Cooling Tower Approach & Range Calculator
Calculate a cooling tower's range, approach and thermal effectiveness from hot water, cold water and wet-bulb temperatures. Add the circulating flow to get the heat rejected and evaporation loss.
Input
Optional: circulating flow
Leave empty to skip heat rejection and evaporation loss.
Output
| Property | Value |
|---|---|
| No data yet | |
More ways to use this tool
REST API
curl -X POST https://api.iotools.cloud/v1/tool/cooling-tower-approach-range-calculator \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"tempUnit": "c",
"hotWater": "37",
"coldWater": "32",
"wetBulb": "27",
"flow": "",
"flowUnit": "m3h"
}'Swap in your own key from your account. The tool's fields are the body — no wrapper.
Ask an AI agent
Use the IOTools `cooling-tower-approach-range-calculator` tool (Cooling Tower Approach & Range Calculator) on this input:
YOUR_INPUT_HEREPaste this at any agent connected to the IOTools MCP server, then add your input.
Embed widget
<iframe
src="https://iotools.cloud/embed/cooling-tower-approach-range-calculator/"
width="100%" height="520" frameborder="0" scrolling="no" loading="lazy"
title="Cooling Tower Approach & Range Calculator — iotools.cloud"
sandbox="allow-scripts allow-forms allow-same-origin allow-downloads allow-popups allow-popups-to-escape-sandbox"
allow="clipboard-write"
style="width:100%;border:1px solid #e5e7eb;border-radius:12px;overflow:hidden"></iframe>
<script src="https://iotools.cloud/embed.js" async></script>Drop this into your own page — free, no key required, just a link back.
| Cost per API/MCP call | From 5 credits |
|---|---|
| Need more credits? | View pricing |
Also available with
Guides
Work out a cooling tower's range, approach and thermal effectiveness from three temperatures, and optionally the heat it rejects and the water it evaporates at a given circulating flow.
How to use it
- Pick °C or °F.
- Enter the hot water (tower inlet), cold water (tower outlet) and ambient wet-bulb temperatures.
- Optionally enter the circulating flow rate to get heat rejection and evaporation loss.
The formulas
- Range = hot water − cold water
- Approach = cold water − wet-bulb
- Effectiveness = range / (range + approach)
- Heat rejected = flow × 4.186 kJ/kg·K × range
- Evaporation loss ≈ 0.153 % of circulation per 1 °C of range (rule of thumb)
Reading the result
A smaller approach means a larger, costlier tower; approaches below about 3 °C (5 °F) are rarely economical. The cold water can never fall below the wet-bulb temperature, so the approach must be positive.
Limits
Heat rejection assumes water properties near 1 kg/L and 4.186 kJ/kg·K, and evaporation is a rule-of-thumb estimate, not a vendor performance curve.
Privacy
Everything is calculated in your browser; nothing is uploaded.