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Plant Engineering Calculator

Cooling Tower L/G Ratio Calculator — Water-to-Dry-Air Mass Ratio

Calculate cooling-tower liquid-to-gas mass ratio from circulating-water and dry-air volumetric flow with entered densities.

Inputs

Results

Liquid mass flow 997000 kg/h
Dry-air mass flow 920000 kg/h
L/G ratio 1.084 kg/kg
G/L ratio 0.923 kg/kg

Formula

L/G=(Qwρw)/(Qaρa).

Worked example

1,000 m³/h water and 800,000 m³/h dry air at 1.15 kg/m³ gives L/G about 1.09 kg/kg.

Assumptions & limits

  • Use dry-air mass flow when available; humid-air density varies with weather and altitude.
  • L/G alone does not predict tower approach without transfer characteristics.

FAQs

What does this Cooling Tower L/G Ratio Calculator calculate?

Calculate cooling-tower liquid-to-gas mass ratio from circulating-water and dry-air volumetric flow with entered densities.

What should I verify before using the result?

Check units, operating point, measured site data and OEM limits. This calculator is a transparent screening tool, not a substitute for equipment selection or code-required design.

Why are intermediate results included?

Intermediate values expose the engineering chain so you can audit assumptions, compare scenarios and catch unrealistic inputs.

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Last updated: 2026-09-17