R22 Superheat Chart
Target superheat for fixed-orifice R-22 residential AC. Same formula as R-410A; R-22 pressures are substantially lower across the envelope.
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-22 saturation quick table (evaporator range)
R-22 saturation pressures at typical evaporator conditions. Values from CoolProp 7.2.0. R-22 is a pure HCFC — no glide, single curve.
| Saturation temp | PSIG |
|---|---|
| 35°F | 61.5 PSIG |
| 40°F | 68.6 PSIG |
| 45°F | 76.1 PSIG |
| 50°F | 84.1 PSIG |
| 55°F | 92.6 PSIG |
Reading your gauges
On a properly-charged R-22 residential AC at 95°F outdoor with 64°F indoor WB, the evaporator runs around 40°F saturation (68.6 PSIG). The manifold reads slightly higher after superheat pickup on the suction line. Measured suction-line temperature minus 40°F is your measured superheat; match against the 8.5°F target from the matrix.
R-22 saturation pressures are about 60% of R-410A across the envelope — different absolute PSIG values but the same target-superheat math. If you're used to R-410A numbers and switch to an R-22 service call, adjust your gauge-reading habits, not the target.
When target renders as "—"
Cells below 5°F blank because charging by superheat is unreliable at those setpoints. If you land in a blanked cell, verify WB and DB measurements first (dry wick = 2–3°F low; sun on the DB probe = 5–10°F high), then confirm the equipment is fixed-orifice.
Related tools
- Superheat Calculator — measured SH from suction PSIG and line temp.
- R-22 reference page — full PT chart, properties, phase-down context.
- What pressure should R-22 be? — full residential AC operating envelope.
- Target Superheat Chart (universal) — the formula and applicability, refrigerant-independent.
- R-22 vs R-410A comparison — pressure envelope, lubricant, and retrofit differences.
Frequently asked
›What is the target superheat for a fixed-orifice R-22 system?
It depends on indoor wet-bulb and outdoor dry-bulb. Use TSH = ((3 × WB) − 80 − DB) / 2. At the 64°F indoor WB / 95°F outdoor DB design point, target superheat is 8.5°F. Look up other combinations in the interactive matrix above.
›Is the target-superheat formula the same for R-22 and R-410A?
Yes. The formula sets the operating point based on load conditions (WB) and heat rejection (DB); the refrigerant enters only when you convert measured suction pressure to saturation temperature. The R-22 and R-410A charts have the same target values in the same cells — only the PT-chart conversion differs.
›Where do I still find R-22 fixed-orifice equipment in service?
R-22 residential AC production ended in 2010; virgin R-22 production stopped in January 2020 under the EPA HCFC phase-out. Equipment installed 1990–2010 is still widely in service and legal to maintain with reclaimed R-22. Most of that equipment uses fixed-orifice metering (piston or capillary tube), so the target-superheat method still applies during service.
›What is normal R-22 suction pressure at 95°F outdoor?
On a properly-charged R-22 residential AC at the 95°F rating condition, evaporator saturation runs around 40°F (68.6 PSIG). Manifold reads slightly higher due to superheat pickup on the suction line. See /what-pressure-should-r22/ for the full envelope and OEM-observed manifold band.
›Can I use this chart for an R-22 system retrofitted to R-407C or R-422D?
The target-superheat method still applies (retrofit blends don't change the fixed-orifice charging approach), but the suction-pressure to saturation-temperature conversion uses the retrofit refrigerant's PT curve. R-407C is zeotropic with ~11°F glide — use the dew curve at the evaporator outlet. R-422D is a near-azeotrope — single curve is adequate.
›Reclaimed R-22 is expensive. Is it worth troubleshooting to superheat target rather than just swapping the system?
Depends on remaining equipment life and reclaim cost in your market. Reclaimed R-22 typically runs $50–150/lb (2024–2026 residential service market). A residential AC with a ~4 lb charge and 5+ years of expected life is worth diagnosing and correcting to target. A 20+ year-old system with a leaking coil is often better replaced with new equipment; superheat-charge the new one instead.