Subcooling Calculator

Calculate and verify subcooling for TXV (thermostatic expansion valve) systems.

Measurements

System Information

Subcooling Formula

Subcooling = Saturation Temp − Liquid Line Temp

Saturation temperature is determined from liquid line (head) pressure using the PT chart for the specific refrigerant.

Target Subcooling Guidelines

RefrigerantTXV TargetPiston Target
R-410A8-12°F5-8°F
R-2210-15°F5-10°F
R-326-10°F4-8°F
  • Low subcooling: Undercharge, restriction, or condenser issue
  • High subcooling: Overcharge, airflow issue, or non-condensables