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newSchoolWorks.com › VoTechWorks › Transportation › Automotive Technology › Automotive Heating, Ventilation, and Air Conditioning (HVAC) › Lesson 3
TRN-AUTO19-06 · Lesson 3 · 20 clock hours · lab

Refrigerant Identification, Recovery, and Recycling

Objective. Students will connect a refrigerant identifier and recovery/recycling/recharge (RRR) machine to a vehicle, identify the refrigerant type, and perform a complete recovery while recording weight recovered.

⚠ Pending professional review

This lesson, its worked examples and its practice questions has not yet been verified by a certified examiner or master technician in the trade or by a certification or approval body. It is a study draft and may contain errors. Do not use it as instructions for work on a job site or on live equipment. Always follow your instructor, your supervising professional, and current official references and regulations.

VoTechWorks program approval and accreditation are still in progress. Credentials are issued only by the certifying bodies named in each program, after their own exams.

Why Refrigerant Identification and Recovery Matter

Every time you service a vehicle air-conditioning system you are handling a regulated substance. The U.S. Environmental Protection Agency (EPA) prohibits the intentional venting of refrigerants such as R-134a and R-1234yf into the atmosphere under Section 608 of the Clean Air Act. Breaking that rule carries significant civil penalties. Beyond the legal obligation, proper recovery protects the environment, keeps refrigerant costs down, and prevents shop equipment from being contaminated by the wrong refrigerant or by moisture and oil.

Before you touch a service port, you must know what is in the system. Refrigerant identification is not optional—it is the first step every time.

Refrigerant Types You Will Encounter

R-134a has been the dominant automotive refrigerant since it replaced R-12 in the early 1990s. It is a hydrofluorocarbon (HFC) with zero ozone-depletion potential but a significant global-warming potential.

R-1234yf is a hydrofluoroolefin (HFO) introduced around 2014 and now factory-filled in most new vehicles. It has very low global-warming potential. R-1234yf is mildly flammable (ASHRAE A2L classification), so additional precautions apply: keep ignition sources away, use only R-1234yf–rated equipment, and never mix it with R-134a equipment.

Contaminated refrigerant occurs when a system contains air, moisture, wrong refrigerant, or hydrocarbon-based substitutes. Contaminated refrigerant can damage RRR machine seals and desiccant, ruin a compressor, and create a fire or explosion hazard in R-1234yf systems if hydrocarbons are present.

Electronic Refrigerant Identification

A refrigerant identifier compliant with SAE J1771 draws a small sample from the vehicle system and analyzes its composition using infrared spectroscopy or similar technology. The display reports:

Connect the identifier sample hose to the low-side service port only. Use the correct adapter for the vehicle; R-1234yf ports use a different fitting than R-134a ports to prevent cross-connection. Allow the identifier to complete its full analysis cycle—do not interrupt it. Record all values on your lab worksheet before proceeding.

If the identifier flags contamination or shows a purity below the machine's threshold, stop and notify your instructor. Contaminated refrigerant requires separate handling.

Recovery/Recycling/Recharge (RRR) Equipment

An RRR machine certified to SAE J2788 meets EPA efficiency standards: it must recover at least 95% of the refrigerant in the system. The machine automatically:

1. Draws refrigerant from the vehicle into its internal tank

2. Passes the recovered refrigerant through filters and desiccant to remove oil and moisture

3. Weighs the recovered amount on an integrated scale

Because R-134a and R-1234yf must never be mixed, shops maintain dedicated machines and hose sets for each refrigerant. Color coding helps: fittings for R-1234yf are shaped or labeled to prevent accidental cross-connection.

Connecting the RRR Machine — Step by Step

1. Put on PPE. Refrigerant-rated gloves and safety goggles are required before handling any hoses or fittings. Liquid refrigerant can cause frostbite; vapor can displace oxygen in a confined space.

2. Confirm refrigerant identity from the identifier result before selecting the machine.

3. Select correct hoses. High-side hose (typically red) to the high-side port; low-side hose (typically blue) to the low-side port. Verify port fittings match the vehicle.

4. Zero the machine scale if the machine requires a manual tare.

5. Initiate recovery mode per the machine's control panel. The machine will run until pressure in the vehicle system drops to a near-vacuum and stabilizes—this confirms recovery is essentially complete.

6. Monitor the weight display and compare it to the system capacity listed in the service information. Recovery should approach the published capacity (you may recover less if the system was low).

7. Hose removal sequence: Close the machine valves first, then disconnect the hoses from the vehicle ports, high-side first, then low-side. This sequence minimizes refrigerant release from trapped hose volume.

8. Tag the recovery cylinder with vehicle year/make/model, date, refrigerant type, and weight recovered.

9. Complete the refrigerant tracking log. EPA Section 608 regulations require shops to maintain records of refrigerant recovered, including the technician's name and EPA certification number.

Safety Points

EPA Recordkeeping

Shops that service motor vehicle air-conditioning systems must keep records that include the amount of refrigerant recovered from and returned to each vehicle. These records must be available for EPA inspection. The refrigerant tracking log you complete in this lab is the real-world document required by law.

Key terms9

R-134aA hydrofluorocarbon (HFC) refrigerant used in automotive A/C systems since the early 1990s; has zero ozone-depletion potential but high global-warming potential.
R-1234yfA hydrofluoroolefin (HFO) refrigerant with very low global-warming potential, mildly flammable (ASHRAE A2L), used in most new vehicles since approximately 2014.
Refrigerant identifierAn electronic instrument compliant with SAE J1771 that analyzes a refrigerant sample and reports type, purity percentage, and contamination flags.
RRR machineRecovery/Recycling/Recharge machine certified to SAE J2788; removes refrigerant from a vehicle, filters it, weighs it, and stores it for reuse.
SAE J2788The SAE standard specifying minimum performance requirements for RRR equipment, including a recovery efficiency of at least 95%.
Purity percentageThe proportion of the target refrigerant in a sample; most RRR machines require 98% or greater purity before accepting refrigerant into their storage tanks.
Refrigerant tracking logA written record required by EPA Section 608 regulations documenting the amount of refrigerant recovered from and returned to each vehicle serviced.
Contaminated refrigerantRefrigerant that contains air, moisture, hydrocarbon substitutes, or a different refrigerant type; can damage equipment and create safety hazards, especially in R-1234yf systems.
Section 608The section of the Clean Air Act that prohibits intentional venting of refrigerants and requires technician certification and recordkeeping for motor vehicle A/C service.

Worked examples4

1. The service information for a 2019 sedan lists the A/C system refrigerant capacity as 1.40 lb of R-134a. After recovery the RRR machine scale shows 1.33 lb recovered. What is the percentage of capacity recovered, and does this meet the SAE J2788 95% recovery requirement?
  1. Divide weight recovered by system capacity: 1.33 ÷ 1.40 = 0.9500
  2. Convert to a percentage: 0.9500 × 100 = 95.0%
  3. Compare to the SAE J2788 minimum of 95%: 95.0% ≥ 95%, so the requirement is met.
Answer: 95.0% recovered; this exactly meets the SAE J2788 minimum recovery efficiency of 95%.
2. A 2022 SUV has a listed R-1234yf capacity of 0.90 lb. The machine recovers 0.76 lb. What percent was recovered, and is it within the 5% tolerance allowed by your lab checklist (which defines acceptable as recovering at least 95% of capacity)?
  1. Divide recovered by capacity: 0.76 ÷ 0.90 = 0.8444
  2. Convert to percentage: 0.8444 × 100 = 84.4%
  3. The lab checklist requires weight recovered within 5% of system capacity, meaning at least 95% recovery: 84.4% < 95%.
  4. Conclusion: recovery is below the acceptable threshold; the system was significantly low before service, or recovery was incomplete. Report to instructor and re-evaluate.
Answer: 84.4% recovered — below the 95% threshold. This indicates the system was likely already low on refrigerant or recovery was not completed properly.
3. Your refrigerant tracking log requires you to record weight recovered in both pounds and ounces. The scale reads 1.15 lb. Convert this to pounds and ounces.
  1. Identify the decimal portion: 1.15 lb — the whole-pound portion is 1 lb.
  2. Convert the decimal portion to ounces: 0.15 lb × 16 oz/lb = 2.4 oz.
  3. Combine: 1 lb 2.4 oz.
Answer: 1 lb 2.4 oz (or approximately 1 lb 2⅜ oz).
4. A shop recovered refrigerant from three vehicles in one day: 1.20 lb, 0.85 lb, and 1.50 lb. What is the total weight of refrigerant recovered that must be entered in the daily refrigerant tracking log?
  1. Add all three amounts: 1.20 + 0.85 = 2.05 lb.
  2. Add the third: 2.05 + 1.50 = 3.55 lb.
Answer: 3.55 lb total refrigerant recovered for the day.

The math in this lesson2

Learners compute percent of rated refrigerant capacity recovered against a 5 percent tolerance.
7.RP.3N-Q.1
Brush up in the math halls at newSchoolWorks.com:
In class: Identify the refrigerant in two assigned vehicles using an electronic refrigerant identifier; record type, purity percentage, and any contamination flags on a lab worksheet. · Connect the RRR machine to the vehicle service ports using correct high- and low-side hoses, initiate recovery, monitor weight on the integrated scale, and document pounds recovered against estimated system capacity from the service information. · After recovery, demonstrate proper hose removal sequence to prevent refrigerant release, tag the recovered refrigerant cylinder with vehicle and date, and complete the refrigerant tracking log required for EPA recordkeeping.
Materials: Refrigerant identifier (SAE J1771 compliant), RRR machine (SAE J2788 certified), R-134a and R-1234yf vehicles, refrigerant tracking log forms, service information system (AllData or Mitchell 1), refrigerant-rated gloves, safety goggles
Check: Instructor-observed lab checklist: correct identifier connection, accurate refrigerant ID recorded, machine connected without cross-contamination risk, weight recovered within 5% of system capacity—all steps pass/fail; any unsafe act is an automatic fail requiring repeat.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

A7 – Heating and Air Conditioning
1. Which federal regulation prohibits the intentional venting of automotive refrigerants such as R-134a and R-1234yf?
A7 – Heating and Air Conditioning
2. A refrigerant identifier compliant with SAE J1771 reports R-1234yf at 91% purity. What is the MOST appropriate next action?
A7 – Heating and Air Conditioning
3. What does SAE J2788 require as the minimum recovery efficiency for an RRR machine?
A7 – Heating and Air Conditioning
4. Why must shops maintain separate RRR machines and hose sets for R-134a and R-1234yf?
A7 – Heating and Air Conditioning
5. During hose removal after refrigerant recovery, which sequence minimizes refrigerant release?
ASE EV L3 – Heating and Air Conditioning Systems
6. R-1234yf carries an ASHRAE A2L safety classification. What does this classification indicate?
A7 – Heating and Air Conditioning
7. A technician recovers 1.06 lb from a system with a published capacity of 1.20 lb. Approximately what percentage of the system capacity was recovered?
A7 – Heating and Air Conditioning
8. Which piece of PPE is MOST critical when connecting or disconnecting refrigerant hoses at vehicle service ports?
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