We cover:

• The basics of evaporative cooling
• Benjamin Franklin’s experiments with ether and alcohol
• The birth of closed-loop systems
• Early refrigerants like ammonia and methyl chloride
• The game-changing introduction of Freon (R12)
• Environmental concerns and the phaseout of CFCs and HCFCs
• The rise and fall of R410A
• Modern A2L refrigerants and their properties
• The ongoing use of CO2 and ammonia in specialized applications