Skip to main content

Find your next tool

DashboardAndroid app
Language
Appearance

Plant Engineering Calculator

Updated Sep 18, 2026

Cooling Tower Heat Rejection Calculator — Water Flow, Range & Tons

Calculate rejected heat from circulating-water flow and tower range, with kW, refrigeration-ton equivalent and water mass-flow audit outputs.

Live calculationWorking shownPrivate in browser

Inputs

Results

Range 5.00 °C
Heat rejected 579.6 kW
Equivalent 164.8 TR
Mass flow 27.69 kg/s
More actions

Shared links reopen these inputs. Recent and saved calculations stay in this browser unless you clear site data.

Formula

Q=ρ·Cp·Vdot·ΔT.

Your calculation, step by step

These steps use the values currently entered above so the result can be checked independently.

  1. 1.Tower range = 35.00 − 30.00 = 5.00 °C.
  2. 2.Water mass flow = 997.00 × 100.000 ÷ 3600 = 27.69444 kg/s.
  3. 3.Heat rejected = 27.69444 × 4.1860 × 5.00 = 579.645 kW.
  4. 4.Thermal refrigeration-ton equivalent = 579.645 ÷ 3.5168525 = 164.819 TR.

How to use this calculator

  1. Enter measured or design values using the units shown beside each field.
  2. Review the live results and the substituted calculation steps before using the estimate.
  3. Check the assumptions below, then continue to a related calculator when the next engineering decision needs another model.

Worked example

100 m³/h of water cooled through 5°C rejects about 580 kW using 997 kg/m³ and Cp 4.186 kJ/kg-K.

Assumptions and limits

  • Uses entered/default water density and specific heat.
  • Tower selection still depends on wet-bulb temperature, approach, airflow and vendor rating.
  • Refrigeration-ton equivalent is a thermal conversion, not automatically the same as a vendor nominal cooling-tower rating.

How to interpret the result

Treat the primary result as an engineering screening value, then use the secondary outputs to understand scale, energy or operating impact. Confirm site measurements, equipment limits and applicable standards before making a design or control change.

Questions engineers ask

Why does tower heat rejection use circulating-water range?

The water side loses sensible heat as it cools from hot return to cold supply. Multiplying mass flow by Cp and the hot-to-cold range gives the rejected thermal rate before any vendor-rating/psychrometric detail.

Is refrigeration-ton equivalent the same as nominal cooling-tower tonnage?

Not necessarily. This owner reports thermal kW divided by the refrigeration-ton conversion for comparison. Cooling-tower nominal ratings and chiller condenser rejection conventions can use different reference conditions, so use vendor/CTI rating definitions for selection.

Why is wet-bulb temperature not required here?

Wet bulb governs achievable approach and tower selection, but the measured water-side heat balance only needs flow, density, Cp and range. Use the range/approach and wet-bulb owners to judge thermal capability.

Continue the calculation

Use the next calculator in the same engineering workflow instead of restarting from search.

cooling tower range approachcondenser water flowcooling tower liquid gas ratio
Methodology. MAXScanner shows the governing formula, entered values and calculation outputs so the estimate is auditable. The calculator is a screening aid; assumptions and equipment-specific limits remain part of the engineering review.