All installations and services must be performed by qualified service personnel.
Example 3:
Problem: Refrigerant measurements are made on the cooling system of a typical OPB installation. The suction line pressure, measured at the condenser unit, suction line, charging port, is 135 PSIG. The temperature of the refrigerant (R410A) at the evaporator suction line connection is measured as 55°F. What is the degree of superheat for this system?
Solution: Calculate the pressure of the refrigerant at the evaporator suction 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 superheat.
135 | PSIG | (Suction pressure measured at condenser) |
+ 0 | PSIG | (Added for pressure drop of suction line) |
| ||
135 | PSIG | = Estimated pressure of refrigerant at evaporator exit |
From the R410A pressure/temperature chart, at 135 PSIG, the saturation temperature is approximately 47°F
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