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Excel tool

Cooling Tower Thermal Rating and Upgrade

Know what your tower will do next summer, and which upgrade actually pays.

Predict cold water for any weather, flow, load or fan condition — and compare fill, fan and extra-cell upgrades with payback.

USD 49

FormatExcel workbook (.xlsx), no macros
Versionv1.0
Works inExcel 2010 or later, Windows and Mac
UnitsSI, US and British, mixed freely
IncludesGuide tab with method and references, calculator, print-ready report
Free versionTry the online calculator

Single-user licence. Team and site licences: see options. Instant download after payment; you also get updates to this major version.

Cooling Tower Thermal Rating and Upgrade — sample pages
Cold water against wet-bulb for the example tower (PlantCalcKit Thermal Rating calculator, predicted curves). Cold water falls less than the wet-bulb, so the approach grows in cool weather.
Cold water against wet-bulb for the example tower (PlantCalcKit Thermal Rating calculator, predicted curves). Cold water falls less than the wet-bulb, so the approach grows in cool weather.

What it does

Merkel rating

Design KaV/L and fill characteristic from your design point; predicted cold water at any wet-bulb, flow, load or fan power.

Four cases at once

For example design, summer peak, extra flow and one fan off.

Fan-off and stopped cells

Natural-draft air through a stopped cell and mixed cold water by mass balance.

Upgrade options

High-efficiency fill, bigger fans or an extra cell — colder water, extra heat load and payback for each.

Measured-test check

Capability from a measured test by the characteristic-curve approach.

Predicted curves

Cold water against wet-bulb for 90/100/110 % flow, ready to print.

Built for engineers

  • Visible formulas — nothing hidden, so you can check every step.
  • Fully referenced — methods from the standard references, checked against their published worked examples.
  • Safe to share — sheets are protected against accidental edits, with an open password so you can still customise.
  • Built-in input checks — clear warnings for impossible inputs and values outside typical ranges.

For engineering estimates; verify against site data. Code-based methods are aligned with the publicly documented procedure; they are not a licensed reproduction or a certification.