Refrigerant Superheat / Subcooling (psig-psia toggle)
Saturation T from bundled P-T tables (R-410A / R-32 / R-454B / R-22 / R-134a); per-input psig vs psia toggle.
Example
You enter
- Refrigerant R_410A
- Suction pressure 130
- Suction unit psig
- Suction line T (°F) 50
- Liquid pressure 350
- Liquid unit psig
- Liquid line T (°F) 100
You get
- Superheat 5.12
- Subcool 6.94
- Superheat flag low
- Subcool flag low
Checked against published worked examples from: ACCA / NATE refrigerant-charging method (project bundled P-T tables).
Details, formula, and sources
Scopein-range / low / high flags.
Formula or tableSaturation T from bundled manufacturer P-T table by linear interpolation. Superheat = T_suction_line − T_sat(P_suction); Subcool = T_sat(P_liquid) − T_liquid_line. Each pressure input has a psig/psia toggle (psig is gauge default; psia adds 14.696 to psig).
Source and editionManufacturer-attributed P-T tables (DuPont, Honeywell Solstice, Chemours Opteon, Arkema Forane) by name; ASHRAE 34 safety classifications by name.
Free accessFree at each manufacturer site; ASHRAE 34 read-only at ashrae.org.
What governsEstimate. AHJ and licensed mechanical contractor govern. ACCA Manual J / D / S supersede rules of thumb.
API field namesrefrigerant, suction_pressure, suction_unit, suction_line_temp_F, liquid_pressure, liquid_unit, liquid_line_temp_F, superheat_F, subcool_F, superheat_flag, subcool_flag
- Standard atmospheric pressure 14.696 psi (psig→psia conversion)NIST
- Superheat target band 8-12 °F (manufacturer typical absent a charging chart)manufacturer commissioning guide typical
- Subcool target band 8-15 °F (manufacturer typical absent a charging chart)manufacturer commissioning guide typical