Goals achieved for the Annex

Although the goals for this Annex may be achieved, a lot of work still is ahead of us to come to full deployment of the technology!

A new Annex is the next step in this process.


The work under the Annex provided insight into the potential of applying heat pump water heaters.

A number of main topics is reported upon:

Next to these there is a number of example projects, documented in factsheets.


The IEA TCP – 4E Mapping and Benchmarking has made extensive study on water heaters for domestic applications. The Final Report states that switching from technology gives a huge potential in energy conservation far greater than increasing the performance of existing technologies. As an example, a switch from the worst performing gas storage water heater to the best heat pump model would reduce annual energy consumption by almost 7 MWh per water heater. However, traditionally, policy makers have been reticent in pursuing policies that would drive switching of product type, even where technology neutral policy measures have been deployed.

Main conclusions

The share of Domestic Hot Water (DHW) production in the total heat consumption of the building has increased while in general the temperature of DHW is higher than the temperature for space-heating. Thus DHW production has become a dominant factor in heating systems for new buildings. The same is the case for the ‘deep’ renovation of existing buildings.

Although there are some noticeable successes in the market developments, heat pump water heaters are still having a relatively small niche market share with a much larger potential. Traditionally however policy makers are reluctant to make choices, thus except for Japan in the past with the Top Runner program, there seems to be no specific support for market development of heat pump water heaters.





Field News

13th IEA Heat Pump Conference

Large number of presentations on HPWH related topics Refrigerants 031 – Bo Zheng (Gree), Experimental Investigation on One-time Heating R32...