One History
The rediscovery of carbon dioxide (CO2) as a refrigerant began in the late 1980s. Following an initial research phase that lasted until the early 1990s and the subsequent development of prototypes, mass production of machinery finally commenced in the early 2000s.
The research originated at the University of Trondheim (Norway), spearheaded by Professor Lorentzen (1915-1995). Initially, the research focused on developing small heat pumps for domestic hot water. These studies led the renowned Japanese company Denso to develop “Ecocute” heat pumps, quickly followed by other Japanese manufacturers. The next phase of research concerned Mobile Air Conditioning (MAC) systems, though this did not lead to immediate industrialization.
Starting in 1996, the development of refrigeration systems using CO2 began in Italy. This application had not been initially considered, as it was deemed complex and commercially unattractive. Having personally participated in this evolution as one of the key figures, I would like to use this blog to reconstruct the history of CO2 refrigeration system development.
Today, CO2 has become the standard fluid for commercial refrigeration (with over 100,000 systems installed across all continents) and a preferred choice in industrial refrigeration—with capacities up to 2 MW—as well as in high-capacity heat pumps for district heating.
To keep things engaging, I will publish a short article every ten days; I have summarized the entire journey into seven chapters. Later, for those wishing to dive deeper, I will make available a complete and more extensive collection, enriched with further technical notes.
Acknowledgements. The persons listed below have contributed substantially to the events described in this history. A big “thank you “ to all of them.
Silvia Minetto - ITC-CNR (I)
Gerald Heinzmann – Kaeltering (CH)
Kurt Goetz - Kaeltering (CH)
Raphael Gerber – Frigoconsulting (CH)
Jonas Schoenenberger – Frigoconsulting (CH)
Massimo Lorenzi – Realtime srl (I)
Armin Hafner – Sintef (N)
Petter Neksa – Sintef (N)
Finally, a special “thank you” to eng. Mario Dorin