R410A Superheat Chart
Target superheat for fixed-orifice R-410A residential AC. Look up target by indoor WB × outdoor DB, then match against measured superheat at the suction line.
Interactive lookup and matrix
Measured at the return-air grille with a wet-wick psychrometer. Typical cooling: 60–72°F WB.
Shaded thermometer near the condenser. Design condition: 95°F.
| WB \ DB | 55°F | 60°F | 65°F | 70°F | 75°F | 80°F | 85°F | 90°F | 95°F | 100°F | 105°F | 110°F | 115°F |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 50°F | 7.5 | 5.0 | — | — | — | — | — | — | — | — | — | — | — |
| 52°F | 10.5 | 8.0 | 5.5 | — | — | — | — | — | — | — | — | — | — |
| 54°F | 13.5 | 11.0 | 8.5 | 6.0 | — | — | — | — | — | — | — | — | — |
| 56°F | 16.5 | 14.0 | 11.5 | 9.0 | 6.5 | — | — | — | — | — | — | — | — |
| 58°F | 19.5 | 17.0 | 14.5 | 12.0 | 9.5 | 7.0 | — | — | — | — | — | — | — |
| 60°F | 22.5 | 20.0 | 17.5 | 15.0 | 12.5 | 10.0 | 7.5 | 5.0 | — | — | — | — | — |
| 62°F | 25.5 | 23.0 | 20.5 | 18.0 | 15.5 | 13.0 | 10.5 | 8.0 | 5.5 | — | — | — | — |
| 64°F | 28.5 | 26.0 | 23.5 | 21.0 | 18.5 | 16.0 | 13.5 | 11.0 | 8.5 | 6.0 | — | — | — |
| 66°F | 31.5 | 29.0 | 26.5 | 24.0 | 21.5 | 19.0 | 16.5 | 14.0 | 11.5 | 9.0 | 6.5 | — | — |
| 68°F | 34.5 | 32.0 | 29.5 | 27.0 | 24.5 | 22.0 | 19.5 | 17.0 | 14.5 | 12.0 | 9.5 | 7.0 | — |
| 70°F | 37.5 | 35.0 | 32.5 | 30.0 | 27.5 | 25.0 | 22.5 | 20.0 | 17.5 | 15.0 | 12.5 | 10.0 | 7.5 |
| 72°F | 40.5 | 38.0 | 35.5 | 33.0 | 30.5 | 28.0 | 25.5 | 23.0 | 20.5 | 18.0 | 15.5 | 13.0 | 10.5 |
| 74°F | 43.5 | 41.0 | 38.5 | 36.0 | 33.5 | 31.0 | 28.5 | 26.0 | 23.5 | 21.0 | 18.5 | 16.0 | 13.5 |
| 76°F | 46.5 | 44.0 | 41.5 | 39.0 | 36.5 | 34.0 | 31.5 | 29.0 | 26.5 | 24.0 | 21.5 | 19.0 | 16.5 |
— = target below 5°F; superheat charging not recommended at these conditions. Industry convention on Trane and Carrier bead charts.
R-410A saturation quick table (evaporator range)
Convert suction pressure to evaporator saturation temperature (or vice versa) at typical AC evap conditions. Values from CoolProp 7.2.0.
| Saturation temp | PSIG (bubble) |
|---|---|
| 35°F | 107.7 PSIG |
| 40°F | 118.8 PSIG |
| 45°F | 130.6 PSIG |
| 50°F | 143.2 PSIG |
| 55°F | 156.5 PSIG |
Reading your gauges
On a properly-charged R-410A residential AC at the 95°F rating condition with 64°F indoor WB, the evaporator runs around 40°F saturation (118.8 PSIG). The manifold at the low-side service port reads slightly higher than this due to superheat pickup on the suction line between the coil and the port. Measured suction-line temperature minus 40°F is your measured superheat; match against the 8.5°F target from the matrix.
At a warmer 105°F outdoor day the condenser saturation climbs into the 115–120°F range (419.4PSIG), the evaporator can hold at ~40°F saturation with adequate airflow, and the target superheat drops (target at 64°F WB / 105°F DB = 3.5°F — see the "—" footnote if the matrix blanks a cell). Charge decisions still follow the same procedure; the SH target just shifts.
When target renders as "—"
Cells below 5°F blank out because charging by superheat becomes unreliable there — normal probe error swamps the target. If your operating point falls in a blanked cell, verify the measurements first (dry psychrometer wick, sun-shaded DB probe), then check that the system is actually fixed-orifice. Many modern R-410A residential AC units built after 2015 are TXV and should be charged by subcooling instead.
Related tools
- Superheat Calculator — measured SH from suction PSIG and line temp for R-410A and any other refrigerant.
- R-410A reference page — full PT chart, properties, GWP, lubricant, retrofit context.
- What pressure should R-410A be? — full residential AC operating envelope with head + suction ranges.
- R410A Charging Chart — two-method charging: TXV/EEV by subcooling, fixed-orifice by superheat.
- Target Superheat Chart (universal) — the underlying formula and applicability, refrigerant-independent.
Frequently asked
›What is the target superheat for a fixed-orifice R-410A system?
It depends on indoor wet-bulb and outdoor dry-bulb. Use the formula TSH = ((3 × WB) − 80 − DB) / 2. At the design point of 64°F indoor WB and 95°F outdoor DB, target superheat is 8.5°F. Look up other combinations in the interactive matrix above.
›How do I read R-410A suction pressure at the evaporator?
Connect the manifold to the low-side service port and read pressure in PSIG after 10–15 minutes of steady operation. Convert to evaporator saturation temperature using the R-410A quick table on this page (or the interactive PT calculator). The saturation temp is what the coil is boiling at; the suction-line temp minus that is superheat.
›Does R-410A have temperature glide that affects superheat measurement?
R-410A is a near-azeotrope with ~0.7°F glide — small enough that most techs treat it as a single-curve fluid for service purposes. The bubble and dew saturation curves are essentially the same. This differs from R-407C or R-454C, where the ~11°F and ~29°F glide requires using the dew curve at the evaporator outlet.
›Should I use this chart if my R-410A system has a TXV?
No. TXV systems regulate superheat to a fixed setpoint (typically 8–15°F) regardless of ambient. Superheat on a TXV system tells you the valve is working — it does not tell you the charge state. Charge TXV / EEV R-410A systems by subcooling (typically 8–12°F per the OEM nameplate). See the R-410A Charging Chart for the subcooling method.
›What is normal R-410A suction pressure at 95°F outdoor?
On a properly-charged residential R-410A system at the 95°F rating condition, the evaporator runs around 40°F saturation (118.8 PSIG). Actual manifold suction reads slightly higher after superheat pickup on the line between the coil and the service port. See /what-pressure-should-410a/ for the full operating envelope with the OEM-observed manifold band.
›The measured superheat is far from the target — what do I do?
First verify measurement: WB, DB, suction pressure, and line-temp probe placement. Then add or recover in small increments (1–2 oz at a time on residential systems), giving 5 minutes between adjustments to re-steady. Persistently high SH with low subcooling = undercharge. Persistently low SH with high SC = overcharge. Neither pattern matches = check indoor airflow and metering-device installation before touching charge.