Why these two numbers matter
Superheat is how much hotter the suction gas is than the evaporating temperature. Too little superheat can send liquid to the compressor. Too much means the evaporator is starved. Subcooling is how much cooler the liquid is than the condensing temperature. Some subcooling means a solid liquid feed to the expansion valve.
How this calculator works
Superheat = Suction line temperature − Evaporator saturation temperature. Subcooling = Condenser saturation temperature − Liquid line temperature. Read saturation temperatures from the refrigerant P–T chart at the measured pressures. Typical targets depend on the plant; many provision systems run about 5–10 K superheat. Follow the maker’s values.
Who should use it
Useful for engineers checking a reefer or AC plant. Recovered refrigerant handling must follow MARPOL and company rules.