hvac calculator
Superheat & Subcooling Calculator
Compute refrigerant superheat and subcooling from measured line temperatures and the saturation temperatures off your P-T chart.
How it works
Superheat = suction line temp - saturation temp at suction pressure. Subcooling = saturation temp at liquid pressure - liquid line temp.
Worked example
Suction line 55 F, saturation 40 F: superheat = 55 - 40 = 15 F.
When to use it
- Read the saturation temperatures from your refrigerant's P-T chart at the measured pressures.
- Charge to the equipment manufacturer's target superheat and subcooling.
- Fill just the suction pair, just the liquid pair, or both.
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All results are an engineering estimate — not for custody transfer. Field measurement and certified tables govern.