Refrigerants
Refrigerant types, pressure-temperature charts, superheat and subcooling, and how charge is verified.
Calculators
Refrigerant PT Charts: R-410A, R-32 and R-22 Pressure-Temperature TablesA PT chart gives the saturation temperature for each pressure of a refrigerant. At 40 °F, R-410A sits near 118 psig, R-3…Superheat and Subcooling Calculator: Formulas, Targets and ReadingsSuperheat is the suction line temperature minus the evaporator saturation temperature. Subcooling is the condensing satu…
Guides
AC Refrigerant Charge: How Technicians Verify the Right AmountAn air conditioner's charge is verified, not guessed. Systems with a fixed metering device are checked by superheat, sys…AC Refrigerant Types: R-22, R-410A, R-32 and R-454B ComparedMost US home systems use R-410A, older ones R-22, and new equipment built from 2025 uses lower-GWP A2L refrigerants, mai…