R-22 PT Chart and Refrigerant Profile

Where you will find R-22

R-22 (HCFC-22, sold for decades as Freon 22) is in residential and commercial AC and heat pumps built before 2010, and in older commercial refrigeration, chillers and transport units (Arkema). Any split system or condensing unit built in 2010 or later should not have come from the factory charged with R-22.

Check the nameplate first. Systems that read “R-22” may since have been retrofitted with a service blend, so look for a retrofit label on the unit and for added POE oil or a changed expansion device. A system topped off with an unknown blend no longer matches this PT chart. Legacy R-22 cylinders were light green; since 2020 new cylinders are light green-gray (RAL 7044) whatever they hold, so read the label.

R-22 replaced R-12 and R-502 in some applications. It was itself replaced in new equipment by R-410A, which is not a retrofit option for an R-22 system.

Charging R-22

R-22 is a single-component refrigerant: no glide, no fractionation, one saturation temperature per pressure. You can charge it as vapor or liquid. Vapor into the suction side is the safe default with the compressor running; liquid goes in faster but must be metered so it does not reach the compressor as liquid.

• Fixed orifice or piston: most older R-22 split systems use one. Charge to target superheat from CEC Title 24 Table RA3.2-2, valid at 55–115°F outdoor, return dry bulb of 70°F or more and return wet bulb of 76°F or less, with an installer tolerance of ±5°F. The ACCA field approximation, (3 × WB − 80 − DB) ÷ 2, is close but can differ from the table by about 1.5–2°F. Use the target superheat calculator and the superheat calculator.
• TXV: charge by subcooling to the manufacturer target, within ±3°F under Title 24, using the subcooling calculator.

Watch for bad R-22 charts. At least one widely read web chart repeats the 65°F value at 70°F, where the correct figure on this chart is 121.4 psig. Another prints kPa values that are gauge but unlabeled; the CSV here gives kPa absolute.

No new R-22 is being produced, so find and fix leaks before recharging. A leak-free system should not need refrigerant added every season.

Oil and compatibility

R-22 systems run on mineral oil (MO) or alkylbenzene (AB). Copeland lists mineral oil as preferred, a blend of AB and MO with at least 50% AB as an alternate, and POE-32 as a further alternate for R-22 compressors (Copeland AE 93-11). BITZER lists MO and AB.

Oil matters as soon as you leave R-22. HFC blends do not carry mineral oil well, so retrofit guidance varies by blend:

• R-407C needs a complete change to POE (Arkema).
• R-427A is normally run with POE after one oil change (Arkema).
• R-421A is listed by A-Gas as compatible with MO, AB or POE; BITZER lists POE for it and POE or PVE for R-417A.

Replace the filter-drier on any retrofit and follow the blend supplier’s procedure. See the refrigerant oil guide.

Safety, handling and recovery

R-22 is ASHRAE class A1: lower toxicity and no flame propagation. It is also an ozone-depleting substance (ODP 0.055), so knowingly venting it is illegal under Clean Air Act section 608.

Under Section 608 you need Type II (or Universal) certification for split and commercial systems, or Type I for factory-sealed small appliances of 5 lb or less, and only certified technicians may buy it. R-22 is a high-pressure refrigerant under 40 CFR 82.152. Recover appliances under 200 lb to 0 in Hg, and those of 200 lb or more to 10 in Hg. Leak-repair requirements under 40 CFR 82.157 apply to appliances with 50 lb or more.

Recovered R-22 can go back into the same owner’s equipment, but it cannot be sold to a new owner unless an EPA-certified reclaimer has reclaimed it (40 CFR 82.154(d)). Use gray recovery cylinders with yellow tops, and do not mix R-22 with any other refrigerant in one recovery tank.

Status and replacements

The US phase-out came in two steps under 40 CFR 82.15 and the HCFC allowance schedule in 82.16:

• Jan 1 2010: new pre-charged R-22 equipment or components manufactured on or after this date may not be sold, and newly produced R-22 may be used only to service equipment made before 2010.
• Jan 1 2020: production and import ended. Servicing continues only with recovered, recycled, reclaimed or pre-2020 stock.

Some sites give 2015 as the end of US production. That is wrong; the date was Jan 1 2020. From Jan 1 2030, 40 CFR 82.15(g)(6) allows class II substances to be used only if they have been recovered or recycled.

When a system needs more refrigerant than you can justify, the choice is to retrofit with a service blend or replace the equipment. Retrofit options include R-407C, R-438A (MO99), R-422D, R-422B, R-427A, R-417A and R-421A. None is an exact match for R-22. Compare them in R-22 replacement refrigerants, R-22 vs R-407C and R-22 vs MO99, or read the R-22 phase-out guide.

Common questions

Can you still buy R-22?

Yes, if you are Section 608 certified. Only recovered, reclaimed or pre-2020 stock is available, because production and import ended Jan 1 2020.

Is there a drop-in replacement for R-22?

Not an exact one. Every R-22 replacement is a blend with its own pressures and glide, and some need an oil change. Follow the blend maker’s retrofit guide and recheck superheat after the change.

Can you put R-410A in an R-22 system?

No. R-410A needs much higher-rated components and POE oil. See R-22 vs R-410A.