Selection

Selecting the proper subcooler for your application depends on the following basic sizing considerations.

Range

The temperature difference of the liquid refrigerant being subcooled, entering, and leaving the subcooler.

Approach

Difference between the subcooled liquid leaving the subcooler, and the suction temperature of your dx system.

Capacity

The number of tons of refrigeration required to subcool the liquid refrigerant of the lower temperature system. Select the proper capacity chart identified for your particular range. At the top of the table various approach temperatures are given. Find the approach desired and read down the tons column until you reach the capacity adequate to do the job. The subcooled refrigerant pressure drop (in psi) is listed next to the capacity figure. To determine refrigerant lbs/Min multiply tons by the factor noted below each range chart.
Load Factor table provides a multiplier to your lower temperature system in tons to determine the required capacity of a subcooler. For example, a low temperature system with 18 tons of capacity @ -20°F. evaporating temperature would use the multiplier .18 for a R-22 50° range. The required capacity of the subcooler would be:

18 tons x .18 = 3.24 tons

Load Factors to 50°F.

Limitations

1. Minimum incoming suction temperature of 10°F.
2. Maximum incoming refrigeration liquid temperature of 130°F.
3. Do not use solenoid valves to control liquid temperature. We recommend modulating controls only as opposed to on/off controls. This will tend to avoid pressure pulsation and large temperature excursions.
4. It is strongly recommended that the same refrigerant be used on both sides of the subcooler.Failure of tubes caused by vibration or pulsation may result in cross contamination of refrigerants, even though leakage to the atmosphere has not occurred. Use of like refrigerants will eliminate that potential liability. Standard's warranty does not include payment for refrigerant.