After Nov. 11, 1993, what is the requirement for recovering more than 200 lbs of R-22?

The requirement for recovering more than 200 lbs of R-22 involves taking the system down to a vacuum level of 10 inches of mercury (hg). This standard is in place to ensure that all refrigerant is effectively removed from the system, minimizing the risk of releasing any substances into the atmosphere, which is particularly important for substances classified as ozone-depleting.

Achieving a vacuum of 10" hg indicates that the system has been sufficiently evacuated to remove the majority of the R-22, aligning with regulations aimed at promoting environmental safety and compliance with the Clean Air Act. This requirement reflects the industry's best practices for refrigerant recovery, ensuring that proper measures are taken to address the environmental impacts associated with refrigerant release.

Other methods, such as taking the system down to 0 psig or allowing it to remain at atmospheric pressure, would not effectively meet the recovery standards and could result in residual refrigerant in the system. Therefore, achieving a vacuum of 10" hg is the accepted procedure for ensuring thorough recovery of the refrigerant.