What evacuation vacuum level must a technician reach when recovering refrigerant from a high-pressure appliance with a full charge of 200 pounds or more? Answer in under 100 words.

Details / How it works

Before opening or disposing of appliances (except small appliances, MVACs, and MVAC-like appliances), technicians must evacuate refrigerant—including all liquid refrigerant—to the levels in Table 1 of § 82.156, using recovery and/or recycling machine certified pursuant to § 82.158. A technician must verify that the applicable evacuation level has been reached in the appliance or the isolated part before it is opened. Technicians may evacuate either the entire appliance or only the part being serviced if the refrigerant in that part can be isolated to a system receiver.

Numbers & thresholds

All values are inches of Hg vacuum relative to standard atmospheric pressure of 29.9 inches Hg.

Exceptions & edge cases

• If leaks in the appliance make evacuation to the Table 1 levels unattainable or would substantially contaminate the recovered refrigerant, persons opening or disposing of the appliance must isolate leaking from non-leaking components wherever possible, evacuate non-leaking components to the Table 1 levels, and evacuate leaking components only to the lowest level attainable without substantially contaminating the refrigerant (this level may not exceed 0 psig).
• If the maintenance/service/repair is not major (as defined at § 82.152) and no post-service venting will occur, medium-, high-, and very high-pressure appliances need only be evacuated to no higher than 0 psig rather than the deeper Table 1 vacuums.
• For oil changes only, evacuation or pressurization to no higher than 5 psig is acceptable.