R-22, also known as chlorodifluoromethane, is a chlorofluorocarbon (CFC) refrigerant widely used in HVAC systems for decades that depletes atmospheric ozone. Developed in the 1930s, R-22 became the standard for air conditioning and heat pump systems through the 1990s due to its excellent thermodynamic properties and low cost. The Montreal Protocol mandated its phaseout beginning in 2004, with complete production bans in developed nations by 2020, though recovery and recycling of existing R-22 remains legal.
Performance Characteristics
R-22 operates effectively across a wide temperature range with critical temperature of 369.3K and 49.8 bar pressure rating. It mixes readily with mineral and alkylbenzene oils commonly found in older systems. Atmospheric lifetime of 11.8 years and ozone depletion potential of 0.05 made R-22 environmentally problematic compared to modern alternatives.
Compliance and Replacement
Systems using R-22 manufactured before 2004 cannot be serviced with new R-22; only reclaimed or recycled refrigerant is permitted. Many technicians recommend system replacement with R-410A or R-407C alternatives when R-22 units require major repairs. Retrofit options exist but often require oil changes and component modifications.