Dry Cooling Tower vs. Wet Cooling Tower
| Feature | Dry Cooling Tower | Wet Cooling Tower (Evaporative) |
| Principle | Sensible Heat Transfer (like a car radiator) | Latent Heat Transfer (evaporation) |
| Water Usage | Very Low. Only minor makeup water for the closed loop. | Very High. Continuous water loss due to evaporation, drift, and blowdown. |
| Cooling Efficiency | Lower and Weather Dependent. Efficiency drops as the ambient air temperature rises. | Higher and More Stable. Relies on the wet-bulb temperature, which is lower than the dry-bulb, allowing for cooler fluid temperatures. |
| Visible Plume | None. Only a hot air plume may be visible in very cold conditions. | Large white plume of water vapor, which is a constant feature. |
| Operating Cost | Higher energy cost for larger fans to move more air. | Lower energy cost for fans, but high cost for water and water treatment. |
| Capital Cost | Typically higher for the same cooling capacity. | Typically lower for the same cooling capacity. |
| Environmental Impact | Conserves water, no chemical discharge, no plume. | High water consumption, potential for chemical discharge (blowdown), and visible plume. |
| Maintenance | Generally lower. No issues with scaling, fouling, or biological growth (legionella) inside the core. | Higher. Requires regular maintenance to control scaling, corrosion, and biological growth. |