R448A vs R449A: N40 and XP40 Head to Head
Updated October 3, 2026
R-448A (Honeywell Solstice N40) and R-449A (Chemours Opteon XP40) are the two dominant A1 next-generation retrofits for R-404A in medium- and low-temperature commercial refrigeration. Both are HFC/HFO blends with similar GWP (1,386 vs 1,396), similar pressure envelopes, similar temperature glide, POE-compatible lubricant, and A1 safety class. They are peer alternatives — not source-and-target of each other — so the choice between them is driven by manufacturer preference, service supply, and OEM-approval status, rather than a technical retrofit path from one to the other.
- GWP (100-yr)
- 1,386
- Lubricant
- POE
- Glide @ 0°C
- 11.5°F
- GWP (100-yr)
- 1,396
- Lubricant
- POE
- Glide @ 0°C
- 9.5°F
PT curves, overlaid
Solid line = bubble, dashed = dew where the refrigerant has significant temperature glide.
Pressure comparison at service temperatures
Side-by-side pressure values at common service temperatures, computed from CoolProp 7.2.0. Useful for retrofit feasibility — pressure deltas within ±20% typically allow retrofit-compatible service equipment; larger deltas require component pressure-rating review.
| Temperature | R-448A | R-449A | Δ vs R-448A |
|---|---|---|---|
| −20°F | 17 PSIG | 16 PSIG | −3.3% |
| 0°F | 34 PSIG | 33 PSIG | −2.5% |
| 40°F | 89 PSIG | 87 PSIG | −2.2% |
| 70°F | 154 PSIG | 151 PSIG | −1.7% |
| 95°F | 227 PSIG | 223 PSIG | −1.6% |
| 120°F | 321 PSIG | 316 PSIG | −1.4% |
Pressure delta visualization: positive = R-449A runs higher than R-448A; negative = lower. Service equipment pressure rating matters when delta exceeds ±20% on the discharge side. For R-448A (zeotropic blend) bubble pressure is shown; for R-449A same rule applies.
Property differences side by side
- GWP impact: R-448A = 1,386, R-449A = 1,396 (+1% vs R-448A). GWP delta is modest.
- Lubricant: R-448A: POE; R-449A: POE. Same lubricant family — no oil change needed.
Properties side by side
| Property | R-448A | R-449A |
|---|---|---|
| Type | HFC/HFO blend | HFC/HFO blend |
| ASHRAE class | A1 | A1 |
| Composition | 26.0% R-32 / 26.0% R-125 / 20.0% R-1234yf / 21.0% R-134a / 7.0% R-1234ze(E) | 24.3% R-32 / 24.7% R-125 / 25.3% R-1234yf / 25.7% R-134a |
| GWP (100-yr) | 1,386 | 1,396 |
| ODP | 0 | 0 |
| Lubricant | POE | POE |
| Boiling point @ 1 atm | −45.9°C | −45.7°C |
| Critical point | 82.7°C / 654 PSIG | Blend (locus, not point) |
| Temp glide | 11.50°F | 9.51°F |
| AIM Act affected | Yes | Yes |
Choose R-448A if…
Sites and OEMs standardized on the Honeywell supply chain. R-448A is Honeywell's Solstice N40, delivered from Honeywell's manufacturing footprint. The R-448A PT chart is published in the Solstice N40 Technical Data Sheet (Publication 3820, September 2019), and equipment OEMs that have qualified Solstice N40 for their platforms (major commercial refrigeration manufacturers) publish charging procedures against that datasheet.
Choose R-449A if…
Sites and OEMs standardized on the Chemours supply chain. R-449A is Chemours Opteon XP40, delivered from Chemours's manufacturing footprint. OEM approvals and service supply mirror Honeywell's N40 in most markets — the two products compete head-to-head. Chemours publishes XP40 technical data with the same performance envelope and retrofit procedure. Refrigerant reclaim programs for both are established.
When neither is ideal
For sites that want lower GWP than the two 1300-range HFC/HFO A1 blends: R-454C (GWP 146) or R-455A (GWP 146) are the A2L path for low-temperature commercial refrigeration where the A2L safety class + IEC 60335-2-89 compliance is acceptable. For R-404A retrofits in transport refrigeration specifically, R-452A (Opteon XP44 / Solstice L40X) targets that duty cycle with the discharge-temperature advantage documented on our r-404a-vs-r-452a page. For R-404A → next-generation A1 retrofits on stationary MT/LT commercial refrigeration, R-448A and R-449A are the two dominant choices; the decision typically comes down to OEM approval and local reclaim availability.
Retrofit and transition
R-448A and R-449A are peer alternatives for the R-404A → next-generation retrofit path, not source-and-target of each other. There is no service-time retrofit BETWEEN the two — a site converting an R-448A installation to R-449A (or vice versa) would follow the same procedure as any HFC blend change (recover, replace filter-drier, evacuate, recharge). The blends are close enough thermodynamically that equipment sizing and controls don't need adjustment for such a swap, but the reason to switch would be supply-chain rather than technical.
On the retrofit-from-R-404A side, both blends follow the same general procedure. Both use POE lubricant (the R-404A → next-generation switches carry the POE oil forward — no oil-change complication like the R-22 → HFC retrofit family has). Both are A1 safety class, so no safety recertification. Both have zeotropic behavior with roughly 11°F glide, so superheat measurement must use the dew curve at the evaporator outlet. Both drop into R-404A service equipment (compressors, TXVs, filter-driers) without component replacement in the typical case.
The differences that matter for the site-level decision are second-order:
- GWP: nearly identical — R-448A 1386 vs R-449A 1396 (about a 10-point difference). The difference is negligible in either direction. - Composition: R-448A is 26/26/21/7/20 R-32/R-125/R-134a/R-1234ze(E)/R-1234yf (5 components); R-449A is 24.3/24.7/25.7/25.3 R-32/R-125/R-134a/R-1234yf (4 components). The R-1234ze content in R-448A is the compositional distinction. - Manufacturer: R-448A = Honeywell (Solstice N40). R-449A = Chemours (Opteon XP40). Site standardization on one supply chain is often the deciding factor. - OEM approvals: Both are widely approved by major commercial refrigeration OEMs. Individual model families sometimes have one blend qualified before the other; check the equipment's service literature for approved refrigerants before choosing.
For pressure envelope comparison at service temperatures, both blends run within a couple of PSIG of each other across the operating range. At 40°F saturation (a typical medium-temp evaporator), R-448A bubble is approximately 89 PSIG and dew is approximately 72 PSIG; R-449A is 87.4 PSIG bubble and 71.6 PSIG dew (from CoolProp). Roughly 2 PSIG separation on both sides — well within service-envelope tolerance for equipment designed for either blend.
The `not feasible` flag on this page reflects the peer-alternatives framing: there is no service-time retrofit procedure that converts one product to the other, because there is no engineering reason to prefer one over the other on an already-operating system. Both are direction targets from R-404A, not from each other.
Regulatory and transition context
Both refrigerants sit in an active regulatory transition driven by climate-impact rules. The transitions affect availability, pricing, and new-equipment specification.
- AIM Act (40 CFR Part 84): US HFC production / import phase-down. Cap declines from 90% allocation (2022) to 15% by 2036. One or both refrigerants here are AIM Act-affected. US EPA restricts new residential and light-commercial air conditioners and heat pumps using a refrigerant of GWP 700 or more, effective January 1, 2025 (40 CFR 84.54(a)(1)). Limits for other equipment types differ.
- EU: Regulation (EU) No 517/2014, replaced by (EU) 2024/573 (applying from March 11, 2024); 2024/573 uses AR4 GWPs for HFCs and AR6 for other fluorinated gases (recital 8).
- Kigali Amendment to Montreal Protocol (2016): international HFC phase-down framework. The Montreal Protocol has 198 parties; 174 have ratified the Kigali Amendment (as of August 10, 2026). The AIM Act and EU F-Gas are regional implementations. Schedules differ by country group.
- ASHRAE 34-2022: safety classification (A1, A2L, A3, B1, B2L). For A2L refrigerants like R-32, R-454B, R-454C, R-455A: equipment must be A2L-certified, charge limits per IEC 60335-2-40 apply.
Why R-448A → R-449A isn't a direct retrofit
R-448A → R-449A is a full equipment-replacement decision, not a service-time swap. The barriers below are structural — equipment certification, oil chemistry, pressure ratings — so no field checklist can bridge them. The realistic path is to continue servicing existing R-448A equipment through its useful life, then install new R-449A-rated equipment at end-of-life.
- This pair was flagged as non-retrofit in the source data — usually for application-class reasons (mobile AC vs stationary, industrial vs commercial) rather than any single measurable barrier. The refrigerants themselves may be chemically similar, but the equipment classes don't overlap.
Lifecycle and operational context
Beyond the per-service-call decision, the R-448A ↔ R-449A choice sits inside a broader regulatory and lifecycle context. The transition direction (which is the predecessor, which is the successor) is driven by climate policy and the AIM Act phase-down, not technical preference alone.
- GWP profile: R-448A = 1,386 GWP; R-449A = 1,396 GWP. Switching from R-448A to R-449A increases direct refrigerant climate impact by 1%.
- AIM Act exposure: Both refrigerants are subject to the AIM Act phase-down (HFC allocation declining toward 15% of baseline by 2036). One or both have a GWP of 700 or more: US EPA restricts new residential and light-commercial AC and heat pumps at that level, effective January 1, 2025 (40 CFR 84.54(a)(1)). Limits for other equipment types differ.
- EU (Regulation (EU) No 517/2014, replaced by (EU) 2024/573): R-448A (GWP 1,386) meets 2 Annex III placing-on-the-market prohibitions; the earliest is Refrigerators and freezers for commercial use (hermetically sealed equipment) (GWP ≥ 150) from January 1, 2022. R-449A (GWP 1,396) meets 2 Annex III placing-on-the-market prohibitions; the earliest is Refrigerators and freezers for commercial use (hermetically sealed equipment) (GWP ≥ 150) from January 1, 2022.
- Service supply outlook: Service supply of AIM Act-affected refrigerants persists during phase-down via reclaimed and allocated production, with prices rising as supply tightens. Plan for refrigerant cost escalation over equipment lifetime.
- TEWI / LCCP framing: Total Equivalent Warming Impact accounts for both direct refrigerant emissions (leakage, end-of-life) and indirect emissions from equipment energy consumption. For HVAC equipment with ≤5% annual leak rate, indirect emissions typically dominate TEWI by 80-90% — meaning equipment efficiency matters more than refrigerant GWP for total climate impact. For commercial refrigeration with higher leak rates, the balance can tip toward favoring low-GWP refrigerants.
Regulatory sources: AIM Act (40 CFR Part 84), EU F-Gas Regulation 517/2014 and update 2024/573, Kigali Amendment to the Montreal Protocol (2016). GWP values on the US EPA basis (40 CFR 84 / IPCC AR4).
Service implications — R-448A → R-449A
What a service technician needs to know when transitioning from R-448A to R-449A (or comparing them for new equipment specification). Two real-world scenarios show how the difference plays out in practice.
Pressure envelope check for R-448A → R-449A
Scenario · Field tech needs to know: do R-448A service tools handle R-449A, or does the pressure delta require new equipment? PT chart comparison at service temperatures gives the answer.
| Temp | R-448A | R-449A | Δ |
|---|---|---|---|
| 40°F | 89 PSIG | 87 PSIG | −2.2% |
| 70°F | 154 PSIG | 151 PSIG | −1.7% |
| 95°F | 227 PSIG | 223 PSIG | −1.6% |
Service-side implications: lubricant and safety
Scenario · Beyond pressure envelope, the switch from R-448A to R-449A affects lubricant, safety class, and operating procedure.
| Concern | R-448A | R-449A | Action |
|---|---|---|---|
| Lubricant | POE | POE | No change |
| Safety class | A1 | A1 | No change |
| Glide | 11.5°F | 9.5°F | Minor |
When to use which tool for this comparison
- R-448A full reference — properties, PT chart, lubricant, retrofit options for R-448A.
- R-449A full reference — properties, PT chart, lubricant, retrofit options for R-449A.
- PT Comparison Tool — overlay any 2-4 refrigerants' PT curves interactively.
- Retrofit Compatibility Calculator — five-criterion compatibility analysis with verdict.
- Refrigerant Comparison Guide — long-form sourced reference for all common HVAC refrigerant comparisons.
Frequently asked
›Which is better, R-448A or R-449A?
For most stationary medium-temperature and low-temperature commercial refrigeration retrofits from R-404A, either is a valid choice — the two blends are close enough on GWP, pressure envelope, glide, safety class, and lubricant compatibility that the decision usually reduces to (a) OEM approval for the specific equipment model, (b) local reclaim and supply availability, and (c) site-level standardization on the Honeywell or Chemours supply chain. the two are within about 10 GWP points of each other (R-448A 1386 vs R-449A 1396); the difference is small enough to be a tiebreaker rather than a driver.
›Can I switch a system from R-448A to R-449A (or vice versa)?
Yes, but the procedure isn't a 'retrofit' in the R-404A → next-generation sense — it's a same-family blend change. Recover the existing charge, replace the filter-drier (standard practice on any refrigerant change), evacuate to 500 microns, and charge with the new blend to nameplate weight. No oil change (both use POE), no safety recertification (both A1), no equipment component swap. The reason to switch would be supply-chain or OEM approval change, not thermodynamic.
›Do R-448A and R-449A have the same composition?
No — they're peer alternatives from different manufacturers with different compositions. R-448A is R-32/R-125/R-134a/R-1234ze(E)/R-1234yf at 26/26/21/7/20 mass fractions (five components; Honeywell). R-449A is R-32/R-125/R-134a/R-1234yf at 24.3/24.7/25.7/25.3 (four components; Chemours). The R-1234ze content in R-448A is the compositional distinction. Both blends have similar thermodynamic behavior despite the different recipes because R-1234yf and R-1234ze(E) have similar refrigerant properties in these proportions.
›What is the glide for R-448A and R-449A?
Both blends have approximately 11°F temperature glide at 0°C saturation (both are ASHRAE 34 400-series zeotropic blends). Service work must use the dew curve at the evaporator outlet for superheat calculation — using the bubble curve would introduce an error equal to the glide, roughly 11°F. Subcooling on the liquid line uses the bubble curve as usual. The site's calculators handle this automatically.
›Which R-404A retrofit is more common, R-448A or R-449A?
Market share fluctuates by region and time. Both blends have significant install bases in North America and Europe. Some OEMs have historically favored one supplier; site owners often standardize on their equipment OEM's default. In the AIM Act phase-down timeline, both are AIM-Act-affected but sit well below the immediate GWP cutoffs that would drive further phase-down — meaning both remain viable retrofit choices, with the eventual next-step being A2L (R-454C / R-455A) rather than yet another A1 blend.
›Do R-448A and R-449A both use POE oil?
Yes — both are polyol ester (POE) lubricant systems, matching R-404A's POE requirement. The R-404A → R-448A / R-449A retrofit skips the oil change complication that R-22 → HFC blends require. Filter-drier replacement is standard practice for any refrigerant change; check the drier is rated for HFC service and POE-compatible.