Cooling Tower Approach
Calculate cooling tower approach with clear inputs, formula guidance, and practical result checks.
Cooling Tower Approach measurements
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Result
How to calculate cooling tower approach
Cooling tower approach is the difference between the cold water temperature leaving the tower and the ambient wet-bulb temperature — a key performance indicator for cooling tower efficiency.
How the calculation works
Approach = Cold water temperature − Wet-bulb temperature. A smaller approach indicates a more efficient, better-performing tower.
Example
A cold water temperature of 78°F with a wet-bulb temperature of 70°F: Approach = 78 − 70 = 8°F.
Frequently asked questions
How is Result calculated?
Result = [Cold water temperature] − [Wet-bulb temperature].
Is the Cooling Tower Approach free to use?
Yes — every calculator on Simple Calculator Tools is free, runs in your browser, and does not require an account.
Cooling Tower Approach
Approach = Cold water temperature − Wet-bulb temperature. A smaller approach indicates a more efficient, better-performing tower.
Let's understand your cooling tower approach result.
Calculate a result above and this guide will help you interpret it using this calculator's own formula and explanation.
Pro Tips for Cooling Tower Approach
- A well-maintained cooling tower typically achieves an approach of 7-10°F; a rising approach over time can signal fouling or reduced airflow.
- Approach is a design-basis metric — compare actual measured approach against the tower's design specification to assess performance.
Common Cooling Tower Approach Mistakes to Avoid
- Comparing approach measurements taken under very different ambient humidity conditions without normalizing for wet-bulb variation.
When to Use This Calculator
Cooling tower approach is the difference between the cold water temperature leaving the tower and the ambient wet-bulb temperature — a key performance indicator for cooling tower efficiency.