During charging in cooling mode, if the suction pressure is 153 psig and the liquid pressure is 410 psig, what should be the correct pipe temperature for ten degree subcooling?

To determine the correct pipe temperature during charging in cooling mode with the given subcooling requirement, we need to understand the relationship between pressure and temperature in refrigerants.

In a cooling mode, when subcooling is applied, it indicates that the liquid refrigerant is cooled down further below its saturation temperature before entering the expansion device. The pressure of the refrigerant often correlates directly with its saturation temperature. For instance, if the liquid pressure is at 410 psig, the corresponding saturation temperature can be obtained from refrigerant tables or pressure-temperature relationship charts.

After identifying the saturation temperature at 410 psig, subtracting the desired subcooling amount (10 degrees) from that saturation temperature will provide the correct temperature of the refrigerant in the liquid line before it enters the metering device.

If the saturation temperature corresponding to the 410 psig pressure is calculated (which typically would be around 118 degrees Fahrenheit), and then subtracting the 10-degree subcooling, will yield a pipe temperature of approximately 108 degrees Fahrenheit.

This method highlights the importance of understanding pressure-temperature relationships within refrigeration cycles, especially when accounting for system efficiencies and proper refrigerant behavior. Therefore, the calculated pipe temperature of 108 degrees for ten-degree