 5. Knowledge dissemination and market support

Publication and result

The Annex deliverables will include

    • Deliverables task # 1:
    • Deliverables task # 2:
      • Report on testing procedure and testing experience
      • Recommendations for quality assurance measures
    • Deliverables task # 3:
      • Improved component and system models
      • Standardised boundary conditions
      • Report on system performance under different operating conditions, with different system configurations and control strategies (application matrix)
    • Deliverables task # 4:
      • Definition of standards for field testing of hybrid systems
      • Best practice for application of hybrid heat pumps
    • Deliverables task # 5: