I really, really love refrigeration. I will go so far as to say that it’s the most important invention of the modern era. More than internal combustion, nuclear bombs and power, or electrification, refrigeration defines the US. If you’re like most Americans, you preside over at least THREE refrigeration units – one in the house, one in the kitchen, one in the car. The Central Valley in CA, DC, Las Vegas, Phoenix, Dallas, Houston, Atlanta – a huge swath of the country would look very different without AC. Not to mention your grocery store.
Awhile back, we began getting concerned about the ozone layer. Out with R-12, in with R-134a. The C-Cl bond in R-12, see, was labile enough to break apart in the upper atmosphere and destroy ozone. R-134a didn’t have a C-Cl bond, only hale and hearty C-H and C-F bonds. If you take a look at the earlier link, you can read where some old AC jocks claim that R-134a was just a political pet and a pretty crappy refrigerant.
Interestingly, one iodinated refrigerant has been suggested. Apparently, it’s sufficiently reactive it doesn’t even make it into the upper atmosphere. No idea how far it’s made it. I really, really love refrigeration. Whenever I move into a new place I inspect the fridge and central air to see if it’s still an R-12/R-22 unit or if it’s made it over to R-134a.