What is the required method for calculating sub cooling with R-407C?

Subcooling in the context of refrigerants, like R-407C, refers to the process of cooling refrigerant below its condensing temperature. To accurately calculate subcooling, using the bubble point value is essential.

The bubble point represents the temperature at which a refrigerant transitions from a liquid to a vapor at a given pressure. In the context of R-407C, utilizing the bubble point allows for determining the temperature at which the refrigerant starts to evaporate at the respective pressure. By knowing the actual temperature of the refrigerant in the liquid state, you can effectively find the degree of subcooling. Subcooling can then be calculated by subtracting the bubble point temperature from the actual liquid temperature.

Using other methods such as dew point values or evaporating pressures would not yield an accurate representation for subcooling calculations because they are relevant to different phases of the refrigerant's state. The absolute temperature does not directly relate to the phase transitions necessary to determine subcooling, making the bubble point the most relevant measurement for this calculation. Therefore, the correct approach to calculating subcooling with R-407C is indeed to use a bubble point value.