After reaching the required recovery level on a system that is charged with an A2L refrigerant, what should be done?

• A. The system can be left as is
• B. Replace the receiver
• C. A nitrogen sweep should be done to remove any residual refrigerant vapor
• D. Repressurize with air

Answer: (C)

Residual refrigerant vapor can remain in the system even after you’ve reached the required recovery level. For A2L refrigerants, which are mildly flammable, it’s important to purge that remaining vapor with a dry nitrogen sweep. The inert nitrogen displaces the refrigerant vapor, reducing flammability risk and making it safer to service or repair the system. Leaving it as-is could leave flammable vapors in the lines, and replacing the receiver or repressurizing with air doesn’t address the vapor safely (air isn’t inert and can introduce oxygen and moisture). So, the best practice is to perform a nitrogen sweep to purge the residual refrigerant vapor.