Sustainable domestic hot water production with heat pumping technologies will become the dominant energy demand in the domestic infra structure offering affordable smart storage opportunities.

IEA HPT Annex 46 is an international project on heat pumping technologies for Domestic Hot Water (DHW) under the IEA Technical Collaboration Program for Heat Pumping Technologies (TCP-HPT).

It is of great importance to work together with othe HPT Annexes and Annexes or Tasks from other TCP’s. At the recent 2018 – Sixth Working Meeting in Buchs – Switzerland, prof. Carsten Wemhöner, the Operating Agent from HPT-Annex 49 on nearly Zero Energy Buildings, was present, as well as the chairman for the HPT-ExCo Stephan Renz. In his presentation “Heat pumps for nearly Zero Energy Buildings – Design and integration”, Wemhöner showed us in a number of practical cases the importance of a good design of the Domestic Hot Water Heat Pump integrated in the energy systems of nZEB’s.

At the start of the Working Meeting held from 26th – 28th November in Buchs (Switzerland) on the invitation of NTB Interstaatliche Hochschule für Technik a number of other presentations were given.





The objective for the Annex is to analyse the information on hot water heat pumping technologies for the production of sanitary hot water in domestic and other applications. This information will be structured in such a way that leads to better understanding in the market by the end user and policy maker.

The work under the Annex will provide deeper insight into the potential of applying domestic hot water heat pumps using various concepts and systems for new as well as existing buildings by:

  • Reviewing available domestic hot water heat pumps and double function heat pumps making hot water next to space heating and/or cooling.
  • Reviewing the different systems for domestic hot water in their traditional and potential applications and gaining deeper insight in to the use of domestic hot water in order to create a solid basis for test and standardisation procedures.
  • Developing and validating models to enable an objective comparison of domestic hot water heat pumping technologies and other systems.
  • Making an overview of R&D, and sketching a scenario on the needed R&D. This information will be provided to industry players, institutes, and governments with the goal of achieving simple and low-cost solutions.
  • Data basing and where possible monitoring example projects to inform stakeholders of the viability of concepts.
  • Creating a web based information platform to serve countries participating in the Annex by publishing information on their market, legislation and policy.
  • Holding regular workshops
  • Collaborate with other related Annexes within the HPT-TCP or other TCP’s

Project manager and participating countries

Japan,  South Korea, United States, Canada, France, Switzerland and UK.

Netherlands is Operating Agent.

Visit the website for more information:



Field News

What happened before and since Rotterdam?

Some high lights Annex participants had 10 presentations at Rotterdam Conference A successful Workshop at Rotterdam Conference showed potential synergies...