It’s a seemingly perfect solution.
The old ammonia systems worked, and some still do to this day.
No environmental problems, in fact ammonia is good FERTILIZER.
The modern technology using PTFE (Teflon) seals and on connections would preclude any leakage problems.
The systems are proven for safe for many decades...................
Oh, I’m not arguing against the use of ammonia as a refrigerant. It has some definite advantages in terms of cost and efficiency. There would be a lot of yammering from the greenies about how ammonia is a dangerous air pollutant; in fact, there already is.
Using PTFEs in seals and such may prove to be a problem when they eventually outlaw those compounds.
Is there still an Arkla/Servel a/c unit available?