An overall check for water-cooled condenser performance may be used after, AND ONLY AFTER, the condenser has been properly purged. After the condition of the condensing surface has been determined, prepare the system as outlined in the procedure used to check for noncondensable gases discussed earlier in the chapter. Then proceed as follows:

1. While the compressor is in operation, record the condensing temperature which corresponds to the pressure in the condenser.

2. Record the temperature of the water leaving the condenser.

3. Subtract the temperature of the water leaving the condenser from the condensing temperature. (The temperature of the water leaving the condenser should be several degrees below the condensing temperature of pure R-12.)

4. If the difference between the temperature of the water leaving the condenser and the condensing temperature is 5 to 10F above the temperature difference obtained when the con-denser was in good condition and operating under similar heat loads, and if this difference is not caused by an overcharge of refrigerant or non-condensable gases, clean the water side of the condenser.