Refrigerant retrofit selector
Coming off R-22
| Option | Best for | Oil | Watch out for |
|---|---|---|---|
| R-407C | Closest capacity match to R-22 | Full POE conversion | Zeotropic, moderate glide |
| R-427A | Tolerates residual mineral oil | Minimal oil change | Lower capacity than R-22 |
| R-438A | Tolerates residual mineral oil | Minimal oil change | Contains hydrocarbons for oil return |
| R-407A | Low-temperature duty | Full POE conversion | Higher GWP than R-407C |
The deciding question is the oil. If you can do a full POE conversion, R-407C matches R-22's capacity most closely and is the mainstream answer. If the system makes thorough flushing impractical, a large field-piped installation or one with an oil separator and accumulator, R-427A or R-438A tolerate residual mineral oil and save that work, at some cost in capacity.
R-407C is stocked. R-427A, R-438A and R-407A are not lines we hold, and we would rather say so than take the order. See the R-22 retrofit guide for the detail.
Coming off R-404A
| Option | Best for | Oil | Watch out for |
|---|---|---|---|
| R-448A | Mainstream lower-GWP route | POE, valve adjustment | Higher glide, higher discharge temp |
| R-449A | Comparable to R-448A | POE, valve adjustment | Similar behaviour and GWP |
| R-452A | Transport refrigeration | POE, valve adjustment | Smaller capacity shift |
| R-407F | Low-temperature commercial | POE, valve adjustment | Higher discharge temperature |
The deciding question is discharge temperature. All the lower-GWP replacements run hotter than R-404A, which matters most on low-temperature packs where discharge temperature was already the limiting factor. On medium-temperature duty the change is comfortable.
R-448A is stocked. R-449A, R-452A and R-407F are not lines we hold.
What a retrofit actually involves
Recover the existing charge properly rather than venting it. Change the oil, with repeated flush cycles where a full conversion is needed. Replace the filter drier, every time, because it has been collecting whatever the old system contained. Adjust or replace the expansion device, because the new fluid has different pressure and temperature characteristics. Evacuate deeply. Weigh in the new charge as a liquid. Relabel the equipment so the next technician knows what is in it.
That last one gets skipped constantly and it is the cheapest step on the list. An unlabelled retrofit is a trap for whoever comes next.
When not to retrofit
If the equipment is near end of life, retrofitting spends money on a machine you will replace anyway, and new equipment on a current refrigerant is usually more efficient than an old machine on a retrofit blend.
If the system leaks, fix that first. A retrofit does not stop a leak, and it puts a more expensive charge into a circuit that will lose it.
And if the system is running well on R-22, there is no legal requirement to convert. Servicing existing equipment remains lawful to 2040. The question is commercial: whether the machine will outlive convenient R-22 supply.
Quick answers
What is the best replacement for R-22?
R-407C matches R-22's capacity most closely, but needs a full POE oil conversion. R-427A and R-438A tolerate residual mineral oil, which saves flushing work at some cost in capacity.
Is there a drop-in replacement for R-22?
No. Every route needs at least an oil decision and usually an expansion valve adjustment. The blends marketed as easy retrofits still need the filter drier changed and the charge weighed in.
What replaces R-404A?
R-448A and R-449A are the mainstream lower-GWP routes, with R-452A in transport refrigeration and R-407F for low-temperature commercial duty.
Do I have to retrofit my R-22 system?
No. Servicing existing R-22 equipment remains lawful through registered sellers to 2040. The decision is commercial rather than legal.
- US EPA · SNAP programme listings and retrofit guidance · epa.gov.
- ASHRAE Standard 34 · blend designation and safety classification · ashrae.org.
- Ozone Cell, MoEFCC · HCFC phase-out schedule and servicing tail · ozonecell.nic.in.
This guide is general information compiled from the cited sources — not legal, safety or engineering advice. Read our full disclaimer.
Related: R-22 retrofit options · R-404A retrofit options · Oil compatibility · R-407C supply