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69-496: Located near the old city wall, it was designed as a pedestrian-oriented combination of public and private space that encourages the use of shared resources and reduces the need for wasteful modes of transit. Linked Hybrid was built from 2003 to 2009. It has over 2500 inhabitants. It contains 750 apartments, commercial areas, parking, hotel, cinema, and educational facilities including a kindergarten and Montessori school. Linked Hybrid's ground source heat pump system shoulders 70% of

138-503: A cold heat sink to a hot heat sink. Specifically, the heat pump transfers thermal energy using a refrigeration cycle , cooling the cool space and warming the warm space. In cold weather, a heat pump can move heat from the cool outdoors to warm a house (e.g. winter); the pump may also be designed to move heat from the house to the warmer outdoors in warm weather (e.g. summer). As they transfer heat rather than generating heat, they are more energy-efficient than other ways of heating or cooling

207-439: A fan and the other which either directly heats the air inside the building or heats water which is then circulated around the building through radiators or underfloor heating which releases the heat to the building. These devices can also operate in a cooling mode where they extract heat via the internal heat exchanger and eject it into the ambient air using the external heat exchanger. Some can be used to heat water for washing which

276-449: A fixed speed compressor and fixed aperture expansion valve. Applications that need to operate at a high coefficient of performance in very varied conditions, as is the case with heat pumps where external temperatures and internal heat demand vary considerably through the seasons, typically use a variable speed inverter compressor and an adjustable expansion valve to control the pressures of the cycle more accurately. The above discussion

345-413: A flow temperature up to 80 °C (176 °F). As of 2023 about 10% of building heating worldwide is from ASHPs. They are the main way to phase out gas boilers (also known as "furnaces") from houses, to avoid their greenhouse gas emissions . Air-source heat pumps are used to move heat between two heat exchangers, one outside the building which is fitted with fins through which air is forced using

414-490: A fuel in a boiler/furnace or by use of resistive electric heaters . Exhaust air heat pumps extract heat from the exhaust air of a building and require mechanical ventilation . Two classes exist: A solar-assisted heat pump (SAHP) is a machine that combines a heat pump and thermal solar panels and/or PV solar panels in a single integrated system. Typically these two technologies are used separately (or only placing them in parallel) to produce hot water . In this system

483-428: A gas cycle may be less efficient than a vapor compression cycle because the gas cycle works on the reverse Brayton cycle instead of the reverse Rankine cycle . As such, the working fluid never receives or rejects heat at constant temperature. In the gas cycle, the refrigeration effect is equal to the product of the specific heat of the gas and the rise in temperature of the gas in the low temperature side. Therefore, for

552-401: A given amount of fuel, or can improve the temperature (hence the quality) of waste heat from other processes. This second use is the most studied one and has been applied to several industrial applications. The merit of a refrigerator or heat pump is given by a parameter called the coefficient of performance (COP). The equation is: where The detailed COP of a refrigerator is given by

621-529: A heat pump is expressed as a coefficient of performance (COP), or seasonal coefficient of performance (SCOP). The higher the number, the more efficient a heat pump is. For example, an air-to-water heat pump that produces 6kW at a SCOP of 4.62 will give over 4kW of energy into a heating system for every kilowatt of energy that the heat pump uses itself to operate. When used for space heating, heat pumps are typically more energy-efficient than electric resistance and other heaters. Because of their high efficiency and

690-456: A heat pump is greater than one so the work required is less than the heat transferred, making a heat pump a more efficient form of heating than electrical resistance heating. As the temperature of the higher-temperature reservoir increases in response to the heat flowing into it, the coefficient of performance decreases, causing an increasing amount of work to be required for each unit of heat being transferred. The coefficient of performance, and

759-403: A heat pump is typically a vapor-compression refrigeration device that includes a reversing valve and optimized heat exchangers so that the direction of heat flow (thermal energy movement) may be reversed. The reversing valve switches the direction of refrigerant through the cycle and therefore the heat pump may deliver either heating or cooling to a building. Because the two heat exchangers,

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828-405: A high reduction of CO 2 emissions (in some cases more than 50%). Industrial heat pumps can heat up to 200 °C, and can meet the heating demands of many light industries . In Europe alone, 15 GW of heat pumps could be installed in 3,000 facilities in the paper, food and chemicals industries. The performance of a heat pump is determined by the ability of the pump to extract heat from

897-417: A higher pressure, resulting in a higher temperature as well. The hot, compressed vapor is then in the thermodynamic state known as a superheated vapor and it is at a temperature and pressure at which it can be condensed with either cooling water or cooling air flowing across the coil or tubes. In heating mode this heat is used to heat the building using the internal heat exchanger, and in cooling mode this heat

966-413: A home. A gaseous refrigerant is compressed so its pressure and temperature rise. When operating as a heater in cold weather, the warmed gas flows to a heat exchanger in the indoor space where some of its thermal energy is transferred to that indoor space, causing the gas to condense to its liquid state. The liquified refrigerant flows to a heat exchanger in the outdoor space where the pressure falls,

1035-402: A low temperature environment (the source ) and deliver it to a higher temperature environment (the sink ). Performance varies, depending on installation details, temperature differences, site elevation, location on site, pipe runs, flow rates, and maintenance. In general, heat pumps work most efficiently (that is, the heat output produced for a given energy input) when the difference between

1104-427: A low-temperature source, T L , in the amount Q L . Next, the refrigerant is compressed isentropically (adiabatically, without heat transfer) and its temperature rises to that of the high-temperature source, T H . Then at this high temperature, the refrigerant isothermally rejects heat in the amount Q H < 0 (negative according to the sign convention for heat lost by the system). Also during this stage,

1173-410: A lower carbon footprint than gas-fired condensing boilers : however, in 2021 they only met 10%. Heat flows spontaneously from a region of higher temperature to a region of lower temperature. Heat does not flow spontaneously from lower temperature to higher, but it can be made to flow in this direction if work is performed. The work required to transfer a given amount of heat is usually much less than

1242-434: A quantum equivalent, is reversible so the four processes that comprise it, two isothermal and two isentropic, can also be reversed. When a Carnot cycle runs in reverse, it is called a reverse Carnot cycle . A refrigerator or heat pump that acts according to the reversed Carnot cycle is called a Carnot refrigerator or Carnot heat pump, respectively. In the first stage of this cycle, the refrigerant absorbs heat isothermally from

1311-527: A sealed chamber driven by a loudspeaker to achieve a temperature difference across the chamber. Electrocaloric heat pumps are solid state. The International Energy Agency estimated that, as of 2021, heat pumps installed in buildings have a combined capacity of more than 1000 GW. They are used for heating, ventilation, and air conditioning (HVAC) and may also provide domestic hot water and tumble clothes drying. The purchase costs are supported in various countries by consumer rebates. In HVAC applications,

1380-406: A smaller footprint than window mounted air conditioners that just do cooling. In water heating applications, heat pumps may be used to heat or preheat water for swimming pools, homes or industry. Usually heat is extracted from outdoor air and transferred to an indoor water tank. Large (megawatt-scale) heat pumps are used for district heating . However as of 2022 about 90% of district heat

1449-410: A technique called displacement ventilation, in which air that is slightly below desired temperature in a room is released from the floor. The cooler air displaces the warmer air, causing it to be released from the room and resulting in a cooler overall space and a fresh breathing environment. Heat pump A heat pump is a device that consumes energy (usually electricity) to transfer heat from

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1518-400: A whole house and are often also used to provide domestic hot water . An ASHP can typically gain 4 kWh thermal energy from 1 kWh electric energy. They are optimized for flow temperatures between 30 and 40 °C (86 and 104 °F), suitable for buildings with heat emitters sized for low flow temperatures. With losses in efficiency, an ASHP can even provide full central heating with

1587-525: Is a heating/cooling system for buildings that use a type of heat pump to transfer heat to or from the ground, taking advantage of the relative constancy of temperatures of the earth through the seasons. Ground-source heat pumps (GSHPs) – or geothermal heat pumps (GHP), as they are commonly termed in North America – are among the most energy-efficient technologies for providing HVAC and water heating , using far less energy than can be achieved by burning

1656-417: Is also referred to as a hybrid heat pump which is however a broader field. Thanks to this integration, the device can obtain cooling and heating effects using both thermal and electrical energy sources. This type of systems is well coupled with cogeneration systems where both heat and electricity are produced. Depending on the configuration, the system can maximise heating and cooling production from

1725-422: Is based on the ideal vapor-compression refrigeration cycle and does not take into account real-world effects like frictional pressure drop in the system, slight thermodynamic irreversibility during the compression of the refrigerant vapor, or non-ideal gas behavior (if any). In the early years of the twentieth century, the vapor absorption cycle using water-ammonia systems was popular and widely used but, after

1794-455: Is expected to be available before the 2030s or 2040s. Vapor-compression uses a circulating refrigerant as the medium which absorbs heat from one space, compresses it thereby increasing its temperature before releasing it in another space. The system normally has eight main components: a compressor , a reservoir, a reversing valve which selects between heating and cooling mode, two thermal expansion valves (one used when in heating mode and

1863-575: Is from fossil fuels . In Europe, heat pumps account for a mere 1% of heat supply in district heating networks but several countries have targets to decarbonise their networks between 2030 and 2040. Possible sources of heat for such applications are sewage water, ambient water (e.g. sea, lake and river water), industrial waste heat , geothermal energy , flue gas , waste heat from district cooling and heat from solar seasonal thermal energy storage . Large-scale heat pumps for district heating combined with thermal energy storage offer high flexibility for

1932-566: Is produced. An increasing share of low-carbon energy sources such as wind and solar will lower the impact on the climate. In most settings, heat pumps will reduce CO 2 emissions compared to heating systems powered by fossil fuels . In regions accounting for 70% of world energy consumption , the emissions savings of heat pumps compared with a high-efficiency gas boiler are on average above 45% and reach 80% in countries with cleaner electricity mixes. These values can be improved by 10 percentage points, respectively, with alternative refrigerants. In

2001-411: Is rejected via the external heat exchanger. The condensed, liquid refrigerant, in the thermodynamic state known as a saturated liquid , is next routed through an expansion valve where it undergoes an abrupt reduction in pressure. That pressure reduction results in the adiabatic flash evaporation of a part of the liquid refrigerant. The auto-refrigeration effect of the adiabatic flash evaporation lowers

2070-415: Is required to achieve this. An air conditioner requires work to cool a living space, moving heat from the interior being cooled (the heat source) to the outdoors (the heat sink). Similarly, a refrigerator moves heat from inside the cold icebox (the heat source) to the warmer room-temperature air of the kitchen (the heat sink). The operating principle of an ideal heat engine was described mathematically using

2139-399: Is similar to the compression cycle, but depends on the partial pressure of the refrigerant vapor. In the absorption system, the compressor is replaced by an absorber and a generator. The absorber dissolves the refrigerant in a suitable liquid (dilute solution) and therefore the dilute solution becomes a strong solution. In the generator, on heat addition, the temperature increases, and with it,

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2208-399: Is stored in a domestic hot water tank. Air-source heat pumps are relatively easy and inexpensive to install, so are the most widely used type. In mild weather, coefficient of performance (COP) may be between 2 and 5, while at temperatures below around −8 °C (18 °F) an air-source heat pump may still achieve a COP of 1 to 4. A ground source heat pump (also geothermal heat pump)

2277-417: Is typically R32 refrigerant or R290 refrigerant. Then the pressure is increased and the refrigerant leaves as a higher temperature and higher pressure superheated gas. This hot pressurised gas then passes through the condenser where it releases heat to the surroundings as it cools and condenses completely. The cooler high-pressure liquid next passes through the expansion valve (throttle valve) which reduces

2346-574: The Carnot cycle by Sadi Carnot in 1824. An ideal refrigerator or heat pump can be thought of as an ideal heat engine that is operating in a reverse Carnot cycle. Heat pump cycles and refrigeration cycles can be classified as vapor compression , vapor absorption , gas cycle , or Stirling cycle types. The vapor-compression cycle is used by many refrigeration, air conditioning , and other cooling applications and also within heat pump for heating applications. There are two heat exchangers, one being

2415-439: The condenser , which is hotter and releases heat, and the other being the evaporator, which is colder and accepts heat. For applications which need to operate in both heating and cooling modes, a reversing valve is used to switch the roles of these two heat exchangers. At the start of the thermodynamic cycle the refrigerant enters the compressor as a low pressure and low temperature vapor. In heat pumps, this refrigerant

2484-506: The refrigerant enters the evaporator with a lower vapor content. This can be achieved by cooling the liquid refrigerant after condensation. The gaseous refrigerant condenses on the heat exchange surface of the condenser. To achieve a heat flow from the gaseous flow center to the wall of the condenser, the temperature of the liquid refrigerant must be lower than the condensation temperature. Additional subcooling can be achieved by heat exchange between relatively warm liquid refrigerant leaving

2553-416: The working fluid is a gas that is compressed and expanded but does not change phase, the refrigeration cycle is called a gas cycle . Air is most often this working fluid. As there is no condensation and evaporation intended in a gas cycle, components corresponding to the condenser and evaporator in a vapor compression cycle are the hot and cold gas-to-gas heat exchangers . For given extreme temperatures,

2622-563: The Commission Regulation (EU) No. 813/2013. A heat pump's operating performance in cooling mode is characterized in the US by either its energy efficiency ratio (EER) or seasonal energy efficiency ratio (SEER), both of which have units of BTU/(h·W) (note that 1 BTU/(h·W) = 0.293 W/W) and larger values indicate better performance. The carbon footprint of heat pumps depends on their individual efficiency and how electricity

2691-513: The US) or Seasonal Performance Factor (in Europe) are ratings of heating performance. The SPF is Total heat output per annum / Total electricity consumed per annum in other words the average heating COP over the year. Window mounted heat pumps run on standard 120v AC outlets and provide heating, cooling, and humidity control. They are more efficient with lower noise levels, condensation management, and

2760-525: The United States, 70% of houses could reduce emissions by installing a heat pump. The rising share of renewable electricity generation in many countries is set to increase the emissions savings from heat pumps over time. Heating systems powered by green hydrogen are also low-carbon and may become competitors, but are much less efficient due to the energy loss associated with hydrogen conversion, transport and use. In addition, not enough green hydrogen

2829-479: The amount of heat; this is the motivation for using heat pumps in applications such as the heating of water and the interior of buildings. The amount of work required to drive an amount of heat Q from a lower-temperature reservoir such as ambient air to a higher-temperature reservoir such as the interior of a building is: W = Q C O P {\displaystyle W={\frac {Q}{\mathrm {COP} }}} where The coefficient of performance of

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2898-421: The cold refrigerant mixture. At the same time, the circulating air is cooled and thus lowers the temperature of the enclosed space to the desired temperature. The evaporator is where the circulating refrigerant absorbs and removes heat which is subsequently rejected in the condenser and transferred elsewhere by the water or air used in the condenser. To complete the refrigeration cycle , the refrigerant vapor from

2967-469: The complex's yearly heating and cooling load. The system consists of 655 geothermal wells, 100 meters below the basement foundation. The underground wells have taken the place of above-ground space normally needed for cooling towers, increasing available green areas, minimizing noise pollution and significantly reducing the CO 2 emissions created by traditional heating/cooling methods. Linked Hybrid makes use of

3036-404: The conceptual and mathematical models for heat pump , air conditioning and refrigeration systems. A heat pump is a mechanical system that transmits heat from one location (the "source") at a certain temperature to another location (the "sink" or "heat sink") at a higher temperature. Thus a heat pump may be thought of as a "heater" if the objective is to warm the heat sink (as when warming

3105-754: The condenser and evaporator, must swap functions, they are optimized to perform adequately in both modes. Therefore, the Seasonal Energy Efficiency Rating (SEER in the US) or European seasonal energy efficiency ratio of a reversible heat pump is typically slightly less than those of two separately optimized machines. For equipment to receive the US Energy Star rating, it must have a rating of at least 14 SEER. Pumps with ratings of 18 SEER or above are considered highly efficient. The highest efficiency heat pumps manufactured are up to 24 SEER. Heating seasonal performance factor (in

3174-429: The condenser and the cooler refrigerant vapor emerging from the evaporator. The enthalpy difference required for the subcooling leads to the superheating of the vapor drawn into the compressor. When the increase in cooling achieved by subcooling is greater that the compressor drive input required to overcome the additional pressure losses, such a heat exchange improves the coefficient of performance. One disadvantage of

3243-451: The development of the vapor compression cycle, it lost much of its importance because of its low coefficient of performance (about one fifth of that of the vapor compression cycle). Nowadays, the vapor absorption cycle is used only where heat is more readily available than electricity, such as industrial waste heat , solar thermal energy by solar collectors , or off-the-grid refrigeration in recreational vehicles . The absorption cycle

3312-445: The evaporator is again a saturated vapor and is routed back into the compressor. Over time, the evaporator may collect ice or water from ambient humidity . The ice is melted through defrosting cycle. An internal heat exchanger is either used to heat/cool the interior air directly or to heat water that is then circulated through radiators or underfloor heating circuit to either heat or cool the buildings. Heat input can be improved if

3381-545: The following equation: The COP of a heat pump (sometimes referred to as coefficient of amplification COA) is given by the following equations, where the first law of thermodynamics : W n e t , i n + Q L + Q H = Δ c y c l e U = 0 {\displaystyle W_{net,in}+Q_{L}+Q_{H}=\Delta _{cycle}U=0} and | Q H | = − Q H {\displaystyle |Q_{H}|=-Q_{H}}

3450-406: The ground is a constant temperature source, a ground-source heat pump is not subjected to large temperature fluctuations, and therefore is the most energy-efficient type of heat pump. The "seasonal coefficient of performance" (SCOP) is a measure of the aggregate energy efficiency measure over a period of one year which is dependent on regional climate. One framework for this calculation is given by

3519-456: The ground. The body of water does, however, need to be large enough to be able to withstand the cooling effect of the unit without freezing or creating an adverse effect for wildlife. The largest water-source heat pump was installed in the Danish town of Esbjerg in 2023. A thermoacoustic heat pump operates as a thermoacoustic heat engine without refrigerant but instead uses a standing wave in

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3588-618: The heat source and the heat sink is small. When using a heat pump for space or water heating, therefore, the heat pump will be most efficient in mild conditions, and decline in efficiency on very cold days. Performance metrics supplied to consumers attempt to take this variation into account. Common performance metrics are the SEER (in cooling mode) and seasonal coefficient of performance (SCOP) (commonly used just for heating), although SCOP can be used for both modes of operation. Larger values of either metric indicate better performance. When comparing

3657-436: The increasing share of fossil-free sources in electrical grids, heat pumps are playing a key role in climate change mitigation . Consuming 1 kWh of electricity, they can transfer 1 to 4.5 kWh of thermal energy into a building. The carbon footprint of heat pumps depends on how electricity is generated , but they usually reduce emissions. Heat pumps could satisfy over 80% of global space and water heating needs with

3726-405: The inside of a home on a cold day), or a "refrigerator" or “cooler” if the objective is to cool the heat source (as in the normal operation of a freezer). The operating principles in both cases are the same; energy is used to move heat from a colder place to a warmer place. According to the second law of thermodynamics , heat cannot spontaneously flow from a colder location to a hotter area; work

3795-502: The integration of variable renewable energy . Therefore, they are regarded as a key technology for limiting climate change by phasing out fossil fuels . They are also a crucial element of systems which can both heat and cool districts . There is great potential to reduce the energy consumption and related greenhouse gas emissions in industry by application of industrial heat pumps, for example for process heat . Short payback periods of less than 2 years are possible, while achieving

3864-487: The liquid evaporates and the temperature of the gas falls. It is now colder than the temperature of the outdoor space being used as a heat source. It can again take up energy from the heat source, be compressed and repeat the cycle. Air source heat pumps are the most common models, while other types include ground source heat pumps , water source heat pumps and exhaust air heat pumps . Large-scale heat pumps are also used in district heating systems. The efficiency of

3933-655: The long run. Milestones: An air source heat pump (ASHP) is a heat pump that can absorb heat from air outside a building and release it inside; it uses the same vapor-compression refrigeration process and much the same equipment as an air conditioner , but in the opposite direction. ASHPs are the most common type of heat pump and, usually being smaller, tend to be used to heat individual houses or flats rather than blocks, districts or industrial processes. Air-to-air heat pumps provide hot or cold air directly to rooms, but do not usually provide hot water. Air-to-water heat pumps use radiators or underfloor heating to heat

4002-414: The other when used in cooling mode) and two heat exchangers, one associated with the external heat source/sink and the other with the interior. In heating mode the external heat exchanger is the evaporator and the internal one being the condenser; in cooling mode the roles are reversed. Circulating refrigerant enters the compressor in the thermodynamic state known as a saturated vapor and is compressed to

4071-645: The partial pressure of the refrigerant vapor is released from the strong solution. However, the generator requires a heat source, which would consume energy unless waste heat is used. In an absorption refrigerator, a suitable combination of refrigerant and absorbent is used. The most common combinations are ammonia (refrigerant) and water (absorbent), and water (refrigerant) and lithium bromide (absorbent). Absorption refrigeration systems can be powered by combustion of fossil fuels (e.g., coal , oil , natural gas , etc.) or renewable energy (e.g., waste-heat recovery, biomass combustion, or solar energy ). When

4140-444: The performance of heat pumps, the term performance is preferred to efficiency , with coefficient of performance (COP) being used to describe the ratio of useful heat movement per work input. An electrical resistance heater has a COP of 1.0, which is considerably lower than a well-designed heat pump which will typically have a COP of 3 to 5 with an external temperature of 10 °C and an internal temperature of 20 °C. Because

4209-431: The pressure abruptly causing the temperature to drop dramatically. The cold low pressure mixture of liquid and vapor next travels through the evaporator where it vaporizes completely as it accepts heat from the surroundings before returning to the compressor as a low pressure low temperature gas to start the cycle again. Some simpler applications with fixed operating temperatures, such as a domestic refrigerator , may use

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4278-491: The purpose of heating and pressurizing the aircraft cabin . The Stirling cycle heat engine can be driven in reverse, using a mechanical energy input to drive heat transfer in a reversed direction (i.e. a heat pump, or refrigerator). There are several design configurations for such devices that can be built. Several such setups require rotary or sliding seals, which can introduce difficult tradeoffs between frictional losses and refrigerant leakage. The Carnot cycle , which has

4347-452: The refrigerant changes from a saturated vapor to a saturated liquid in the condenser. Lastly, the refrigerant expands isentropically until its temperature falls to that of the low-temperature source, T L . An absorption-compression heat pump (ACHP) is a device that integrate an electric compressor in an absorption heat pump . In some cases this is obtained by combining a vapor-compression heat pump and an absorption heat pump . It

4416-482: The same cooling load, gas refrigeration cycle machines require a larger mass flow rate, which in turn increases their size. Because of their lower efficiency and larger bulk, air cycle coolers are not often applied in terrestrial refrigeration. The air cycle machine is very common, however, on gas turbine -powered jet airliners since compressed air is readily available from the engines' compressor sections. These jet aircraft's cooling and ventilation units also serve

4485-406: The solar thermal panel performs the function of the low temperature heat source and the heat produced is used to feed the heat pump's evaporator. The goal of this system is to get high COP and then produce energy in a more efficient and less expensive way. A water-source heat pump works in a similar manner to a ground-source heat pump, except that it takes heat from a body of water rather than

4554-792: The subcooling of liquids is that the difference between the condensing temperature and the heat-sink temperature must be larger. This leads to a moderately high pressure difference between condensing and evaporating pressure, whereby the compressor energy increases. Pure refrigerants can be divided into organic substances ( hydrocarbons (HCs), chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), and HCFOs), and inorganic substances ( ammonia ( NH 3 ), carbon dioxide ( CO 2 ), and water ( H 2 O ) ). Their boiling points are usually below −25 °C. Heat pump and refrigeration cycle#Coefficient of performance Thermodynamic heat pump cycles or refrigeration cycles are

4623-402: The temperature of the liquid and-vapor refrigerant mixture to where it is colder than the temperature of the enclosed space to be refrigerated. The cold mixture is then routed through the coil or tubes in the evaporator. A fan circulates the warm air in the enclosed space across the coil or tubes carrying the cold refrigerant liquid and vapor mixture. That warm air evaporates the liquid part of

4692-420: The work required by a heat pump can be calculated easily by considering an ideal heat pump operating on the reversed Carnot cycle : This is the theoretical amount of heat pumped but in practice it will be less for various reasons, for example if the outside unit has been installed where there is not enough airflow. More data sharing with owners and academics—perhaps from heat meters —could improve efficiency in

4761-481: Was used in one of the last steps: Both the COP of a refrigerator and a heat pump can be greater than one. Combining these two equations results in: This implies that COP HP will be greater than one because COP R will be a positive quantity. In a worst-case scenario, the heat pump will supply as much energy as it consumes, making it act as a resistance heater. However, in reality, as in home heating, some of Q H

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