How to Enter Data into the Calculator
The only cells that can be changed are the ones with a gray background.
Under the Current Program tab,
- Enter Tons of Cooling in the Current Program box. The recirculation rate will automatically fill in.
- Enter the Average Load on the tower over the days in which it is in operation. Enter the load as a decimal. For example 50% = 0.5
- Enter the current Delta T across Tower
- Enter the current Cycles of Concentration
- Enter the Days of Operation per Year
- Enter the Cost of Water and Sewer Charges per thousand gallons.
At this point the the volumes and costs of evaporation, bleed and makeup will be displayed in the yellow boxes.
- Enter the target Cycles of Concentration in the box under the Proposed Program tab.
- Review the summary of cost savings under the Cost Savings Summary tab.
On the Cost Savings Summary tab you can find a "Print" button to print out a hard copy of the form.
The reductions in bleed and makeup will be calculated, together with the potential cost savings.
- This calculator is set up using standard cooling tower calculations and rules-of-thumb.
- The standard rule of thumb is that the recirculataion rate is three times the tonnage of the tower. Newer reciprocating chillers may have a recirculation rate that is less. They will also have nameplates on the pump frame that show the the pump rating. In this case, adjust the tons of cooling to reflect the actual recirculation rate for the chiller.
- If this is not a comfort cooling application, obtain the recirculation rate from the pump nameplate and divide by three. Use this number for the tons of cooling.
- If the makeup water is metered and recorded or there is some other way to determine the actual tower makeup (such as water bills), adjust the so that the calculated makeup is the same as the actual makeup.
- If bleed is also metered, divide actual makeup by actual bleed to obtain obtain cycles of concentration. Adjust load so that calculated volumes agree with actual volumes.
- Sewer Diversion - Some but not all sewer districts will give credit for evaporation. Many customers are not aware of this. The savings that are shown are for the maximum credit. Sewer diversion may also be available for metered irrigation. Add credibility by making sure that our client obtains the maximum available credits.