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AC refrigerant in cars,greenhouse effect reasoning

  1. Feb 26, 2014 #1
    I'm a mechanical engineer and am learning about the different refrigerants used.
    2 of them seem to be the most popular- R134a(C2H2F4) and R1234yf(C3H2F4).

    Why is it that R134a is rated at a Greenhouse effect(GWP) of 1430 where R1234yf is rated at a GWP of 4?

    Both refrigerants produce CO2,I assume.Won't R1234yf produce more of it considering it has more carbon atoms?
  2. jcsd
  3. Feb 26, 2014 #2
    It seems you are misunderstanding the concept of a GWP. I wasn't aware of how this rating is measured/calculated but a quick Google/Wikipedia excursion revealed that GWP is not related to the production of CO2 by a given compound, but is a measure of how much EM energy a given compound will absorb in a certain amount of time relative to the same mass of CO2. The CO2 appears to be arbitrarily set to 1 as a reference.

    See the Wikipedia for more information: http://en.wikipedia.org/wiki/Global-warming_potential
    Last edited: Feb 26, 2014
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