EcoCute
Encyclopedia
The EcoCute is an energy efficient
electric heat pump
, water heating
and supply system that uses heat extracted from the air to heat water
for domestic, industrial and commercial
use. Instead of the more conventional ammonia
or haloalkane
gas
es, EcoCute uses supercritical
carbon dioxide
as a refrigerant
. The technology offers a means of energy conservation
and reduces the emission of greenhouse gas
.
or Economical
and Cute is a near homonym to ; literally “supply hot water.”
in 1824. Jacob Perkins
invented an ice
-making machine that used ether
in 1843, and Edmond Carré built a refrigerator
that used water
and sulfuric acid
in 1850. In Japan, Fusanosuke Kuhara
, founder of Hitachi, Ltd.
, made an air conditioner for his own home use using compressed CO2
as a refrigerant.
In 1930 Thomas Midgley, Jr.
discovered dichlorodifluoromethane, a chlorinated fluorocarbon (CFC) known as Freon. CFCs rapidly replaced traditional refrigerant substances, including CO2 (which proved hard to compress for domestic use), for use in heat pumps and refrigerators. But from the 1980s CFCs began to lose favor as refrigerant when their damaging effects on the ozone layer
were discovered. An alternative type of refrigerant, Hydro fluoro compounds (HFC), also lost favour when they were identified as greenhouse gases. The Vienna Convention for the Protection of the Ozone Layer
, the Montreal Protocol
and the Kyoto Protocol
call for the complete abandonment of such refrigerants by 2030.
In 1989, amid international concern about the effects of chlorofluorocarbons (CFC and HFC)
on the ozone layer
, scientist Gustav Lorentzen
and SINTEF
patented a method for using CO2 as a refrigerant in heating and cooling. Further research into CO2 refrigeration was then conducted at Shecco (Sustainable Heating and Cooling with CO2) in Brussels
, Belgium
, leading to increasing use of CO2 refrigerant technology in Europe.
In 1993 the Japanese company Denso
, in collaboration with Gustav Lorentzen
, developed an automobile
air conditioner using CO2 as a refrigerant. They demonstrated the invention at the June 1998 International Institute of Refrigeration/Gustav Lorentzen
Conference.Technology of Car air conditioner blooms as EcoCute, Denso
After the conference Denso were approached by CRIEPI (Central Research Institute of Electric Power Industry
) and TEPCO (The Tokyo Electric Power Company
) to develop a prototype air conditioner using natural refrigerant materials instead of Freon. Together they produced 30 prototype
EcoCute units for a year-long experimental installation at locations throughout Japan
, from the cold climate of Hokkaidō
to hotter Okinawa
. After this successful feasibility study
, Denso obtained a patent to compress CO2 refrigerant
for use in a heat pump from SINTEF
in September 2000.
The first commercial domestic EcoCute was marketed in Japan by CORONA Corp. in May 2001, and several manufacturers sold 1.5 million units there by October, 2008.
FEPC
reported 2 million units of EcoCute had been delivered by end of October 2009, and its equivalents CO2 absorption is 9400 km² of forest
.
heating accounting for another 26.9% and cooling by air conditioner another 2.3%. Most of the remaining 37% was spent on electrical home appliances, a field where 21st century innovations in energy conservation began to make considerable energy savings. This left hot water supply as the most difficult area for energy conservation, leaving a gap in the market for the EcoCute. By January 2005, 26 Japanese companies were producing more than 450 models of EcoCute machines, and sales of domestic units increased 130-150% each year between 2001 and 2005.
Denso first introduced the EcoCute outside Japan at the COP9 Milan
, Italy
on December 9, 2003. From 2007, Denso began concentrating on marketing the EcoCute in the EU. In Japan, the Japanese government incorporated the EcoCute into its CO2 reduction program under the Kyoto Protocol
, mandating the installation of 5.2 million units in commercial and domestic properties by 2010. The cost of EcoCute is approximately 500 thousand Japanese yen
as of February - March 2009.
and hot water
storage unit. The components are serially concatenated with sealing
refrigerant CO2 gas in circulation.
The EcoCute derives two units of energy from ambient air temperature for every unit of electrical power it requires. Each of these one unit plus two cost free units produces more than three units of hot water energy, resulting in reduced CO2 emissions compared to water heating via electricity or town gas. To produce 90℃ hot water, an EcoCute consumes 66% less energy than an electric water heater, and costs 80% less than heating water via town gas in Japan. Also, by reducing use of fossil fuels, the EcoCute results in more than 50% reductions in CO2 emissions
The EcoCute's COP is 3.8 in industrial use, while electric power water heating
is 1.0, and gas boiler
is 0.88 including pilot light
loss.
(No. 4575216 - Japan) of Kansai Electric Power Company
, but the term is also used generically to refer to water heaters designed for energy conservation
or greenhouse gas
emission reduction.
Efficient energy use
Efficient energy use, sometimes simply called energy efficiency, is the goal of efforts to reduce the amount of energy required to provide products and services. For example, insulating a home allows a building to use less heating and cooling energy to achieve and maintain a comfortable temperature...
electric heat pump
Heat pump
A heat pump is a machine or device that effectively "moves" thermal energy from one location called the "source," which is at a lower temperature, to another location called the "sink" or "heat sink", which is at a higher temperature. An air conditioner is a particular type of heat pump, but the...
, water heating
Water heating
Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating...
and supply system that uses heat extracted from the air to heat water
Water heating
Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating...
for domestic, industrial and commercial
Commerce
While business refers to the value-creating activities of an organization for profit, commerce means the whole system of an economy that constitutes an environment for business. The system includes legal, economic, political, social, cultural, and technological systems that are in operation in any...
use. Instead of the more conventional ammonia
Ammonia
Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
or haloalkane
Haloalkane
The haloalkanes are a group of chemical compounds derived from alkanes containing one or more halogens. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalkanes are widely used commercially and, consequently, are known under many chemical and...
gas
Gas
Gas is one of the three classical states of matter . Near absolute zero, a substance exists as a solid. As heat is added to this substance it melts into a liquid at its melting point , boils into a gas at its boiling point, and if heated high enough would enter a plasma state in which the electrons...
es, EcoCute uses supercritical
Supercritical fluid
A supercritical fluid is any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist. It can effuse through solids like a gas, and dissolve materials like a liquid...
carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
as a refrigerant
Refrigerant
A refrigerant is a substance used in a heat cycle usually including, for enhanced efficiency, a reversible phase change from a liquid to a gas. Traditionally, fluorocarbons, especially chlorofluorocarbons, were used as refrigerants, but they are being phased out because of their ozone depletion...
. The technology offers a means of energy conservation
Energy conservation
Energy conservation refers to efforts made to reduce energy consumption. Energy conservation can be achieved through increased efficient energy use, in conjunction with decreased energy consumption and/or reduced consumption from conventional energy sources...
and reduces the emission of greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
.
Etymology
The name of the EcoCute comes from the Japanese phrase , which literally means "natural refrigerant heat pump water heater". Eco is a contraction of either EcologyEcology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...
or Economical
Economic system
An economic system is the combination of the various agencies, entities that provide the economic structure that defines the social community. These agencies are joined by lines of trade and exchange along which goods, money etc. are continuously flowing. An example of such a system for a closed...
and Cute is a near homonym to ; literally “supply hot water.”
History
Modern chemical refrigeration techniques developed after the proposal of the Carnot cycleCarnot cycle
The Carnot cycle is a theoretical thermodynamic cycle proposed by Nicolas Léonard Sadi Carnot in 1824 and expanded by Benoit Paul Émile Clapeyron in the 1830s and 40s. It can be shown that it is the most efficient cycle for converting a given amount of thermal energy into work, or conversely,...
in 1824. Jacob Perkins
Jacob Perkins
Jacob Perkins was an Anglo-American inventor, mechanical engineer and physicist. Born in Newburyport, Massachusetts, Perkins was apprenticed to a goldsmith...
invented an ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
-making machine that used ether
Ether
Ethers are a class of organic compounds that contain an ether group — an oxygen atom connected to two alkyl or aryl groups — of general formula R–O–R'. A typical example is the solvent and anesthetic diethyl ether, commonly referred to simply as "ether"...
in 1843, and Edmond Carré built a refrigerator
Refrigerator
A refrigerator is a common household appliance that consists of a thermally insulated compartment and a heat pump that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room...
that used water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
and sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
in 1850. In Japan, Fusanosuke Kuhara
Fusanosuke Kuhara
was a businessman and politician of Japan.He was a syndicalist, zaibatsu member, and mining industrialist, later becoming a right-wing supporter in wartime Japan....
, founder of Hitachi, Ltd.
Hitachi, Ltd.
is a Japanese multinational conglomerate headquartered in Marunouchi 1-chome, Chiyoda, Tokyo, Japan. The company is the parent of the Hitachi Group as part of the larger DKB Group companies...
, made an air conditioner for his own home use using compressed CO2
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
as a refrigerant.
In 1930 Thomas Midgley, Jr.
Thomas Midgley, Jr.
Thomas Midgley, Jr. was an American mechanical engineer and chemist. Midgley was a key figure in a team of chemists, led by Charles F. Kettering, that developed the tetraethyllead additive to gasoline as well as some of the first chlorofluorocarbons . Over the course of his career, Midgley was...
discovered dichlorodifluoromethane, a chlorinated fluorocarbon (CFC) known as Freon. CFCs rapidly replaced traditional refrigerant substances, including CO2 (which proved hard to compress for domestic use), for use in heat pumps and refrigerators. But from the 1980s CFCs began to lose favor as refrigerant when their damaging effects on the ozone layer
Ozone layer
The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...
were discovered. An alternative type of refrigerant, Hydro fluoro compounds (HFC), also lost favour when they were identified as greenhouse gases. The Vienna Convention for the Protection of the Ozone Layer
Vienna Convention for the Protection of the Ozone Layer
The Vienna Convention for the Protection of the Ozone Layer is a Multilateral Environmental Agreement. It was agreed upon at the Vienna Conference of 1985 and entered into force in 1988....
, the Montreal Protocol
Montreal Protocol
The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion...
and the Kyoto Protocol
Kyoto Protocol
The Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change , aimed at fighting global warming...
call for the complete abandonment of such refrigerants by 2030.
In 1989, amid international concern about the effects of chlorofluorocarbons (CFC and HFC)
Haloalkane
The haloalkanes are a group of chemical compounds derived from alkanes containing one or more halogens. They are a subset of the general class of halocarbons, although the distinction is not often made. Haloalkanes are widely used commercially and, consequently, are known under many chemical and...
on the ozone layer
Ozone layer
The ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...
, scientist Gustav Lorentzen
Gustav Lorentzen (scientist)
Gustav Fredrik Lorentzen was a thermodynamic scientist from Norway.Gustav Lorentzen was a professor at Norwegian Institute of Technology, and Norwegian University of Science and Technology. In the late 1980s, Gustav Lorentzen rediscovered how CO2 could be used as a refrigerant in heating and...
and SINTEF
SINTEF
SINTEF , headquartered in Trondheim, Norway, is the largest independent research organisation in Scandinavia. Every year, SINTEF supports research and development at 2,000 or so Norwegian and overseas companies via its research and development activity....
patented a method for using CO2 as a refrigerant in heating and cooling. Further research into CO2 refrigeration was then conducted at Shecco (Sustainable Heating and Cooling with CO2) in Brussels
Brussels
Brussels , officially the Brussels Region or Brussels-Capital Region , is the capital of Belgium and the de facto capital of the European Union...
, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, leading to increasing use of CO2 refrigerant technology in Europe.
In 1993 the Japanese company Denso
DENSO
is a global automotive components manufacturer headquartered in the city of Kariya, Aichi Prefecture, Japan. Established December 16, 1949 as , in 1996 the company became DENSO Corporation worldwide...
, in collaboration with Gustav Lorentzen
Gustav Lorentzen (scientist)
Gustav Fredrik Lorentzen was a thermodynamic scientist from Norway.Gustav Lorentzen was a professor at Norwegian Institute of Technology, and Norwegian University of Science and Technology. In the late 1980s, Gustav Lorentzen rediscovered how CO2 could be used as a refrigerant in heating and...
, developed an automobile
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
air conditioner using CO2 as a refrigerant. They demonstrated the invention at the June 1998 International Institute of Refrigeration/Gustav Lorentzen
Gustav Lorentzen (scientist)
Gustav Fredrik Lorentzen was a thermodynamic scientist from Norway.Gustav Lorentzen was a professor at Norwegian Institute of Technology, and Norwegian University of Science and Technology. In the late 1980s, Gustav Lorentzen rediscovered how CO2 could be used as a refrigerant in heating and...
Conference.Technology of Car air conditioner blooms as EcoCute, Denso
DENSO
is a global automotive components manufacturer headquartered in the city of Kariya, Aichi Prefecture, Japan. Established December 16, 1949 as , in 1996 the company became DENSO Corporation worldwide...
After the conference Denso were approached by CRIEPI (Central Research Institute of Electric Power Industry
Central Research Institute of Electric Power Industry
The Central Research Institute of Electric Power Industry is a Japanese non-profit foundation that conducts research and development of technologies in a variety of scientific and technical fields related to the electric power industry. Also, CRIEPI researches many aspects of social matters...
) and TEPCO (The Tokyo Electric Power Company
The Tokyo Electric Power Company
, also known as or TEPCO, is an electric utility servicing Japan's Kantō region, Yamanashi Prefecture, and the eastern portion of Shizuoka Prefecture. This area includes Tokyo...
) to develop a prototype air conditioner using natural refrigerant materials instead of Freon. Together they produced 30 prototype
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...
EcoCute units for a year-long experimental installation at locations throughout Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, from the cold climate of Hokkaidō
Hokkaido
, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...
to hotter Okinawa
Okinawa Prefecture
is one of Japan's southern prefectures. It consists of hundreds of the Ryukyu Islands in a chain over long, which extends southwest from Kyūshū to Taiwan. Okinawa's capital, Naha, is located in the southern part of Okinawa Island...
. After this successful feasibility study
Feasibility study
Feasibility studies aim to objectively and rationally uncover the strengths and weaknesses of the existing business or proposed venture, opportunities and threats as presented by the environment, the resources required to carry through, and ultimately the prospects for success. In its simplest...
, Denso obtained a patent to compress CO2 refrigerant
Refrigerant
A refrigerant is a substance used in a heat cycle usually including, for enhanced efficiency, a reversible phase change from a liquid to a gas. Traditionally, fluorocarbons, especially chlorofluorocarbons, were used as refrigerants, but they are being phased out because of their ozone depletion...
for use in a heat pump from SINTEF
SINTEF
SINTEF , headquartered in Trondheim, Norway, is the largest independent research organisation in Scandinavia. Every year, SINTEF supports research and development at 2,000 or so Norwegian and overseas companies via its research and development activity....
in September 2000.
The first commercial domestic EcoCute was marketed in Japan by CORONA Corp. in May 2001, and several manufacturers sold 1.5 million units there by October, 2008.
FEPC
Federation of Electric Power Companies
The , or FEPC for short, is an industry organization of electric utilities in Japan. Its objective is to harmonize the plans for electric development in Japan...
reported 2 million units of EcoCute had been delivered by end of October 2009, and its equivalents CO2 absorption is 9400 km² of forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
.
Features and demand
In Japan in 1998, water heating accounted for 33.8% of typical domestic energy consumption, with air conditioner and kerosene heaterKerosene heater
A kerosene heater, also known as a paraffin heater, is a portable, unvented, kerosene-fueled, space-heating device. In the United States they are used mainly for supplemental heat or as a source of emergency heat during a power outage. In some countries, particularly in Japan, they are used as...
heating accounting for another 26.9% and cooling by air conditioner another 2.3%. Most of the remaining 37% was spent on electrical home appliances, a field where 21st century innovations in energy conservation began to make considerable energy savings. This left hot water supply as the most difficult area for energy conservation, leaving a gap in the market for the EcoCute. By January 2005, 26 Japanese companies were producing more than 450 models of EcoCute machines, and sales of domestic units increased 130-150% each year between 2001 and 2005.
Denso first introduced the EcoCute outside Japan at the COP9 Milan
Milan
Milan is the second-largest city in Italy and the capital city of the region of Lombardy and of the province of Milan. The city proper has a population of about 1.3 million, while its urban area, roughly coinciding with its administrative province and the bordering Province of Monza and Brianza ,...
, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
on December 9, 2003. From 2007, Denso began concentrating on marketing the EcoCute in the EU. In Japan, the Japanese government incorporated the EcoCute into its CO2 reduction program under the Kyoto Protocol
Kyoto Protocol
The Kyoto Protocol is a protocol to the United Nations Framework Convention on Climate Change , aimed at fighting global warming...
, mandating the installation of 5.2 million units in commercial and domestic properties by 2010. The cost of EcoCute is approximately 500 thousand Japanese yen
Japanese yen
The is the official currency of Japan. It is the third most traded currency in the foreign exchange market after the United States dollar and the euro. It is also widely used as a reserve currency after the U.S. dollar, the euro and the pound sterling...
as of February - March 2009.
EcoCute machine basics
An EcoCute machine or system consists of a heat pumpHeat pump
A heat pump is a machine or device that effectively "moves" thermal energy from one location called the "source," which is at a lower temperature, to another location called the "sink" or "heat sink", which is at a higher temperature. An air conditioner is a particular type of heat pump, but the...
and hot water
Hot Water
Hot Water is a novel by P.G. Wodehouse, first published on August 17, 1932, in the United Kingdom by Herbert Jenkins, London, and in the United States by Doubleday, Doran, New York. The novel had been serialised in Collier's from 21 May to 6 August 1932...
storage unit. The components are serially concatenated with sealing
Seal (mechanical)
A mechanical seal is a device which helps join systems or mechanisms together by preventing leakage , containing pressure, or excluding contamination...
refrigerant CO2 gas in circulation.
- At the first stage, a heat exchangerHeat exchangerA heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact...
collects heat from the air outside to use as energy for the refrigerant. Air flow is usually obtained using a centrifugal fanCentrifugal fanA centrifugal fan is a mechanical device for moving air or other gases. It has a fan wheel composed of a number of fan blades, or ribs, mounted around a hub. As shown in Figure 1, the hub turns on a driveshaft that passes through the fan housing...
; in cold areas with ambient temperatures around -20 to -25 ℃ an auxiliary fan heaterFan heaterthumb|Typical fan heater's internal partsthumb|Overheat cutoutsA fan heater is a heater that works by using a fan to pass air over a heating element. This heats up the air, which then leaves the heater, warming up the surrounding room...
is attached. - A gas compressorGas compressorA gas compressor is a mechanical device that increases the pressure of a gas by reducing its volume.Compressors are similar to pumps: both increase the pressure on a fluid and both can transport the fluid through a pipe. As gases are compressible, the compressor also reduces the volume of a gas...
is used to heat the gas CO2 refrigerant to around 100℃ under pressure of 10MPaPascal (unit)The pascal is the SI derived unit of pressure, internal pressure, stress, Young's modulus and tensile strength, named after the French mathematician, physicist, inventor, writer, and philosopher Blaise Pascal. It is a measure of force per unit area, defined as one newton per square metre...
via adiabaticAdiabatic processIn thermodynamics, an adiabatic process or an isocaloric process is a thermodynamic process in which the net heat transfer to or from the working fluid is zero. Such a process can occur if the container of the system has thermally-insulated walls or the process happens in an extremely short time,...
compression. The carbon dioxide becomes a supercritical fluidSupercritical fluidA supercritical fluid is any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist. It can effuse through solids like a gas, and dissolve materials like a liquid...
. Several types of compressor can be used, including dual layer cylindrical compressors, scroll compressorScroll compressorA scroll compressor is a device for compressing air or refrigerant...
s, and dual stage rotary compressors - At the second stage a heat exchangerHeat exchangerA heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact...
transfers energy from the hot refrigerant into water to produce hot waterHot WaterHot Water is a novel by P.G. Wodehouse, first published on August 17, 1932, in the United Kingdom by Herbert Jenkins, London, and in the United States by Doubleday, Doran, New York. The novel had been serialised in Collier's from 21 May to 6 August 1932...
. Water temperatures around 5℃ and up are suitable at this stage. - Finally, ejector or expansion valves reduce pressure on the refrigerant, letting it cool via adiabatic expansion and revert to CO2 gas.
The EcoCute derives two units of energy from ambient air temperature for every unit of electrical power it requires. Each of these one unit plus two cost free units produces more than three units of hot water energy, resulting in reduced CO2 emissions compared to water heating via electricity or town gas. To produce 90℃ hot water, an EcoCute consumes 66% less energy than an electric water heater, and costs 80% less than heating water via town gas in Japan. Also, by reducing use of fossil fuels, the EcoCute results in more than 50% reductions in CO2 emissions
The EcoCute's COP is 3.8 in industrial use, while electric power water heating
Water heating
Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating...
is 1.0, and gas boiler
Boiler
A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.-Materials:...
is 0.88 including pilot light
Pilot light
thumb|right|Merker gas fired water heater from the 1930's, with pilot light clearly visible through the aperture in the front cover. The large opening allowed for the manual lighting of the pilot light by a lit match or taper...
loss.
Others
is a registered trademarkTrademark
A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...
(No. 4575216 - Japan) of Kansai Electric Power Company
Kansai Electric Power Company
, also known as , is an electric utility with its operational area of Kansai region, Japan . The company is regarded as one of the leading companies in Kansai, as well as a leader of the Japanese electric power industry....
, but the term is also used generically to refer to water heaters designed for energy conservation
Energy conservation
Energy conservation refers to efforts made to reduce energy consumption. Energy conservation can be achieved through increased efficient energy use, in conjunction with decreased energy consumption and/or reduced consumption from conventional energy sources...
or greenhouse gas
Greenhouse gas
A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in the Earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone...
emission reduction.
See also
- Transcritical cycleTranscritical cycleA transcritical cycle is a thermodynamic cycle where the working fluid goes through both subcritical and supercritical states. This is often the case when carbon dioxide, CO2, is the refrigerant....
- Supercritical fluidSupercritical fluidA supercritical fluid is any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist. It can effuse through solids like a gas, and dissolve materials like a liquid...
- Gustav Lorentzen (scientist)Gustav Lorentzen (scientist)Gustav Fredrik Lorentzen was a thermodynamic scientist from Norway.Gustav Lorentzen was a professor at Norwegian Institute of Technology, and Norwegian University of Science and Technology. In the late 1980s, Gustav Lorentzen rediscovered how CO2 could be used as a refrigerant in heating and...
- R-744
- Heat exchangerHeat exchangerA heat exchanger is a piece of equipment built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact...
- The Cool WarThe Cool WarThe Cool War refers to the debate about the next-generation refrigerant in car air conditioning worldwide, with an ongoing dispute between the Alliance for CO2 Solutions supporting the uptake of sustainable carbon dioxide as a refrigerant in passenger cars, and chemical giants developing new...
External links
- Mayekawa Global ECO CUTE
- Japan warms to Hitachi's Eco Cute TechnologyAction on CO2penhagenCopenhagenCopenhagen is the capital and largest city of Denmark, with an urban population of 1,199,224 and a metropolitan population of 1,930,260 . With the completion of the transnational Øresund Bridge in 2000, Copenhagen has become the centre of the increasingly integrating Øresund Region...
(The UK Government's ambition for a global deal on climate change, Department of Energy and Climate Change) - High-efficient EcoCute models launched, R744.com - 2008-02-01
- Research on Performance Evaluation of Heat Pump Water Heaters, EcoCute 24/31 page;Prize List:(4), Mar.2002, EPAUnited States Environmental Protection AgencyThe U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
Climate Protection Award & 25/31 page Ecocute history, CRIEPI - TEPCO'S 'Eco Cute' the World's First Heat Pump Water Heater for Residential Use
- Technology and Market Development of Heat Pump Water Heaters in Japan, IEAInternational Energy AgencyThe International Energy Agency is a Paris-based autonomous intergovernmental organization established in the framework of the Organisation for Economic Co-operation and Development in 1974 in the wake of the 1973 oil crisis...
, Heat Pump Centre (HPC) - Demand-side management, e8.com.org Car Air Conditioner | publisher = The Auto Channel | date = 2002-12-04 | accessdate = 2008-07-19}}