Every age of man has its illusions. Mechanical refrigeration was born with natural refrigerants around 1850, built on the raw elements of the earth: ammonia, sulfur dioxide, and, by 1890, carbon dioxide. It was honest, physical work.

But, as we know, humanity is easily seduced by shortcuts. In the 1930s, the laboratories synthesized the first artificial refrigerants, R12 and R11. These “miracle” molecules were docile, efficient, and obedient. They banished natural fluids to the harsh realms of heavy industry, and we slept comfortably for fifty years, unaware that our chemical miracles were silently tearing a hole in the roof of the world.

The modern refrigeration industry was born based on synthetic refrigerants: CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons). Both contained chlorine, the main enemy of atmospheric ozone.

In the decade between 1990 and 2000, I was on the front lines as the technical manager of a large commercial refrigeration company. I felt the tremors of an industrial earthquake. Nobel-winning minds Rowland, Molina and Crutzen proved that the chlorine in our beloved synthetic gases was gouging the ozone layer. The Montreal Protocol of 1987 struck like a gavel. Today, we can finally call it an environmental triumph, but back then, it was sheer panic.

We scrambled. We fell back on R22 (an HCFC), a lesser evil that was not suitable for all applications, and then the chemists offered us HFCs (hydrofluorocarbons) that are fluids with zero ozone impact. We thought we had found the ultimate chalice, but the earth’s ledger is strict. These new fluids, like R134a and R404A, were monstrous greenhouse gases: releasing just a single kilogram of R404A into the wind was like detonating nearly four tons of CO2 into the atmosphere.

While trying to save the ozone layer, the issue of the greenhouse effect and global warming emerged forcefully. To measure the impact of fluids, the GWP (Global Warming Potential) was defined. New gases such as R404A or R134a, despite being “Ozone Friendly”, turned out to be very powerful greenhouse gases.

Our workshops became chaotic testing theaters. To reduce the charge of synthetic gases, many companies tried the path of indirect systems: a reduced primary circuit cooled a secondary fluid (glycol water) to be pumped to the users. Field analysis, however, revealed insurmountable physical limits:

It was an agonizing labyrinth: power-hungry, prone to corrosion from aggressive acetates, and hopelessly expensive. By the late 1990s, the realization dawned like a harsh winter morning: we didn’t need another synthetic bandage.

While southern Europe remained anchored to the old patterns, news filtered from northern Europe about the use of carbon dioxide (CO2 or R744) as a secondary phase change fluid.

Using CO2 not as a secondary fluid, but directly as a primary, was an obvious idea at that point, It would not been considered an evolution, but a revolution. In 1995, this meant starting a huge industrial effort: it was necessary to design components from scratch that simply did not yet exist on the market.

The path was clear; we needed to return to the origins.