. By Air Flow Generation
- Natural Draft Cooling Tower
- Uses a tall chimney to create airflow via buoyancy (warm, moist air rises).
- Common in large power plants.
- Mechanical Draft Cooling Tower
- Uses fans to force or draw air through the tower.
- Forced Draft: Fan at air inlet pushes air in.
- Induced Draft: Fan at top pulls air through (more common).
2. By Construction
- Package Type (Factory-built, smaller capacity)
- Field-Erected Type (Built on-site, large capacity)
3. By Air-Water Contact
- Wet Cooling Tower (Open Circuit)
- Direct contact between water and air → some water loss by evaporation.
- Most common type.
- No direct contact; water flows through finned tubes, and air passes over them.
- No water loss, but less efficient.
- Hybrid (Wet-Dry) Cooling Tower
- Combines both methods for water conservation and efficiency.