You bring up some painful memories.
It was the mid 80s when the HVACR industry saw the signs that we would need to move away from CFCs. Automotive AC was still running R12 at the time because the lower pressures were better for the hot and cramped space available (small condensers, etc.), so HFC134A was the logical choice. They went with PAG (polyalkylene glycol) oil because it was available earlier than POEs.
Stationary direct expansion (DX) systems had moved mostly to R22 by the late 60s, so an R22 substitute was needed. Because 22 is an HCFC, and less ozone depleting than CFCs (5% as much as R12), the timetable for phaseout was longer. In refrigeration, we even moved from single stage R502 to compound and injection cooled R22 systems for several years because it looked like we might be able to keep 22 a bit longer and there was not a good HFC just yet. R404A and R507 eventually replaced 502, but not for much longer.
As an eventual R22 substitute, R410A and R407c (both HFCs) were early candidates. 410 runs much higher pressure than either 22 or 407, but that works well in smaller systems. 407c was used in larger commercial units with larger components, especially semi-hermetic compressor applications, where the high pressure of 410 would have been problematic.
Eventually HFCs will also be gone, so don't get too comfortable just yet.
Been around awhile. Large industrial plants (say 2 million BTU's per hour and up) can use propane cost effectively for both heating and cooling. The liquid propane is evaporated to produce refrigeration for the offices and processes that need cooling, and then the vaporized propane is fed into large furnaces for heating purposes.