In this episode of Taking the Temperature of HVAC, Jamie Kitchen sits down with John Broughton and Jorg Saar to explore the fascinating history of refrigerants—from harvested ice, water, ammonia, and CO2 to CFCs, HCFCs, HFCs, and today’s low-GWP alternatives.

The conversation traces how refrigeration evolved from ice houses and early evaporative cooling to mechanical systems in homes, factories, ships, and supermarkets. Along the way, the team shares stories from the field, reflects on the rise and fall of refrigerants like R-12, R-22, R-11, and R-502, and discusses why the industry is once again adapting to a new generation of refrigerants, including propane, CO2, R-32, and A2Ls.

It’s a practical, entertaining look at how the past continues to shape the future of HVAC—and why understanding refrigerant history matters more than ever.