Why Automakers Switched From R12 Freon To R134a (And Now R1234yf)

The very first air conditioning system available from the automotive factory was found in the 1940 Packard and was called the "weather conditioner," among other names. It utilized R12 and, while revolutionary, was expensive, didn't permit fresh air, just recirculation, and reportedly broke down frequently. The system utilized a compressor, a condenser, an evaporator coil, and a blower. Interestingly, the air would blow out from behind the seats, as a few of the major components like the blower were located there. However, this design did mean some trunk space was sacrificed, and the back of your neck would typically receive the most attention from the cold air.

Nevertheless, it ignited the imagination of engineers who would eventually make automotive air conditioning not only more affordable, but far more advanced than earlier versions. Unfortunately, for those in the delivery business, it wouldn't be until 2023 that agreements were tentatively made surrounding UPS drivers finally getting air conditioning in their trucks.

Among the features of the Packard's AC system that stuck around was the use of R12. It was the first widespread refrigerant used across the automotive industry. However, R12 was eventually replaced with R134a, due to environmental concerns. While R134a was the go-to option for many years, it too was eventually found to pose an environmental threat and was replaced with R1234yf, which is used today.

Research in the 1970's by professors F. Sherwood Rowland and Mario J. Molina found that R12, a chlorofluorocarbon (CFC), had the potential for devasting environmental effects. Essentially, CFCs (found in air conditioners and aerosol cans at the time) experience chemical decomposition when exposed to ultraviolet rays near the stratosphere (one of the planet's lowest layers of atmosphere). Essentially, chlorine atoms from CFC would separate, interacting with ozone molecules and destroying them in sizeable quantities. This, along with further studies, eventually led to R12 being phased out in the 1990s.

Then, R134a stepped up as a replacement to R12, because, unlike R12, R134a is a hydrofluorocarbon (HFC). HFCs weren't found to have the same destructive effect on ozone, which solved that issue. However, compared to the cooling power of R12, many felt that R134a was a weak substitute. However, "A Comparison Study of the Thermal Performance of R12 and R134a," published on the Purdue University e-Pubs, found that R134a actually had a greater capacity to cool than R12 in most of the 88 independent tests. The negativity around the change was largely due to poor conversions and the use of cheap parts when switching to R134a in a system built for R12. Even today, you might find climate control performance lacking in some situations, but it can help to incorporate these cool tips to keep your AC blowing cold.

While R134a was found to be much better for the ozone when compared to the previous R12, it too was eventually replaced due to negative environmental impacts. HFCs were found to contribute to warming affects, so a new refrigerant was needed. The EPA mandated new vehicles beginning in 2021 would need to use a substitute for R134a, which had been the go-to refrigerant for decades. While (at least for now), R1234yf, which is a hydrofluoroolefin (HFO), hasn't been shown to produce any significant danger to the environment, it does come with some downsides.

First, unlike its predecessors, R1234yf is considered somewhat flammable. However, extensive testing hasn't shown any hazardous results in terms of its use in automobiles. Unfortunately, though, while safe, R1234yf is also expensive. For example, when comparing price, an equal amount of R1234yf is more than triple the cost of R134a. Speaking of costs, 2026 will probably be rough for car sales, as pricing and market instability may place new vehicles out of reach for many consumers.