What gets tested · Type II
Required evacuation levels on the EPA 608
Required evacuation levels are the vacuum a Type II or Type III appliance must reach before it's opened for a major repair or sent for disposal, and three facts pick the level: the pressure class, whether the charge is under 200 lb, and when the recovery equipment was made (40 CFR 82.156(a), eCFR as of October 5, 2026). Twelve cells look like a memorization job; they hold five distinct values.
The evacuation table
Required levels of evacuation, inches of mercury vacuum unless noted
| Appliance | Recovery equipment made before Nov 15, 1993 | Made on or after Nov 15, 1993 |
|---|---|---|
| Very-high-pressure | 0 | 0 |
| High-pressure, under 200 lb | 0 | 0 |
| High-pressure, 200 lb or more | 4 | 10 |
| Medium-pressure, under 200 lb | 4 | 10 |
| Medium-pressure, 200 lb or more | 4 | 15 |
| Low-pressure | 25 mm Hg absolute | 25 mm Hg absolute |
40 CFR 82.156(a), Table 1, eCFR as of October 5, 2026. The 200-lb split counts the charge of the appliance, or of the isolated component being serviced. Small appliances follow their own rule, covered in small-appliance recovery.
The newer column on one gauge
Reading the table in four moves
Name the pressure class
Saturation pressure at 104 °F: low below 45 psia, medium 45 to 170, high 170 to 355, very high above 355 (40 CFR 82.152, eCFR as of October 5, 2026). R-134a is medium, R-22 high, R-123 low.
Check the charge against 200 lb
Use the full charge of the appliance, or of the isolated component if only that section is opened. Only the high- and medium-pressure rows split at 200 lb. A 350-lb R-22 system whose isolated 120-lb section is opened for a major repair reads the under-200-lb row.
Read the recovery machine's date
November 15, 1993 is the manufacture date of the recovery or recycling equipment. The appliance's age never enters the table; the same point is made at length on the 80/90% recovery rule.
Check whether an exception applies
A non-major repair, or a leaky appliance that can't reach the table level, has its own endpoint, covered below.
When the table isn't the target
The table is shared by the Type II section and the Type III section, and it governs two events only: disposal and major repairs. Two lookups for practice: a 300-lb R-134a process cooler recovered with a 2012 machine lands in the medium, 200-lb-or-more row of the newer column, 15 inHg; an R-23 stage of a cascade system needs 0 inHg with any machine.
What makes a repair major
A major repair means removing the compressor, condenser, evaporator or an auxiliary heat-exchange coil, or uncovering an opening of more than 4 square inches of flow area for more than 15 minutes (40 CFR 82.152, eCFR as of October 5, 2026). Anything short of that is non-major.
Non-major repairs and leaky systems
Before a non-major repair, medium-, high- and very-high-pressure appliances may be evacuated to 0 psig, and low-pressure appliances pressurized to 0 psig. Before an oil change, the appliance may stay at 5 psig or below (40 CFR 82.156(a), eCFR as of October 5, 2026).
If leaks make the table level unattainable, evacuate to the lowest level reachable without substantially contaminating the refrigerant, and never above 0 psig (40 CFR 82.156(a), eCFR as of October 5, 2026).
For appliances holding 5 to 50 lb sent for disposal, the technician keeps records of the recovery for 3 years (40 CFR 82.156(a)(3), eCFR as of October 5, 2026).
Units the table mixes
Inches of mercury vacuum count down from atmospheric pressure, about 29.92 inHg at sea level; millimeters of mercury absolute count up from zero, with 25.4 mm Hg to the inch; and 1 mm Hg is 1,000 microns. So 15 inHg vacuum at sea level leaves roughly 14.9 inHg, or about 379 mm Hg, absolute: a long way above the low-pressure row.
Stale values in old prep sheets
Some older study sheets print a different figure for the low-pressure row with pre-1993 recovery equipment. The current table shows the same absolute value in both columns (40 CFR 82.156(a), eCFR as of October 5, 2026); go by the current table.
Find the row before the column
Settle the pressure class and the 200-lb split before you look at the equipment date.
0 right · 0 of 15 answered
What is the required evacuation level for a high-pressure appliance holding 15 pounds of refrigerant?
Why each option is right or wrong
Answer: C. 0 psig (0 inches of mercury vacuum)
- AWrong: 10 inHg applies to medium-pressure appliances under 200 lb, or high-pressure appliances of 200 lb or more, with newer equipment.
- BWrong: 4 inHg is the alternative Type I target and the older-equipment level for medium-pressure and larger high-pressure appliances.
- CCorrect: a high-pressure appliance under 200 lb must be evacuated to 0 inHg (0 psig) with recovery equipment of any date.
- DWrong: 15 inHg applies to medium-pressure appliances of 200 lb or more with newer recovery equipment.
A high-pressure appliance with less than 200 pounds of refrigerant must be evacuated to 0 psig (0 inches of mercury vacuum), whatever the recovery equipment's manufacture date.
Under EPA's definition, which action is a 'major repair' in refrigeration systems?
Why each option is right or wrong
Answer: D. Evaporator coil replacement
- AWrong: adjusting a thermostat doesn't open the refrigerant circuit.
- BWrong: reopening a service valve isn't removing a major component.
- CWrong: cleaning condenser coils doesn't open the circuit.
- DCorrect: removing the evaporator coil (like the compressor, condenser, or auxiliary heat-exchange coil) is a major repair.
EPA defines a major repair as one that removes the compressor, condenser, evaporator or an auxiliary heat exchanger coil, so replacing the evaporator coil qualifies.
A technician is servicing a commercial supermarket rack system equipped with multiple isolation valves. Under EPA Section 608 regulations, which of the following maintenance procedures is strictly classified as a major repair?
Why each option is right or wrong
Answer: B. Replacing the primary evaporator coil in the system
- AWrong: a filter-drier isn't one of the major components named in the definition.
- BCorrect: removing the evaporator coil is a major repair, so the major-repair evacuation levels apply.
- CWrong: a pressure switch isn't a major component, especially when it can be isolated.
- DWrong: a TXV isn't one of the major components (compressor, condenser, evaporator, auxiliary heat-exchange coil).
The EPA defines a major repair as any service involving the removal of the compressor, condenser, evaporator, or auxiliary heat exchanger coil.
When recovering refrigerant from a low-pressure system, what final recovery vacuum level must be achieved?
Why each option is right or wrong
Answer: A. 25 mm Hg absolute (25 torr)
- ACorrect: for low-pressure appliances the required recovery level is 25 mm Hg absolute (about 29 inches of vacuum), whatever the recovery equipment's date.
- BWrong: 500 microns is a common dehydration target before charging (industry practice, not in the rule text), not the recovery level the rules set.
- CWrong: 10 inches of vacuum is the level for some high-pressure appliances of 200 lb or more, far too shallow for a low-pressure chiller.
- DWrong: 0 psig would leave most of the refrigerant in a low-pressure chiller, which runs below atmospheric pressure.
Low-pressure appliances must be evacuated to 25 mm Hg absolute (25 torr) before they are opened or disposed of.
At an altitude where local atmospheric pressure is 635 mm Hg absolute, a low-pressure appliance requires evacuation to 25 mm Hg absolute. What minimum gauge reading must be achieved?
Why each option is right or wrong
Answer: A. 610 mm Hg
- ACorrect: a vacuum gauge reads atmosphere minus absolute pressure, so 635 - 25 = 610 mm Hg of vacuum.
- BWrong: 660 adds the values instead of subtracting.
- CWrong: 25 mm Hg is the absolute target, not what a vacuum gauge reads.
- DWrong: 735.4 subtracts from sea-level atmosphere (about 760 mm Hg) instead of the local 635 mm Hg.
Gauge vacuum equals local atmospheric pressure minus absolute pressure: 635 − 25 = 610 mm Hg vacuum.
If the pressure in an HVAC system rises from 0.8 mm Hg to above 2.3 mm Hg after it is isolated under vacuum, the system:
Why each option is right or wrong
Answer: C. should undergo a leak test
- AWrong: a system that keeps rising after being isolated under vacuum is not stabilizing; something is entering it.
- BWrong: a rise like this is the trigger for more testing, not a sign that testing is done.
- CCorrect: when pressure rises past the limit after the system is isolated under vacuum, air is leaking in (or refrigerant is still boiling out), so the system should be leak tested; the 0.8 to 2.3 mm Hg figures are the exam key.
- DWrong: a sealed, dry system should hold its vacuum, so a steady rise is outside normal parameters.
A rise past this limit after isolation means air is leaking in or refrigerant is still boiling out, so leak-test the system. The 0.8 to 2.3 mm Hg figure is exam key and industry practice, not in the rule text.
What is the proper method for checking if a high-pressure system has been properly evacuated?
Why each option is right or wrong
Answer: C. Close the valve to the vacuum pump and observe if the vacuum holds steady
- AWrong: bubbles test for leaks under pressure; they don't show whether evacuation is complete.
- BWrong: listening can't measure a vacuum.
- CCorrect: isolate the pump and watch the gauge; a vacuum that holds shows the system is dry and tight.
- DWrong: time alone means nothing without measuring the level reached.
The proper method for checking if a high-pressure system has been properly evacuated is to close the valve to the vacuum pump, observe if the vacuum holds steady for at least 10 minutes, and verify the micron level with an electronic micron gauge.
After reaching an initial vacuum of 400 microns, a technician isolates the pump to perform a vacuum hold/decay test for a specified hold time of 15 minutes. The gauge rises steadily to 760 microns. What is the calculated rate of rise?
Why each option is right or wrong
Answer: A. 24.0 microns/min
- ACorrect: (760 - 400) / 15 min = 360 / 15 = 24 microns per minute.
- BWrong: the rise is 760 - 400 = 360 microns over 15 minutes, which is 24 per minute, not 15.5.
- CWrong: 36.5 doesn't follow from the readings; 360 microns over 15 minutes is 24 per minute.
- DWrong: 46 doesn't follow from the readings; divide the 360-micron rise by the 15-minute hold time.
Subtract the starting reading from the final one, then divide by the hold time: (760 − 400) / 15 = 24 microns per minute.
What is the primary purpose of evacuation before system charging?
Why each option is right or wrong
Answer: A. Remove air and moisture
- ACorrect: evacuation removes air and moisture, which cause high pressures, acid, and freezing.
- BWrong: evacuation doesn't clean parts; it removes gases and moisture.
- CWrong: evacuation removes gases; charging adds refrigerant afterwards.
- DWrong: evacuation isn't a pressure test.
Evacuation removes air and moisture that can harm system components and reduce efficiency.
When servicing a refrigeration system, what should you avoid doing if the system is in a deep vacuum?
Why each option is right or wrong
Answer: A. energize the compressor.
- ACorrect: never run a hermetic compressor in a deep vacuum; the motor can short or be damaged because the vacuum gives poor insulation and cooling.
- BWrong: a micron gauge is the right tool for measuring a deep vacuum.
- CWrong: fans and blowers are outside the refrigerant circuit and aren't harmed by the system vacuum.
- DWrong: adding refrigerant is how you break the vacuum after evacuation.
Never energize a hermetic compressor while the system is in a deep vacuum: the motor windings can be damaged.
What should be done if moisture is suspected in the refrigeration system of a small appliance?
Why each option is right or wrong
Answer: D. Install a filter-drier in the liquid line
- AWrong: antifreeze has no place in the refrigerant circuit.
- BWrong: raising pressure doesn't remove moisture.
- CWrong: oil doesn't absorb moisture safely; moisture in oil leads to acid.
- DCorrect: a liquid-line filter-drier captures moisture so it can't freeze at the metering device or form acid.
If moisture is suspected in a small appliance system, a filter-drier should be installed in the liquid line. This will absorb the moisture and prevent potential damage to system components caused by acids or ice formation.
When evacuating a rooftop unit equipped with highly hygroscopic POE oil at a 35 °F ambient temperature, which deep vacuum level is necessary to effectively boil trapped moisture?
Why each option is right or wrong
Answer: D. 500 microns
- AWrong: 2500 microns is too shallow as an end point; POE holds moisture tightly and needs a deeper vacuum.
- BWrong: 5000 microns leaves moisture behind, especially with POE oil at low ambient temperature.
- CWrong: 1500 microns is closer but still above the usual dehydration target.
- DCorrect: about 500 microns is the usual dehydration target (exam key and industry practice, not in the rule text), especially with hygroscopic POE oil.
500 microns is the usual dehydration target, especially with hygroscopic POE oil, and a cold ambient doesn't change it (exam key and industry practice, not in the rule text). No EPA rule sets a dehydration level.
A technician halts a low-pressure chiller evacuation at a shallow vacuum of 10 inHg, assuming it matches operating pressure. What is the primary consequence of this procedural error?
Why each option is right or wrong
Answer: A. Excessive venting and EPA violation
- ACorrect: low-pressure appliances must reach 25 mm Hg absolute; stopping at 10 inHg leaves refrigerant that is released when the system is opened.
- BWrong: oil migration isn't the consequence; the problem is refrigerant left behind and released.
- CWrong: a leak test isn't what is at stake, and a shallow vacuum doesn't burst the disc.
- DWrong: purge runtime isn't the issue; the regulatory problem is the refrigerant left in the system.
Stopping at a shallow vacuum leaves a lot of refrigerant vapor inside. A low-pressure appliance must be evacuated to 25 mm Hg absolute before it is opened, so breaking the vacuum at 10 inHg releases refrigerant the rule required you to recover.
Using recovery equipment made in 2015, a technician evacuates a 250-lb R-410A rooftop system before disposal. What level must the system reach?
Why each option is right or wrong
Answer: C. 10 inches of Hg vacuum
- A0 psig is the requirement for a high-pressure appliance holding less than 200 lb.
- B4 inches applies when the recovery equipment was made before November 15, 1993.
- CCorrect: a high-pressure appliance with 200 lb or more needs 10 inches of Hg vacuum with post-1993 equipment.
- D25 mm Hg absolute is the level for low-pressure appliances, not high-pressure R-410A.
R-410A is a high-pressure refrigerant, and this system holds more than 200 lb. With recovery equipment made on or after November 15, 1993, the required evacuation level is 10 inches of Hg vacuum.
A technician uses a recovery machine built in 1991 to evacuate a 120-lb R-134a chiller installed in 2005 before disposal. What evacuation level is required?
Why each option is right or wrong
Answer: A. 4 inches of Hg vacuum
- ACorrect: for a medium-pressure appliance under 200 lb, pre-1993 recovery equipment must reach 4 inches of Hg vacuum.
- B0 psig applies to high-pressure appliances under 200 lb, not medium-pressure R-134a.
- C15 inches applies to medium-pressure appliances of 200 lb or more with post-1993 equipment.
- D10 inches applies to equipment made on or after November 15, 1993; the chiller's age does not set it.
R-134a is a medium-pressure refrigerant, and the table looks at when the recovery equipment was made, not the appliance. Equipment built before November 15, 1993 must reach 4 inches of Hg vacuum on a medium-pressure appliance under 200 lb.
More practice across all four sections: Practice test · Timed mock
Concepts that get mixed up here
Key takeaways
- Three inputs pick a cell: pressure class, charge under or over 200 lb, and the recovery equipment's date (November 15, 1993).
- Low pressure is the only row in absolute units (40 CFR 82.156(a), eCFR as of October 5, 2026).
- A non-major repair can open at 0 psig; an oil change at 5 psig or below.
- Recovery vacuum and dehydration vacuum are different jobs; the second is on deep vacuum and dehydration.