Saturation, superheat, and subcooling. Tables are field-typical — OEM PT and nameplate still win. How to charge R-32 · Weigh-in
High pressure. Use 400+ psig rated gauges, hoses, and recovery. Being phased toward A2L replacements.
Suction pressure → sat. Suction line temp − sat = SH.
Liquid pressure → sat. Sat − liquid line temp = SC.
Temperature in, saturation pressure out.
Pressure
129.8 psig
| °F | psig | °F | psig |
|---|---|---|---|
| -40 | 10.9 | 60 | 169.6 |
| -30 | 17.9 | 65 | 184.6 |
| -20 | 26.4 | 70 | 200.4 |
| -10 | 36.5 | 75 | 217.1 |
| 0 | 48.4 | 80 | 234.9 |
| 5 | 55.0 | 85 | 253.6 |
| 10 | 62.3 | 90 | 273.4 |
| 15 | 70.0 | 95 | 294.3 |
| 20 | 78.3 | 100 | 316.3 |
| 25 | 87.3 | 105 | 339.5 |
| 30 | 96.8 | 110 | 363.9 |
| 35 | 107.1 | 115 | 389.6 |
| 40 | 118.1 | 120 | 416.6 |
| 45 | 129.8 | 125 | 444.9 |
| 50 | 142.2 | 130 | 474.6 |
| 55 | 155.5 |
Use OEM superheat chart. Low SH = overcharge or low load. High SH = undercharge or restriction.
Charge by subcooling. SH is a TXV health check, not a charge knob.
Confirm reversing valve is in cool. Outdoor is condenser.
Outdoor is evaporator. Frost can be normal. Check defrost separately.