Home 2018-12-20T20:33:10+00:00

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).

Working together with other Annexes

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:

  1. Introduction to the Interstaatliche Hochschule für Technik – prof. Stefan Bertsch
  2. Swiss policy on R&D for Heat Pumps – Stefan Renz (Chairman of the HPT ExCo)
  3. Test procedures for DHW HP – Mick Eschmann (NTB)
  4. Multi-criteria Air Source Heat Pump Water Heater optimization combining optimized thermodynamic performance and control – Mihai Radulescu (EDF)
  5. Example projects with DHW – Charles Geelen (Infinitus)


  1. A presention on the Annex was held by Cordin Arpagaus at the Swiss IEA Networking event.
  2. New Papers published by Annex participants on PUBLICATIONS page.
  3. Rocky Mountains Insititute publishes interesting report on Zero Energy Houses in the USA with a clear statement about Heat Pump Water Heaters
  4. 25th IIR Conference ICR 2019 will be held from 24th – 30th August 2019 at Palais de Congrès de Montréal. At the Conference a special workshop will be organized by the Annex 46 on Domestic Hot Water Heat Pumps. The focus will be on R&D and future developments.
  5. A number of Example Projects have become available in various of categories. Also three nice videos under the page ‘Example projects with CO2 as refrigerant‘.
  6. The PRESENTATIONS from the Annex workshop in Tokyo are now available, focusing on R&D in a number of participating countries
  7. 13th IEA Heat Pump Conference will be in 2020 in South Korea on Jeju Island. The abstract submission system for the Conference will be open from January, 2019. The final date for submission of anstracts is May 15, 2019.
  8. All papers from the 12th IEA Heat Pump Conference on Domestic Hot Water can be downloaded as ZIP-file.

Heat pumps can be used to heat water in a very efficient way and major CO2 and energy reductions can be realized by using heat pumping technologies for water heating.