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| The home mechanic, looking at a can or two of R12 or R134a, may think that government concern over refrigerant is overblown. However, CFCs like R12 have been found high in the atmosphere, where they destroy ozone (since CFCs have been regulated, the ever-widening holes in the ozone layer have been healing themselves). In addition, R134a is 1,400 times as effective at trapping heat as carbon dioxide; a few leaks from a few cars would probably not have any serious impact, but there are an estimated (by the auto industry) 400 million mobile air conditioners out there.
Europe is phasing out R134a due to its relationship to global warming. Carbon dioxide, the current E.U. favorite to replace R134a, is the least powerful greenhouse-gas, but requires high pressures, and is less effective. However, in the United States, the approved replacement is HFO-1234yf. This new refrigerant is dramatically less likely to affect climate change than R134a, and while it will not be required until the 2017 model year, automakers can get greenhouse gas credits from the 2012 to 2016 model years by using it. The new gas was created by Honeywell and DuPont.
R134a, which replaced R12, lives for around 13 years in the atmosphere before breaking down; its “global warming potential” (GWP) is 1,400. 1234yf, on the other hand, breaks up in around 11 days, for a GWP of 4. It was developed to meet European Union directives, which demand a refrigerant with a GWP of less than 150.
Whether HFO-1234yf can be used as a replacement for R-134a is still unclear, but it seems unlikely, as R134a will not be banned; instead, it will have a hefty tax which will prevent frivolous use (e.g. putting in three or four cans a month) and tip the balance for many customers from “frequent refills” to “repair.”
Many have complained about the corrosive effects of R134a and its tendency to leak out of automotive air conditioners much faster than the old R12, which was phased out in the mid-1990s. R1234yf was endorsed by the Society of Automotive Engineers and Japan Automobile Manufacturers Association; a Delphi executive wrote that it was “both a cost-efficient and effective refrigerant option.” It can be used with low-pressure air conditioning systems.
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R134A phase out
