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Keywords

Y2

deviceZ4

electricity

S5

renewable energy

LTechnical Services

Heat Pump and Thermal Storage Technology Center of Japan

Air/Heat Pump Water Heater with Natural-RefrigerantFeaturesu A high efficient water heating system that uses heat in the air to boilwater.
- Developed in 2001.
- Achieves heat energy for water heating with less than 1/3 of theelectricity.
u Low running costs- This highly efficient system enables less power consumption andrunning costs can be significantly reduced by utilizing electricity
during cheaper times.
u Dramatic reduction of household energy consumption- Approximately 30% of total energy in an average Japanesehousehold is used for the hot water supply. Energy-saving water
heaters contributes significant energy conservation.
- Dramatic CO2 emission reductions are achieved when compared toconventional fossil-fuel burning water heaters.
u Eco-friendly natural refrigerant (CO2 refrigerant) is used.

Basic Concept or Summary
・ The “Eco-Cute” water heater uses heat in the air. It’s officially known as Heat Pump Water Heater with
Natural-Refrigerant.
・ Like hot and cold, untouched and unused heat energy in the air and water abounds. Heat pumptechnology utilizes this thermal energy for various uses such as air conditioning and hot water/watersupply.
・ Heat in the air and water—yet unutilized—is used instead of fossil fuels, making this water heater
energy-efficient.

・ On sale since 2001, the Eco-Cute is the world’s first heat pump water heater to use natural CO2 as
refrigerant. Until then, most water heaters were combustion type (gas or petroleum water heaters) orelectric type (electric water heaters), with a few solar-powered water heaters and virtually there were noother types.

・ Eco-Cute is combination of “eco” from economy and ecology and kyuto, the Japanese word for hotwater supply (pronounced like “cute”).
u Natural Refrigerant Heat Pump Water Heater
EcoCute Equipment Overview and Hot Water Supply Mechanism

KitchenCompressor
Electric Energy 1

Hot Water Storage Unit

Air Heat Exchanger

Atmospheric Thermal Energy 2 or more

Heat Pump Unit

Water
Heat
Exchanger

CO2
RefrigerationCycle

1+2 or more
=3 or more

Water
heating

Expansion
Valve

Heat Pump Unit

ObtainedHot Water
SupplyEnergy

Adjustment
Valve
Hot Water
SupplyWashroomBath3 ormorePump
Water Supply

Hot Water Storage Unit

Effects or Remarks

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Primary energy

Incineration equipment

Fossil fuelEfficiency: 90 %44

Reduction infossil fuelconsumption byapprox. 40 %Average power
generation
efficiency ofpower plants
Approx. 37 %170 Generation loss

Quantityof heatWaste heat

Eco Cute

Coefficient ofPerformance = 3.0

Quantityof heat

COP(Coefficient of performance)

Transmission lossu Compared to flash urban gas-powered water heaters, the Eco-Cute reduces primary energy used 40%.
u The natural refrigerant (CO2) used in the Eco-Cute does not destroy the ozone layer. Additionally, since
CO2 generated in industrial and manufacturing processes is used as refrigerant, the Eco-Cute promotes
the recycling of resources.
u Since its launch in 2001, cumulative shipments have exceeded 8 million units.

Installation in Practice or Schedule
Domesticu Natural Refrigerant Heat Pump Water Heaters
Trends in Cumulative EcoCute Shipments[10,000 units]Mar. 2022 Over 8 million

Jun. 2018 Over 6 million

Oct. 2013 Over 4 million

Oct.2009 Over 2 million[FY]

Contact:

Heat Pump and Thermal Storage Technology Center of Japan
International & Technical Research Department
1-28-5 Hulic Kakigaracho Bldg., 6F, Kakigaracho Nihonbashi, Chuo-ku,Tokyo, Japan
Tel: +81-3-5643-2404 Fax: +81-3-5641-4501 URL: http://www.hptcj.or.jp/e/index.html