9.4 The R-22 Phaseout, Retrofits, and the Move to Lower-GWP A2Ls

Why R-22 Is Disappearing

R-22 (HCFC-22, chlorodifluoromethane) was the dominant air-conditioning refrigerant for decades, but as an HCFC it contains chlorine and depletes the ozone layer (ODP 0.055), so the Montreal Protocol and the Clean Air Act scheduled it out of production. Type II technicians still service millions of legacy R-22 systems, so understanding the phaseout timeline and the retrofit path is essential exam and field knowledge.

R-22 Phaseout Timeline

What "No New Production" Means for Service

Since January 1, 2020, the only legal sources of R-22 are:

• Reclaimed R-22 — recovered refrigerant that a certified reclaimer has reprocessed to AHRI Standard 700 purity (the same purity as virgin refrigerant). Reclaimed R-22 may be resold and used in any owner's equipment.
• Recycled R-22 — refrigerant recovered and cleaned on-site (oil separation, single-pass filtration) for reuse in the same owner's equipment, without reprocessing to AHRI 700.
• Existing stockpiles legally produced or imported before the 2020 ban.

With no new supply entering the market, R-22 prices have climbed sharply, which is the practical reason owners increasingly choose to retrofit or replace rather than keep recharging an aging R-22 system.

Retrofit Options

R-407C: The Most Common R-22 Retrofit

R-407C (a zeotropic blend of R-32/R-125/R-134a) is the standard retrofit for R-22 because its operating pressures are similar to R-22 — but it is not a true "drop-in." Several changes are mandatory:

• Oil change from mineral oil to POE. R-407C is not miscible with mineral oil. The original mineral-oil charge must be removed — often requiring two or three oil changes to get residual mineral oil below ~5%.
• Liquid charging only. R-407C is zeotropic with about 9 degrees F of temperature glide; charging it as vapor would change the blend's composition (fractionation). Charge as liquid, and never top off after a leak — recover and recharge with fresh refrigerant.
• Component service. Replace the filter-drier with one rated for HFC/POE, and check/adjust the TXV because R-407C's pressure-temperature behavior differs from R-22.
• Relabel the equipment to clearly show the new refrigerant and oil type.

Worked Example: A property manager wants a 60-lb R-22 rooftop unit converted to R-407C. The technician (1) recovers all R-22 to the required evacuation level, (2) drains the mineral oil and refills with POE, runs the system, then drains again to flush residual mineral oil below ~5%, (3) installs a new HFC-rated filter-drier, (4) evacuates the system to a deep vacuum (about 500 microns) to remove moisture — important because POE is hygroscopic, (5) liquid-charges R-407C to the manufacturer's weight, (6) verifies superheat and subcooling, and (7) applies a new label. Skipping the oil change or vapor-charging the blend would cause compressor and performance failures.

The Move to Lower-GWP A2Ls

The R-22 story is now repeating one step further down the GWP ladder. Under the AIM Act's Technology Transitions rule, new residential and light commercial AC and heat-pump systems installed on or after January 1, 2025 must use refrigerant with a GWP below 700 (systems whose specified components were all made or imported before that date may still be installed). That cap removes R-410A (GWP 2,088) — itself the HFC that replaced R-22 — from new systems, in favor of mildly flammable A2L refrigerants:

Three practical points for Type II technicians: (1) existing certifications remain valid — no new federal certification is required to service A2Ls; (2) A2L equipment adds safety requirements (charge limits, leak-detection sensors, and spark-source precautions per UL 60335-2-40), and recovery equipment must be rated and listed for A2L service; and (3) existing R-22 and R-410A systems are not outlawed — they may be serviced and recharged for their remaining life, which is why mastery of recovery, leak repair, and retrofit procedures stays essential for years to come.

For the Exam: R-22 production/import ended January 1, 2020 — legacy systems run on recovered, reclaimed, or previously produced R-22. R-407C is not a true drop-in (oil change to POE, liquid charge, TXV/drier service, relabel). New residential and light commercial AC systems have faced a 700 GWP cap since January 1, 2025, driving the shift to A2L R-454B and R-32.