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TheBlueprintof Water

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Operating Case

Enter your system parameters. Results update automatically.

ChooseEnter the tower by its condenser water flow, or by its tonnage. 3 gpm per ton is the standard design flow.
Condenser water flow. If you only know tons, 3 gpm per ton is the standard design flow.
gpm

If Tonnage is selected, recirculating flow will be calculated at 3 gpm per ton (standard design).

Supply & Return TemperatureReturn minus supply is the temperature range across the tower, the ΔT the evaporation formula uses.
°F
°F
Calculated ΔT (Return minus Supply)10 °F
Total water in the tower, the basin, and the connected piping. Needed only for the chemistry half-life.
gal

Total water volume in tower, basin, and connected piping. Affects chemical turnover (half-life).

Water carried out as droplets in the air stream. Modern eliminators hold 0.001 to 0.005%, guaranteed as low as 0.0005%; older towers and worn eliminators run 0.02 to 0.2%.
%

0.005% is a modern tower. Older eliminators run 0.02 to 0.2%.

Fraction of heat rejected by evaporation, folded into the 0.001 factor: E = R × ΔT × 0.001 × latent fraction (about 0.8 typical, up to 1.0 in very dry, hot conditions, lower in cold weather).

Fraction of heat rejected through evaporation. Typical design value (0.8 to 0.9). Editable.

Equivalent full-load hours as a share of the 8,760 hours in a year. Used for the annual water use and cost.
%

Percentage of time the system operates at full load. Used to calculate annual water use and cost.

Common Annual Load RangesStandard office buildings: 15 to 20%Hospitals: 40 to 60%Manufacturing: 50 to 70%Campus central plants: 30 to 50%
The ratio of basin to makeup conductivity (or chloride). Blowdown is computed from it, not measured.
×

Main operating lever. Changes update water balance instantly.

Click on any stream to learn more.

Cooling Tower Water Balance

All flow rates are live and update with your inputs.

Operating Conditions
Recirculation
1,500 gpm
Supply Temperature
85 °F
Return Temperature
95 °F
Temperature Delta
10 °F
Cycles of Concentration
4.0 ×

Key Results

Primary outputs and operational context based on your inputs.

Values based on gpm. Annual values estimated using 15% EFLH. Daily values assume 24 hr/day full-load operation during peak season.

Makeup Water Fresh water in. Replaces evaporation, drift, and blowdown.

17.00 gpm

1.34 M gal/yr

Replaces evaporation + drift + blowdown.

Evaporation Water leaving as vapor. It carries the heat and leaves every mineral behind.

12.75 gpm

1.01 M gal/yr

Heat rejected through evaporation (≈ 85% of total).

Drift Water leaving as droplets, at basin concentration, so it removes solids the way blowdown does.

0.08 gpm

5.9 k gal/yr

Water lost as fine droplets (≈ 0.005% of recirculation).

Blowdown The bleed to the drain that holds the cycles. The one loss you control.

4.18 gpm

329.2 k gal/yr

Controls dissolved-solids removal and strongly influences chemical usage.

Chemistry Half-Life How long a slug-fed chemical takes to fall to half its concentration, from blowdown and drift alone: 0.693 × V ÷ ((B + D) × 60).

40.8 hours

Determined by system volume and blowdown rate.

Water + Sewer Cost Combined water and sewer rate per thousand gallons of makeup.
$
per 1,000 gal
Estimated Annual Cost$8,042

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