Cooling Tower Make-up Water Flow Rate CalculationCooling Tower Make-up Water Flow Rate CalculationCooling Tower Make-up Water Flow Rate CalculationCooling Tower Make-up Water Flow Rate Calculation

To calculate the make-up water flow rate, determine the evaporation rate using one of the

following:

1. The evaporation rate is approximately 2 GPM per 1 million BTU/Hr of heat

rejection.

2. The evaporation rate is approximately 3 GPM per 100 tons of

refrigeration.

3. Evaporation Rate (GPM) = Water Flow Rate (GPM) x Range (°F) x 0.001.

Multiply the evaporation rate by the appropriate correction factor in the table below to

calculate the make-up water flow rate, in GPM.

Cycles ofConcentration

Correction Factor

2 2.003 1.504 1.335 1.256 1.207 1.178 1.149 1.1310 1.11

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