Although the refrigerant is R–22, the condensing temperature is not the same as the ARI standard of 105°F which means that the Standard catalog can not be used to make your selection. In this case, you can call your local representative or one of Standard’s sales engineers for a computer generated selection. In this case, a SST–200A (4 Pass) will perform with 7.27 gpm and a pressure drop of 1.75 psi. The 62,300 Btu load would normally require a 5 hp (SST–500A) at the usual ARI rating point of 85°F, 105°F condensing, and R–22. The SST–500A would work in this application although it is three times larger than necessary.

You should always compare performance data when your application conditions vary from normal operating conditions, in order to arrive at the best match for your application.

Other Considerations

Remember to consider all of the factors that affect performance; not just flow rates, TD, fouling, pressure drop, and types of fluid, but also the pull–down factor and pumpdown capacity. Higher loads under pull–down conditions call for an additional ten percent capacity if a very short pull–down time is required, or if slight increases in head pressure or water flow are unacceptable. In a 66,000 Btu system, you must add an additional 6,600 Btu for a total condenser sizing requirement of 72,600 Btu. Pumpdown requirements relate to the amount of refrigerant storage available in a condenser during operation or servicing. A pumpdown capacity of three pounds of refrigerant per ton of capacity will be sufficient for most systems. However, commercial refrigeration systems may require up to seven pounds per ton because of long refrigerant lines. Standard rates its condenser pumpdown capacities at 80% of volume.

In addition to selection tables, you can also utilize Standard’s computerized selection service. Just complete the information in our heat exchanger specification form and mail or fax it to our sales engineering department, or sales representative’s office.

Standard Refrigeration is always happy to build customized condensers if an application calls for a modified condenser with additional valves, water or refrigerant fittings, special mounting brackets, or other accessories.