A properly sized chiller will properly cool process equipment. Here is an equation to calculate the load requirements:
BTU = Constant x GPM x Temperature Differential
| 500 | constant (weight of water) | |
| x 10 | GPM (gallons per minute) | |
| x 12 | degrees Temperature Differential (or rise) | |
| _______ | _________________________________ | |
| 60,000 | Required BTUs per hour |
In the above example, the process equipment, being cooled 12 degrees by pure water at 10 GPM, would require a 5 ton chiller since 12,000 BTUs = 1 ton of cooling.