Originally posted by Matthew Jones
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There are two types of devices, energy conver-ters and energy transfer devices. The efficiency of a heat (energy) transfering devices is called the coefficient of performance (COP) unlike the energy conversion devices. COP is also the ratio of Energy Output to the Energy Input like the energy efficiency.
In an energy converter, the output will be a portion of the energy input and it may be less than the energy input. Therefore, the efficiency will be less than 100% by the laws of thermodynamics. In an energy transfer device, the energy output is the amount of heat extracted from the heat source (Space to be cooled-in case of refrigeration). The extracted energy is not a portion of the input energy. The extracted energy can exceed the input energy. Therefore, the efficiency of an energy transfering devices can be higher than 100% without violating the first law of thermodynamics. Therefore, the name coefficient of performance.
In an energy converter, the output will be a portion of the energy input and it may be less than the energy input. Therefore, the efficiency will be less than 100% by the laws of thermodynamics. In an energy transfer device, the energy output is the amount of heat extracted from the heat source (Space to be cooled-in case of refrigeration). The extracted energy is not a portion of the input energy. The extracted energy can exceed the input energy. Therefore, the efficiency of an energy transfering devices can be higher than 100% without violating the first law of thermodynamics. Therefore, the name coefficient of performance.
coefficient of performance (COP)
Ratio of work or useful output to the amount of work or energy input, used generally as a measure of the energy-efficiency of air conditioners, space heaters and other cooling and heating devices. COP equals heat delivered (output) in British thermal units (Btu) per hour divided by the heat equivalent of the electric energy input (one watt = 3.413 Btu/hour) or, alternatively, energy efficiency ratio divided by 3.413. Higher the COP, higher the efficiency of the equipment.
Ratio of work or useful output to the amount of work or energy input, used generally as a measure of the energy-efficiency of air conditioners, space heaters and other cooling and heating devices. COP equals heat delivered (output) in British thermal units (Btu) per hour divided by the heat equivalent of the electric energy input (one watt = 3.413 Btu/hour) or, alternatively, energy efficiency ratio divided by 3.413. Higher the COP, higher the efficiency of the equipment.
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