R-22 vs R-32

What changes in the field

R-32 runs much higher than R-22. From the PT data, at 40°F evaporating R-22 reads 68.6 psig and R-32 121.0 psig, 52.4 psi more. At 100°F condensing R-22 is 195.9 psig and R-32 325.7 psig, 129.8 psi more. Both are single-component refrigerants with no glide, so each has one PT column.

The pressure difference crosses a Section 608 line. At 104°F R-22 saturates at 222.4 psia (high pressure) and R-32 at 359.4 psia, just over the 355 psia cutoff, so R-32 equipment is very high pressure under 40 CFR 82.152. Type II or Universal certification covers both. Recovery for equipment under 200 lb goes to 0 in Hg either way.

R-22 is A1. R-32 is A2L, which means a recovery machine certified for flammable refrigerants under Appendix B4 of 40 CFR 82.158, gauges and hoses rated for R-32 pressures, and the cylinder with a red band. Many A2L cylinders use left-hand thread valves, so an R-22 adapter set may not fit. Keep the two refrigerants in separate recovery cylinders. See recovery machine compatibility.

Oil is not compatible either. R-22 systems run mineral oil or alkylbenzene; Copeland’s approved-lubricant bulletin lists POE for R-32 compressors. The oil types guide explains why HFCs need POE.

Retrofit or replacement

You cannot convert an R-22 system to R-32:

1. EPA’s SNAP listing for R-32 in residential and light commercial AC and heat pumps is for new equipment only, under use conditions based on UL 60335-2-40 (86 FR 24444). An R-22 system was never evaluated for a flammable refrigerant.
2. The R-22 compressor, coils and components were designed for about 196 psig condensing at 100°F, not about 326 psig.
3. The mineral oil is the wrong lubricant.

That leaves two paths. Repair the R-22 system with R-22, which remains legal using recovered, recycled, reclaimed or pre-2020 stock (production and import ended Jan 1 2020), or convert it to a listed R-22 retrofit blend after recovering all the R-22; see R-22 replacement refrigerants. Never add any other refrigerant to the R-22 left in a system.

Or replace the equipment with a new R-32 system and follow its installation manual on whether an existing line set can stay; this page has no manufacturer source on reusing R-22 line sets with R-32. New R-32 equipment is allowed under 40 CFR 84.54, since its AR4 GWP of 675 is under the 700 limit for new residential and light commercial AC and heat pumps. The R-22 phase-out page has the dates.

Capacity, efficiency and cost

None of the sources used here compares R-32 and R-22 systems directly, so no capacity or efficiency percentage is quoted. Arkema’s R-32 material compares it with R-410A, not R-22, and states that a typical R-32 charge is about 30% less than R-410A. A new R-32 system’s performance is in its AHRI rating, which reflects the whole matched system, not just the refrigerant.

On cost, R-22 is now a finite supply: recovered refrigerant cannot be sold to a new owner unless an EPA-certified reclaimer has reclaimed it. R-32 is in production but, as an HFC, its supply falls under the AIM Act phasedown, which caps allowances at 60% of baseline in 2024–2028 and 30% in 2029–2033. R-22 has an ODP of 0.055 and an AR4 GWP of 1,810.

Common questions

Which cools better, R-22 or R-32?

The refrigerant alone does not decide it. A new R-32 system is designed around R-32 and rated as a system; an old R-22 system is limited by its age and condition. Compare AHRI ratings, not refrigerants.

Can I use my R-22 gauges on R-32?

Only if they are rated for R-32 pressures and your tools are listed for A2L use, with R-32 in the PT data. Check the gauge’s rated range against the R-32 condensing pressures in the table above.