Gas Fired Central A/C
Had a short run in the DC metro area from the early 60s till the mid 70s, but you never see one any longer.
It was promoted by the Natural Gas Industry and gas companies to help them sell gas during the summer months.
It was a big bust, It was complicated and broke down several times as often as electric systems.
It was less powerful and did not dehumidify as well, it had a very hard time getting a house cooled down. A neighbor of ours had a Bryant system and they went away in the summer and turned the house temp up about 15 F, she said it took over two days to get the temp back down to 72F, she said she would never do that again.
But the biggest problem was it cost more to run, almost 50% more than a good all electric system. Initially the gas company gave you 40% all the gas your home used every year, year around to get people to buy these over priced under powered systems, but once the energy crisis hit in the early 70s they abruptly took away the discount and as the systems brook down they just disappeared, I have not seen a working one for at least a decade.
John