A technician is disposing of a low-pressure chiller manufactured after November 15, 1993. Which evacuation level generally applies to low-pressure appliances during recovery?

Explanation

Low-pressure appliances must be evacuated to a deep vacuum, expressed as 25 mm Hg absolute, which is roughly 29 inches of mercury vacuum, because these refrigerants boil off only at very low pressures. The 0, 4, and 10 inch Hg figures apply to various high-pressure appliances, not low-pressure chillers. Deep evacuation is required to remove as much low-pressure refrigerant as practical.