R410A Charging Chart
Two methods, one page: charge TXV / EEV systems by subcooling (8–12°F general target, OEM nameplate governs); charge fixed-orifice systems by target superheat. Identify the metering device before choosing a method.
Method 1 — Subcooling (TXV / EEV)
On TXV or EEV systems, the metering device regulates superheat to a fixed setpoint. Superheat tells you the valve is working, not the charge. Charge to a subcooling target read on the liquid line: liquid-line saturation temperature (from discharge PSIG) minus actual liquid-line temperature entering the metering device.
| Condensing temp | PSIG (bubble) |
|---|---|
| 95°F | 296.4 PSIG |
| 100°F | 318.5 PSIG |
| 105°F | 341.9 PSIG |
| 110°F | 366.8 PSIG |
| 115°F | 392.3 PSIG |
| 120°F | 419.4 PSIG |
| 125°F | 447.9 PSIG |
| 130°F | 477.9 PSIG |
Nameplate governs.General 8–12°F target is a starting point — the equipment's OEM charging label supersedes it, and some manufacturers spec a DB-indexed target (e.g. 8°F at 65°F outdoor, 12°F at 105°F outdoor). Never charge past the label spec. HVAC School frames the underlying rule mechanically: on TXV / EEV metering the valve throttles to hold SH near its adjustment setpoint, so SH tells you the valve is working, not the charge — subcooling is the charging indicator, and the OEM's SC target governs what "charged correctly" means for that equipment.
The 95°F outdoor DB reference in the table above is the AHRI Standard 210/240 cooling rating condition, which is why residential AC subcooling targets and OEM charging charts center on the same anchor. If you're charging on a day materially warmer or cooler than 95°F outdoor, the target may shift by DB per the OEM's chart; always cross-check the equipment label for DB-adjusted targets.
Method 2 — Target superheat (fixed-orifice / piston)
On fixed-orifice systems (piston, capillary), the metering device doesn't regulate — charge sets superheat directly. HVAC School's rule is that on fixed-orifice equipment SH IS the charging indicator: add refrigerant, SH falls; remove refrigerant, SH rises. That's why the target-superheat method applies here and only here. Look up target SH by indoor WB and outdoor DB, then match measured SH at the suction line.
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 | 65°F | 75°F | 85°F | 95°F | 105°F | 115°F |
|---|---|---|---|---|---|---|
| 54°F | 8.5 | — | — | — | — | — |
| 58°F | 14.5 | 9.5 | — | — | — | — |
| 62°F | 20.5 | 15.5 | 10.5 | 5.5 | — | — |
| 66°F | 26.5 | 21.5 | 16.5 | 11.5 | 6.5 | — |
| 70°F | 32.5 | 27.5 | 22.5 | 17.5 | 12.5 | 7.5 |
| 74°F | 38.5 | 33.5 | 28.5 | 23.5 | 18.5 | 13.5 |
— = target below 5°F; superheat charging not recommended at these conditions. Industry convention on Trane and Carrier bead charts.
Compact matrix (6 × 6). The full 14 × 13 matrix lives on the R-410A Superheat Chart page.
Weight-based charging — the primary method, SH / SC verifies
Weight is the primary charging method for a new install or a post-recovery recharge. Post-vacuum, charge to nameplate weight with a calibrated scale, then verify by measuring SC (TXV / EEV) or SH (fixed-orifice) at steady state. On residential AC the two should land close to the OEM target if the charge is right — if they don't, something else is going on (measurement error, system fault, or the wrong nameplate). Don't charge to gauge feel or sight glass alone; both are unreliable indicators that routinely land systems overcharged.
Overcharge correction on either method requires refrigerant recovery under EPA Section 608 certification — recover into an evacuated cylinder, don't vent, and don't attempt to "burn off" excess by running the system without cooling load.
Field procedure — either method
- Identify the metering device — inspect the indoor coil label. TXV/EEV → subcooling. Fixed-orifice / piston → superheat.
- Steady-state the system for 10–15 minutes at design or near-design conditions.
- Measure indoor WB (return grille), outdoor DB (shaded, near condenser).
- Read gauges: suction PSIG (low side) and discharge PSIG (high side).
- Read line temperatures: suction line and liquid line, with contact probes on clean, insulated copper 6 inches from the service port.
- Convert pressures to saturation temperatures with the tables above (or the interactive PT calculator).
- Compute measured SH (suction) and SC (liquid). Compare to targets.
- Add or recover in 1–2 oz increments. Re-steady 5 minutes between increments. Iterate until measured matches target within ±2°F.
Brand-specific charging charts
The universal chart above covers the R-410A charging method. Individual OEMs (Carrier, Trane, Lennox, Rheem, Goodman) publish charts with cell values tuned to their equipment. Always use the chart printed on the outdoor unit's access panel for your specific model; the universal chart is for reference, not for final charge decisions on a specific unit.
- Carrier R-410A charging chart — the widely-referenced Carrier service-bulletin chart with the interactive lookup.
- Goodman: Goodman publishes model-specific charging tables in their installation manuals; there is no single "Goodman R-410A chart". Check the sticker inside the outdoor unit access panel.
- Trane: Trane splits by high-efficiency (XV, XR series) and standard-efficiency lines with distinct charts; use the model-specific chart from the installation manual.
- Lennox: Lennox publishes single-chart references in the outdoor unit install manual for their piston-metering lines.
- Rheem / Ruud: Rheem uses OEM-tuned tables in the model-specific service documents.
Related tools
- R-410A Superheat Chart — full 14 × 13 target-superheat matrix + R-410A evap quick table.
- Subcooling Calculator — computes measured SC from liquid-line PSIG and temperature.
- Refrigerant Charge Calculator — weight-based charge for new installs (post-vacuum charge to nameplate weight).
- Carrier R-410A Charging Chart — Carrier-specific bead chart with interactive lookup.
- What pressure should R-410A be? — full residential AC operating envelope.
Frequently asked
›Which R-410A charging method do I use — superheat or subcooling?
Depends on the metering device. Fixed-orifice / piston / capillary tube systems: charge by target superheat (indexed on indoor WB × outdoor DB). TXV / EEV systems: charge by subcooling (typically 8–12°F per the OEM nameplate). Check the indoor coil label — most R-410A systems built after ~2015 are TXV.
›What is the target subcooling for a TXV R-410A residential AC?
General target is 8–12°F liquid-line subcooling under steady-state conditions. The OEM nameplate governs — some manufacturers spec 10°F ±2°F; some spec a range that varies with outdoor DB. Always cross-check against the specific equipment's charging label. Sub-8°F usually indicates undercharge; over-15°F usually indicates overcharge (or a restricted metering device).
›Can I charge an R-410A system without knowing the metering device?
No. The two methods give opposite answers on the same system. On a TXV: measured superheat will hover near the valve setpoint regardless of charge — following the superheat chart tells you nothing useful, and you can walk away from an undercharged system with normal-looking SH readings. On a fixed-orifice: measured subcooling swings wildly with load — the subcooling method gives you unstable readings. Identify the metering device first.
›What R-410A liquid-line pressure should I see on a hot day?
Condenser saturation typically runs 20–30°F above outdoor ambient — so on a 95°F day expect ~115–125°F saturation (419.4 PSIG at 120°F). Subcooling is measured as saturation temperature at the discharge minus the actual liquid-line temperature entering the metering device.
›Does the Carrier bead chart differ from this superheat matrix?
The Carrier chart uses discrete cells (6 WB rows × 6 outdoor DB cols) with rounded target values that generally match the (3×WB − 80 − DB)/2 formula within ±2°F. Manufacturer-tuned adjustments account for coil geometry. See /carrier-410a-charging-chart/ for the Carrier-specific version with the interactive service-bulletin lookup.
›Are Goodman, Trane, Lennox, and Rheem R-410A charging charts different?
Structurally identical: 2D lookup (WB × DB) yielding target superheat for fixed-orifice; single or DB-indexed subcooling target for TXV. Individual cell values differ by ±1–2°F because each OEM tunes to their equipment. Charts are model-specific — always check the sticker inside the outdoor unit's access panel for your specific model. Do not use a Carrier chart on a Rheem unit at the ±2°F precision level; use the OEM chart for your equipment.
›How much refrigerant should I add if I'm below target subcooling?
Add in 1–2 oz increments for residential systems (roughly ¼ oz per pound of installed charge). Wait 5–10 minutes after each addition for the system to re-steady. Measure again. Do not add refrigerant in large increments — you can overshoot and end up recovering. Use a calibrated charging scale, not a sight glass or gauge feel.