All installations and services must be performed by qualified service personnel.
Now, the degree of superheat can be calculated.
55°F (Suction line temperature at outlet of evaporator)
-47°F (Saturation temperature for R410A at 68 PSIG)
8°F = | Degree of evaporator superheat. |
Example 4:
Problem: Additional refrigerant measurements are made on the cooling system of our typical OPB installation. The liquid line pressure, measured at the condenser unit, liquid line, charging port, is 340 PSIG. The temperature of the refrigerant (R410A) at the evaporator liquid line connection is measured as 95°F. What is the degree of subcooling for this system?
Solution: Calculate the pressure of the refrigerant at the evaporator liquid line connection. With the estimated refrigerant pressure and measured temperature at the same point, tabulated data on R410A from the refrigerant manufacturer, or ASHRAE, can be used to evaluate the degree of subcooling.
340 | PSIG | (Liquid line pressure measured at condenser) |
+ 0 | PSIG | (Added for pressure drop of liquid line) |
| ||
340 | PSIG = | Estimated pressure of refrigerant at evaporator inlet |
From the R410A pressure/temperature chart, at 340 PSIG, the saturation temperature is approximately 105°F
Now, the degree of subcooling can be calculated.
105°F (Saturation temperature for R410A at 340 PSIG)
-95°F (Suction line temperature at outlet of evaporator)
10°F = | Degree of condenser subcooling |
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