Water Make-Up Requirements of Cooling Towers

Evaporative cooling towers, like the ADVANTAGE Power Tower® Series, provide cooling by evaporating a small amount of the recirculated process water flow.

Approximately 1,000 BTU’s are required to evaporate .12 gallons of water. Therefore, every tower ton (15,000 BTU/hr) requires approximately 1.8 gallons of water evaporation, or .03 gpm/ton.
As water evaporates in a cooling tower system, the water vapor enters the atmosphere while any dissolved solids remain behind, building concentration in the remaining water.
Most water treatment systems control this concentration by bleeding off the high concentration water, which is made up by fresh city water with a lower solid concentration. The amount of water that is bled off by the water treatment system is usually less than or equal to the amount of water that evaporates.
Therefore, the maximum normal water makeup for a cooling tower system is .06 gpm / ton, or about 2% of the nominal tower flow rate.
The following chart specifies the Maximun Water Make Up requirement per model.

Advantage Power Tower

Model shown: TC-135G3

The following chart specifies the Maximun Water Make Up requirement per model.

TC-45F @ 45 tons

Maximum Evaporation

1.35 GPM

at designed capacity

Nominal Tower Flow Rate

135 GPM

Maximum Water Make-Up

2.7 GPM

at designed capacity

TC-85F @ 85 tons

Maximum Evaporation

2.55 GPM

at designed capacity

Nominal Tower Flow Rate

255 GPM

Maximum Water Make-Up

5.1 GPM

at designed capacity

TC-105F @ 105 tons

Maximum Evaporation

3.15 GPM

at designed capacity

Nominal Tower Flow Rate

255 GPM

Maximum Water Make-Up

6.3 GPM

at designed capacity

TC-135F @ 135 tons

Maximum Evaporation

4.05 GPM

at designed capacity

Nominal Tower Flow Rate

405 GPM

Maximum Water Make-Up

8.1 GPM

at designed capacity

TC-170F @ 170 tons

Maximum Evaporation

5.10 GPM

at designed capacity

Nominal Tower Flow Rate

510 GPM

Maximum Water Make-Up

10.2 GPM

at designed capacity

TC-210F @ 210 tons

Maximum Evaporation

6.30 GPM

at designed capacity

Nominal Tower Flow Rate

630 GPM

Maximum Water Make-Up

12.6 GPM

at designed capacity

TC-270F @ 270 tons

Maximum Evaporation

8.10 GPM

at designed capacity

Nominal Tower Flow Rate

810 GPM

Maximum Water Make-Up

16.2 GPM

at designed capacity

TC-405F @ 405 tons

Maximum Evaporation

12.15 GPM

at designed capacity

Nominal Tower Flow Rate

1,215 GPM

Maximum Water Make-Up

24.5 GPM

at designed capacity

TC-540F @ 540 tons

Maximum Evaporation

16.20 GPM

at designed capacity

Nominal Tower Flow Rate

1,620 GPM

Maximum Water Make-Up

32.4 GPM

at designed capacity

For more information about water make-up requirements and cooling tower systems call the Advantage Sales Department at 317-887-0729.

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