Before an appliance is opened for service or disposal, its refrigerant must be recovered down to a required level of vacuum. These levels come up on the Type II and Type III sections of the EPA 608 exam, and they’re easy to mix up. Here’s the table from the regulation (40 CFR 82.156, Table 1), and how to read it.

The table

Levels are in inches of mercury vacuum, except low-pressure appliances, which use millimeters of mercury absolute. The columns depend on when the recovery or recycling equipment was made, not when the appliance was made.

How to read it

1. Find the pressure class. Most residential and light commercial systems (R-22, R-410A, R-134a) are high-pressure. Centrifugal chillers using R-123 or R-11 are low-pressure.
2. Check the full charge. The 200-pound line splits large systems from small ones.
3. Check the recovery equipment’s date. Newer equipment must pull a deeper vacuum on the larger systems.

A useful pattern: newer recovery equipment never has a lower requirement than older equipment, and larger charges never have a lower requirement than smaller ones in the same class.

Small appliances are different

Small appliances (factory-sealed with 5 pounds or less, covered by Type I) don’t use Table 1. With recovery equipment made on or after November 15, 1993, you must recover 90% of the refrigerant if the compressor runs or 80% if it doesn’t. Equipment made before that date must recover 80%. Either way, evacuating to 4 inches of mercury vacuum also meets the requirement.

When a system can’t reach the level

If leaks make it impossible to reach the required level, or reaching it would contaminate the refrigerant, the rules allow recovery to stop at the lowest level that can be reached, within limits. Check the current regulation for the details before relying on this.

Test yourself

Practise more: Type II practice test, Type III practice test and Type I practice test.