The History of Refrigerants: From Early Innovations to Modern Challenges

Refrigerants have played a pivotal role in transforming refrigeration and air conditioning technologies, from early experiments to modern-day solutions addressing environmental concerns.

The Dawn of Mechanical Refrigeration

Early Innovations in Refrigeration

• 1834: Jacob Perkins built the first practical refrigeration machine using ether as the refrigerant in a vapor compression system.
• 1866 & 1873: Carbon dioxide (CO₂) and ammonia (NH₃) were introduced as refrigerants.
• Other early refrigerants included:
  • Chemical cyanide (a mixture of petroleum ether and naphtha)
  • Sulfur dioxide (R-764)
  • Methyl ether

These early refrigerants were primarily used in industrial processes, while most food preservation relied on ice collected in winter or industrially produced ice.

Refrigeration Expands to Air Conditioning

In the early 20th century, refrigeration systems began serving air conditioning purposes:

• The Plum Building in San Antonio, Texas became the first fully air-conditioned high-rise office building.

The Era of CFCs and the Rise of Modern Refrigeration

Game-Changing Developments

• 1926: Thomas Midgley developed the first chlorofluorocarbon (CFC) machine using R-12 as the refrigerant. CFCs were:

  • Non-combustible
  • Less toxic compared to sulfur dioxide
  • Energy-efficient

• 1931: CFC machines entered commercial production, soon reaching homes.

• Around this time, Willis Carrier introduced the first commercial centrifugal chiller, ushering in the modern refrigeration and air conditioning era.

Introduction of Halogenated Hydrocarbon Refrigerants

Throughout the 1930s, DuPont trademarked halogenated hydrocarbon refrigerants under the name "Freon." These refrigerants were:

• Non-toxic
• Non-combustible
• Adaptable to various temperature ranges

This period saw the introduction of refrigerants like CFC-11, CFC-12, CFC-113, CFC-114, and HCFC-22.

Advances in Refrigerant Technology

• 1950s: Azeotropic refrigerants came into use.
• 1960s: Non-azeotropic refrigerants followed, further improving cooling efficiency.
• By 1963, refrigerants accounted for 98% of the total organic fluorine industry production.

Environmental Concerns and the Shift to HFCs

The Ozone Layer Crisis

• Mid-1970s: Concerns over ozone layer thinning emerged, with CFCs identified as a significant contributor.
• 1987: The Montreal Protocol was adopted to phase out CFCs and HCFCs.
• HFCs (hydrofluorocarbons): Developed as environmentally safer alternatives, HCFCs were used as transitional refrigerants but were also scheduled for phase-out.

Global Warming and Modern Challenges

• 1990s: The focus shifted to global warming, highlighting the energy consumption of refrigeration systems and the greenhouse gas potential of many refrigerants.
• Buildings in the U.S. accounted for approximately one-third of total energy consumption, further spotlighting the impact of refrigerants.
• While many substances were classified as refrigerants under ASHRAE Standard 34, only a small percentage were widely used in commercial air conditioning systems.