Freon is infinitely more efficient than hydrogen saturated ammonia (absorbsion). As a curious point however, an electric motor powered ammonia ice plant is significantly more efficient than even a Freon 12 plant, using the same horsepower compressor.
Wuuwee, take a hospital, start calculating the relative cost differential between freon A/C and steam boiler driven lithium bromide absorbsion chillers and the calculations progress to a mind numbing degree.
But gas refrigeration cannot be realistically compared to Freon refrigeration because there's a lot more too it than Neanderthal-grade BTU comparisons. Freon refrigeration is light-years more uniform especially in warm to very warm climes. Increasing condenser capacity is easy with Freon. But insanely costly for absorbsion gas. Then there is the problem of how to control and contain tiny, angry, hydrogen atoms.