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Mitigating urban heat island effect. [5] [10] [43] [44] Reducing greenhouse gas emissions by replacing fossil fuel energy use devoted to cooling. [11] [5] Reducing local and global temperature increases associated with global warming. [1] [38] Reducing thermal pollution of water resources. [5] Reducing water consumption for wet cooling ...
The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work (energy) required. [ 1 ] [ 2 ] Higher COPs equate to higher efficiency, lower energy (power) consumption and thus lower operating costs.
Infrared radiation can pass through dry, clear air in the wavelength range of 8–13 μm. Materials that can absorb energy and radiate it in those wavelengths exhibit a strong cooling effect. Materials that can also reflect 95% or more of sunlight in the 200 nanometres to 2.5 μm range can exhibit cooling even in direct sunlight. [9]
Radiant systems using low temperature heating and high temperature cooling are typical example of low-exergy systems. Energy sources such as geothermal (direct cooling / geothermal heat pump heating) and solar hot water are compatible with radiant systems. These sources can lead to important savings in terms of primary energy use for buildings.
Energy experts estimate that nearly a fifth of homes, some 4.8 million, are suitable for a heat pump today while another 30%, or 8.4 million, need minimal changes such as loft and cavity wall ...
For a heat engine, thermal efficiency is the ratio of the net work output to the heat input; in the case of a heat pump, thermal efficiency (known as the coefficient of performance or COP) is the ratio of net heat output (for heating), or the net heat removed (for cooling) to the energy input (external work). The efficiency of a heat engine is ...
However, other effectiveness measures that can exceed 1.0 are used for refrigerators, heat pumps and other devices that move heat rather than convert it. It is not called efficiency, but the coefficient of performance, or COP. It is a ratio of useful heating or cooling provided relative to the work (energy) required.
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