What is R-134A commonly used as a replacement for?

• A. R-22
• B. R-404A
• C. R-12
• D. R-410A

Answer: (C)

R-134A is commonly used as a replacement for R-12 due to its properties and environmental considerations. R-12, a chlorofluorocarbon (CFC), was found to be harmful to the ozone layer, which led to regulatory actions to phase it out under the Montreal Protocol. R-134A, being a hydrofluorocarbon (HFC), does not deplete the ozone layer, making it a suitable alternative for use in refrigeration and air conditioning systems.

The use of R-134A has been widely adopted in automotive air conditioning and household refrigerators, contributing to its classification as a key replacement for R-12. In contrast, the other choices represent refrigerants that have different applications or environmental impacts and are not directly considered alternatives to R-12.