Often confused · Small-appliance recovery
The 80/90% recovery rule for small appliances
The 80/90% rule for small appliances says recovery equipment made on or after November 15, 1993 must recover 90% of the charge when the appliance's compressor runs and 80% when it doesn't, equipment made before that date must recover 80% either way, and pulling the appliance down to 4 inches of mercury vacuum satisfies every case (40 CFR 82.156(b), eCFR as of October 5, 2026).
Part of Small-appliance recovery in the Study guide
The machine with no readable date
A used recovery machine comes with the van, and its data label is worn past reading. You can't tell whether it was built before or after November 15, 1993, so you can't tell whether a running compressor would hold you to 80% or 90%. The 4 inHg option settles it: take the small appliance down to 4 inches of mercury vacuum and the requirement is met in every cell of the grid below, whatever the machine's age.
That's the practical reading of the rule. A percentage is hard to prove on a job without weighing what came out; a vacuum reading is right there on the gauge. The percentages still matter, because the exam asks for them, and they turn on two facts only.
The same move helps when the date is known but the compressor's state isn't clear, such as a unit that starts and trips: the 4 inHg endpoint takes the question off the table.
The whole rule in one grid
Type I recovery requirement, 40 CFR 82.156(b)
| Recovery equipment made | Appliance compressor runs | Appliance compressor doesn't run |
|---|---|---|
| Before Nov 15, 1993 | 80%, or 4 inHg vacuum | 80%, or 4 inHg vacuum |
| On or after Nov 15, 1993 | 90%, or 4 inHg vacuum | 80%, or 4 inHg vacuum |
Percentages are of the refrigerant charge in the small appliance. Source: 40 CFR 82.156(b), eCFR as of October 5, 2026.
How the grid gets tested
Two variables, plenty of padding
Every Type I recovery question comes down to two facts: when the recovery machine was made, and whether the appliance's compressor runs. Refrigerant names, appliance ages and charge sizes are padding as far as the percentage goes. The date belongs to the recovery equipment; the appliance's own age never enters the rule.
“Old machine 80, new machine 90” misses a cell
That shortcut gets one combination wrong. A post-1993 machine on a dead compressor is still 80%. A sturdier hook: 90% needs a post-1993 machine and a running compressor, and losing either one drops you to 80%.
Why a dead compressor costs ten points
A running compressor helps move the charge toward your recovery connection. A stopped one leaves refrigerant dissolved in its oil and stranded on the far side, and the rule accepts a lower figure rather than demanding the impossible. Getting at that refrigerant is a technique question, covered on system-dependent vs self-contained recovery.
Which appliances it covers
Only small appliances: factory-sealed, with five pounds of refrigerant or less (40 CFR 82.152, eCFR as of October 5, 2026). If the unit in a stem fails that definition, the grid is the wrong tool, so check what counts as a small appliance first. A field-charged split system falls outside it however small its charge, because its refrigerant went in on site.
Run the grid on these
Underline the recovery machine's date and the compressor's state in each stem before reading the options.
0 right · 0 of 8 answered
For non-operational air conditioning units, recovery equipment must be able to achieve what specifications in refrigerant recovery?
Why each option is right or wrong
Answer: B. 80 percent of the refrigerant or achieving 4 inches of vacuum.
- AWrong: 85% and 3 inHg aren't Type I requirements.
- BCorrect: for a small appliance with an inoperative compressor, the rule is 80% recovery or a 4 inHg vacuum.
- CWrong: 75% and 6 inHg aren't part of the Type I rules.
- DWrong: 90% applies when the compressor works (with equipment made on or after Nov. 15, 1993), not when it is inoperative.
For a small appliance with a non-operating compressor, recovery equipment must recover 80% of the refrigerant or reach a 4-inch vacuum.
How should a technician determine if a small appliance recovery is complete when using the 4 inches of mercury vacuum standard?
Why each option is right or wrong
Answer: C. Isolate the system and verify the vacuum remains stable
- AWrong: weighing the appliance isn't how you verify the 4 inHg standard; that standard is measured with a gauge.
- BWrong: a nitrogen pressure test checks for leaks, not whether recovery is complete.
- CCorrect: isolate the appliance and watch the gauge; if 4 inHg holds without rising, recovery is complete.
- DWrong: running a set extra time proves nothing; the gauge reading is what counts.
To verify that a 4 inches of mercury vacuum has been achieved, the technician should isolate the recovery device from the small appliance and observe if the system pressure rises. If it remains stable at 4 inches of mercury vacuum, the recovery is complete.
What should a technician do if they notice the pressure rises after achieving a vacuum during small appliance recovery?
Why each option is right or wrong
Answer: D. Repeat the recovery process until the vacuum remains stable
- AWrong: a pressure rise means refrigerant is still coming out of the oil or a component, so recovery isn't finished.
- BWrong: adding nitrogen dilutes the remaining refrigerant and doesn't recover it.
- CWrong: heating the compressor can help release refrigerant, but stopping right after leaves the job unfinished.
- DCorrect: keep recovering until the vacuum holds, since rising pressure shows refrigerant is still boiling out.
A rising pressure after achieving vacuum indicates that refrigerant is still migrating from components or oil within the system. The technician should repeat the recovery process until a stable vacuum is maintained, ensuring all recoverable refrigerant has been removed.
A technician is recovering refrigerant from a small appliance with a non-running compressor. To reach the 80% recovery requirement, which action should the technician take?
Why each option is right or wrong
Answer: D. Tap both the high and low sides of the system.
- AWrong: low-side access alone leaves refrigerant stranded on the high side when the compressor can't move it.
- BWrong: pushing refrigerant out with nitrogen contaminates it and can release it; the fix is better access, not pressure.
- CWrong: high-side access alone leaves refrigerant trapped on the low side.
- DCorrect: with a non-running compressor, refrigerant is trapped on both sides, so you tap both the high and the low side to reach the 80% endpoint.
With the compressor not running, refrigerant gets trapped on one side of the capillary tube, so install access on both the high and low sides to reach the 80% recovery requirement.
When performing system-dependent recovery on a small appliance with a non-operating compressor and a factory charge of 2.0 lbs, what is the required minimum recovered amount?
Why each option is right or wrong
Answer: A. 1.6 lbs
- ACorrect: with a non-operating compressor the target is 80%, and 2.0 lb × 0.80 = 1.6 lb.
- BWrong: 2.00 lb is 100%, which isn't required and usually isn't achievable.
- CWrong: 1.50 lb is only 75%, below the 80% requirement.
- DWrong: 1.80 lb is 90%, which is the target when the compressor works, not when it is inoperative.
For a non-operating compressor, EPA rules dictate recovering 80% of the nameplate charge when using system-dependent equipment. Multiplying the 2.0 lbs charge by 80% equals 1.6 lbs.
A technician uses a self-contained recovery machine on a factory-sealed small appliance containing 3 pounds of R-410A. The compressor is inoperative. What is the minimum recovery requirement?
Why each option is right or wrong
Answer: B. Recover 80% of total charge
- AWrong: 10 inHg is a Type II evacuation level for larger appliances, not a small-appliance standard.
- BCorrect: for a small appliance with an inoperative compressor, recover 80% of the charge (or reach a 4 inHg vacuum).
- CWrong: 0 psig applies to non-major repairs on larger appliances, not small-appliance recovery.
- DWrong: 15 inHg is a Type II level for large medium-pressure appliances, not a small-appliance standard.
For small appliances with inoperative compressors, technicians must recover 80% of the refrigerant. Vacuum targets like 10 or 15 inches of mercury apply to larger appliances.
A technician uses a recovery machine made in 1992 on a 2022 window air conditioner with a working compressor. What is the minimum requirement?
Why each option is right or wrong
Answer: A. Recover 80% of the charge, or reach 4 inches of Hg vacuum
- ACorrect: equipment made before November 15, 1993 must recover 80% or reach 4 inches of Hg vacuum.
- BThe date that matters is the recovery equipment's manufacture date, not the appliance's.
- CNeither 95% nor 10 inches is a small-appliance requirement in the regulations.
- DThe 90% figure applies only to recovery equipment made on or after November 15, 1993.
For small appliances, the November 15, 1993 date refers to when the recovery equipment was made. Pre-1993 equipment must recover 80% of the charge or evacuate to 4 inches of Hg vacuum, whether or not the compressor runs.
Using recovery equipment made in 2019, a technician recovers R-134a from a household refrigerator whose compressor runs normally. What is the minimum requirement?
Why each option is right or wrong
Answer: C. Recover 90% of the charge, or reach 4 inches of Hg vacuum
- A10 inches is a Table 1 level for larger appliances; small appliances use 4 inches.
- B80% applies to post-1993 equipment only when the appliance compressor is not operating.
- CCorrect: post-1993 equipment on an appliance with a working compressor must recover 90% or reach 4 inches.
- DBoth figures are wrong here: the compressor works and 15 inches is not a small-appliance level.
Recovery equipment made on or after November 15, 1993 must recover 90% of the charge when the appliance compressor operates and 80% when it does not. Evacuating to 4 inches of Hg vacuum meets the requirement in either case.
More practice across all four sections: Practice test · Timed mock
Key takeaways
- The November 15, 1993 cut-off is the recovery machine's manufacture date.
- 90% only for a post-1993 machine on a running compressor; every other combination is 80%.
- 4 inHg vacuum satisfies the requirement in all four cases, which helps when a machine's date can't be read.
- The wider Type I recovery picture is in small appliance recovery.
- Source for the figures above: 40 CFR 82.156(b), eCFR as of October 5, 2026.