View Full Version : New Technology

03-07-2004, 12:02 PM
hi guys.
Found this article. Might be of interest for some. Attached is the picture describes the process.


Growing CO2 Heat Pump Water Heater Market
The market for air-source heat pump water heaters (or air-to-water heat pumps) using carbon dioxide (CO2) has been growing rapidly in only 3 years since the 1st system was developed in 2001. The home use central water heater market is said to be sized at 3.5 million units/year, with the majority share being occupied by gas fired systems (LNG: 46%, LPG: 34%), while the share of electric systems accounted for only about 6% (a little more than 200,000 units), following the kerosene-fired systems (14%) (in fiscal year (FY) 2001). However, shipments of heat pump water heaters recorded some 37,000 units in FY 2002, and are estimated to have expanded to 75,000 ~ 78,000 units. It is also expected to reach 100,000 ~ 110,000 units in FY 2004, according to a maker's forecast.
The large demand for water heaters is partly attributable to the fact that Japanese people cannot be satisfied with taking a shower alone, and make it a custom to soak in the warm bathtub.
Since all electric power companies in Japan were allowed to use "ECO CUTE" (Kansai Electric's registered trademark) as a pet name for their heat pump water heaters using natural refrigerant CO2, it has been made widely known by the general public, coupled with the electric power companies' publicity backup and government's subsidy system. Home electric appliance makers are endeavouring to promote sales of "ECO CUTE" water heater systems, together with air conditioners, IH cooking heaters, dehumidifier- dryers for bathrooms and other appliances under the name of the so-called "all-electric home" scheme.
As the name indicates, at all-electric homes, all light and fuel energy is covered by electricity, thus making it possible to treat appliances simply and safely without causing a fire accident.
A heat pump system using CO2 was proposed by Prof. Gustav Lorentzen at NTNU/SINTEF* in the late 1980s.
Note: The Foundation for Scientific and Industrial Research at Norwegian Institute of Technology New concepts of high-side control called the "transcritical" cycle were devised by Prof. Lorentzen and his coworkers in their early patent applications.

The industrial group Norsk Hydro acquired all commercial rights to this technology in 1990. The CO2 technology developed at NTNU/SINTEF has been licensed to the system manufacturer through Hydro-SINTEF joint venture Shecco Technology. The first heat pump water heating system based on Shecco technology was made by the Japanese Denso Corporation in 2000.
The system (now called "ECO CUTE")
is marketed by a number of companies such as Mitsubishi Electric, Daikin, Sanyo Group, Hitachi AC Systems, Matsu****a Group, Toshiba Group, Corona (Denso-make), Chofu, etc.