R-454B Pressure-Temperature Chart
Saturation pressure in psig by temperature for R-454B (Opteon XL41), the A2L refrigerant replacing R-410A in new equipment. R-454B is a zeotropic blend with about 4–5°F of glide, so it has two columns: liquid/bubble for the high side and subcooling, vapor/dew for the low side and superheat. Values are cross-checked against the manufacturer chart and an independent calculation.
R-454B saturation pressure
| Temp (°F) | Liquid / bubble (psig) | Vapor / dew (psig) |
|---|---|---|
| -40°F | 9.5 | 8.5 |
| -30°F | 16.7 | 15.3 |
| -20°F | 24.9 | 23 |
| -10°F | 34.6 | 32.3 |
| 0°F | 46.1 | 43.3 |
| 10°F | 59.5 | 56.1 |
| 20°F | 75 | 70.9 |
| 30°F | 92.9 | 88.1 |
| 40°F | 113.3 | 107.7 |
| 45°F | 124.6 | 118.5 |
| 50°F | 136.6 | 130.1 |
| 55°F | 149.4 | 142.3 |
| 60°F | 162.9 | 155.4 |
| 70°F | 192.5 | 184 |
| 80°F | 225.6 | 216.1 |
| 90°F | 262.5 | 251.9 |
| 100°F | 303.6 | 291.6 |
| 110°F | 348.9 | 336.4 |
| 120°F | 399.1 | 385.8 |
| 130°F | 454.2 | 440.5 |
| 140°F | 514.9 | 501 |
Working with glide
Glide is the practical difference between a single-molecule refrigerant and a blend. R-454B's two components boil at slightly different temperatures, so as it evaporates the temperature drifts up by about 4–5°F even at constant pressure — and the chart splits into a liquid/bubble curve and a vapor/dew curve to capture that. The rule is simple: match the column to the phase you are working with. Suction line and superheat are vapor-side, so use the vapor column; liquid line, subcooling, and total charge are liquid-side, so use the liquid column. On the near-azeotropic R-410A this distinction barely matters; on R-454B it is the difference between a correct and an incorrect superheat reading.
R-454B runs a little lower than R-410A at any given temperature and carries a far lower global-warming potential — see how the four common refrigerants line up on the refrigerant comparison chart. Because it is an A2L, it also brings charge limits and leak-detection requirements.
Common questions
Why does the R-454B chart have two pressure columns?
Because R-454B is a zeotropic blend (R-32 and R-1234yf) with about 4–5°F of temperature glide, so it does not boil or condense at a single pressure. The liquid/bubble column is the pressure where the liquid starts to boil — use it for the high side, liquid-line, subcooling, and total charge. The vapor/dew column is where the last vapor condenses — use it for the low side, suction, and superheat.
Which column do I use for superheat and subcooling?
Use the vapor (dew) column for suction-side work: read the low-side pressure into the vapor column to get the saturation temperature for superheat. Use the liquid (bubble) column for the high side: read the head pressure into the liquid column for the condensing saturation temperature used in subcooling. Mixing them up on a glide refrigerant throws the numbers off by the glide.
What is R-454B replacing?
R-454B (sold as Opteon XL41, Solstice 454B, or Puron Advance) is the primary replacement for R-410A in new residential and light-commercial equipment as R-410A phases down under the AIM Act. It runs slightly lower pressure than R-410A and has a much lower global-warming potential, but it is an A2L (mildly flammable) refrigerant with the handling requirements that come with the class.