Press Release Back Number(2004)

Development and Sale of EcoCute "Atatame Jozu" with Bathroom Heating and Drying Functions
- Multifunctionality and Better Energy Efficiency Achieved by New Two-Way Heat-Controlling System -

March 9, 2004

Chubu Electric and Hitachi Air Conditioning Systems Co., Ltd. have jointly developed "Atatame Jozu," a multi-functional natural refrigerant (CO2) heat pump water heater (EcoCute*1). Hitachi Air Conditioning Systems will start marketing the product on April 1. Marking a first for the power industry, the new EcoCute heater includes the following functions: "the supply of hot water," "bathroom heating and drying," and "bath reheating."


  1. *1 "ECoCute" is the nickname given to natural refrigerant heat pumps by power companies and water heater manufacturers.

Bathroom heating and drying devices are in great demand because they help protect elderly people from dramatic changes in temperature, reduce the build-up of mold in bathrooms, and ensure that laundries do not become damp. It has, due to the large amount of energy required to perform such jobs, been difficult in the past to develop a multifunctional EcoCute that could heat and dry bathrooms and reheat a bath at the same time.

We have, however, thanks to the development of a two-way heat controlling system, succeeded in making a water heater that has both bathroom heating/drying and bath reheating functions. In addition, the new product is less expensive to run and conserves more energy than conventional water heaters.

The two-way heat controlling system is more economical and efficient in its operation because it separates the hot-water storage tank into two sections. Its upper part generates heat at a higher temperature (90°C) than its bottom part (65°C). The upper part provides heat for bathroom heating/drying and bath reheating, both of which consume a large amount of energy, whereas the bottom part supplies heat to make hot water for baths. The equipment, by using off-peak power, reduces operating costs by about 80% compared with gas water heaters that have bathroom heating and drying functions. Our goal is to develop equipment that can be installed at fully electrified homes, giving their residents a healthier and better quality of life.

1. Product Features

(1) Fully equipped with bathroom heating/drying and bath reheating functions.
The two-way heat controlling system regularly provides high-temperature heat (90°C), enabling the new EcoCute to heat and dry the bathroom and reheat the bath.
(2) Highly cost effective
The product is energy efficient (COP 4.17*2), and represents an 80% savings on operating costs compared with gas water heaters that have bathroom heating and drying functions because it uses off-peak power.
  1. *2 "COP": hot-water supply capacity divided by power consumption. The higher the figure, the greater the level of energy conservation.