An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Required Level of Evacuation of Appliances

This table lists levels of evacuation for various types of refrigeration and air conditioning equipment manufactured either before or after November 15, 1993.

Type of Appliance Inches of Hg vacuum
(relative to standard atmospheric pressure of 29.9 inches Hg)
  Using pre-1993 equipment Using post-1993 equipment
Very high-pressure appliance 0 0
High-pressure appliance, or isolated component of such appliance, with a full charge of less than 200 pounds of refrigerant 0 0
High-pressure appliance, or isolated component of such appliance, with a full charge of 200 pounds or more of refrigerant 4 10
Medium-pressure appliance, or isolated component of such appliance, with a full charge of less than 200 pounds of refrigerant 4 10
Medium-pressure appliance, or isolated component of such appliance, with a full charge of 200 pounds or more of refrigerant 4 15
Low-pressure appliance 25 mm Hg absolute 25 mm Hg absolute