Why It’s Important
- Performance Indicator – A larger cooling range means more heat is being rejected from the process.
- Sizing Factor – The required cooling range influences tower size and fan capacity.
- Process Requirement – Determined by how much the process needs to cool the water.
Cooling Range vs. Approach
Two key terms are often confused:
| Term | Meaning | Depends on |
| Cooling Range | Thot in−Tcold outThot in−Tcold out | Process heat load and water flow rate |
| Approach | Tcold out−Twet bulbTcold out−Twet bulb | Tower’s cooling efficiency and ambient conditions |
Wet Bulb Temperature (WBT) = Lowest temperature achievable by evaporative cooling under local atmospheric conditions.