Second Stage Refrigerant Development Time

Non azeotropic refrigerants began to be used in the 1960s.
The air conditioning industry has grown from a young age to a multi billion dollar industry, using the aforementioned refrigerants. By 1963, these refrigerants accounted for 98% of the total organic fluorine industry production.
By the mid-1970s, concerns about the thinning of the ozone layer had surfaced, and CFC group substances may have to bear some of the responsibility. This led to the adoption of the Montreal Protocol in 1987, which required the elimination of CFCs and HCFC families. The new solution is to develop the HFC family to play the main role of refrigerants. The HCFC family will continue to be used as a transitional solution and will gradually be phased out. [4]
In the 1990s, global warming posed a new threat to life on Earth. Although there are many factors contributing to global warming, due to the huge energy consumption of air conditioning and refrigeration (buildings in the United States consume about one-third of the total energy consumption), and many refrigerants themselves are greenhouse gases, refrigerants have been included in the discussion scope. Although ASHRAE Standard 34 classifies many substances as refrigerants, only a small portion is used for commercial air conditioning.