Which refrigerant is historically associated with older central air systems and is a CFC?

Which refrigerant is historically associated with older central air systems and is a CFC?

• A. R-134a
• B. R-22
• C. R-12
• D. R-410A

Answer: (C)

Older central air systems used refrigerants that contained chlorine, which is a hallmark of chlorofluorocarbons that deplete the ozone layer. R-12 is the classic CFC that was widely used in those older systems. Because of environmental concerns, R-12 was phased out and replaced with refrigerants that do not contain chlorine, such as R-134a. The other refrigerants listed belong to different classes: R-134a is an HFC without chlorine, R-22 is an HCFC with chlorine but not a CFC and is being phased out as well, and R-410A is an HFC blend used in newer equipment.

Older central air systems used refrigerants that contained chlorine, which is a hallmark of chlorofluorocarbons that deplete the ozone layer. R-12 is the classic CFC that was widely used in those older systems. Because of environmental concerns, R-12 was phased out and replaced with refrigerants that do not contain chlorine, such as R-134a. The other refrigerants listed belong to different classes: R-134a is an HFC without chlorine, R-22 is an HCFC with chlorine but not a CFC and is being phased out as well, and R-410A is an HFC blend used in newer equipment.