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Pentafluoroethane is a common replacement for various chlorofluorocarbons (i.e Freon) in new refrigerant systems, especially for air-conditioning. The zeotropic mix of difluoromethane with pentafluoroethane ( R-125 ) and tetrafluoroethane ( R-134a ) is known as R-407A through R-407F depending on the composition.
The first of the cooling load factors used in this method is the CLTD, or the Cooling Load Temperature Difference. This factor is used to represent the temperature difference between indoor and outdoor air with the inclusion of the heating effects of solar radiation. [1] [5] The second factor is the CLF, or the cooling load factor.
R-12 was used in most refrigeration and vehicle air conditioning applications prior to 1994 before being replaced by 1,1,1,2-tetrafluoroethane (R-134a), which has an insignificant ozone depletion potential. Automobile manufacturers began phasing in R-134a around 1993 [citation needed].
Cooling capacity is the measure of a cooling system's ability to remove heat. [1] It is equivalent to the heat supplied to the evaporator/boiler part of the refrigeration cycle and may be called the "rate of refrigeration" or "refrigeration capacity".
Currently used in residential and commercial air-conditioners and heat pumps. R-134a HFC-134a CH 2 FCF 3: 1,1,1,2-Tetrafluoroethane: 3790 1550 Widely used Most used in 2020 for hydronic heat pumps in Europe and the United States in spite of high GWP. [58] Commonly used in automotive air conditioners prior to phase out which began in 2012. R-410A
Sigma heat, denoted , is a measure of the specific energy of humid air. It is used in the field of mining engineering for calculations relating to the temperature regulation of mine air. Sigma heat is sometimes called total heat , [ 1 ] although total heat may instead mean enthalpy .
In the empirical sciences, the so-called three-sigma rule of thumb (or 3 σ rule) expresses a conventional heuristic that nearly all values are taken to lie within three standard deviations of the mean, and thus it is empirically useful to treat 99.7% probability as near certainty.
Sol-air temperature (T sol-air) is a variable used to calculate cooling load of a building and determine the total heat gain through exterior surfaces. It is an ...