23 September 2011
In recently years, the energy conservation equipment and the heat pump water
heater system bathe in attention as a response of the low carbonization society. It is
important to advance the energy saving and carbon dioxide (CO2) emission reduction in the
field of hot water supply which requires 1/3 of total energy consumption by households in
Therefore, reducing CO2 emissions from the energy use from this source is one of the top
priorities for Japan in order to mitigate climate change.
However, the introduction of heat pump water heater is facing a difficulty due to Japanese
housing situation. Typical Japanese houses in urban area are either apartment complex or
small houses proximately situated next to each other.
In an attempt to further diffusion of the heat pump water heaters, this paper describes the
research on the element components for the next generation heat pump water heater system and
the development of compact residential CO2 heat pump system.