Forced Draft vs. Induced Draft
| Parameter | Forced Draft | Induced Draft |
| Fan Position | Bottom or air inlet side | Top (discharge) |
| Air Movement | Fan pushes air in | Fan pulls air through |
| Internal Pressure | Positive pressure below fan | Negative pressure (suction) |
| Common Fan Type | Centrifugal (pressure blowers) | Axial (propeller) fans |
| Air Distribution | Less uniform, can create dead zones | More uniform across fill area |
| Fan Maintenance | Easier (accessible at ground level) | Harder (elevated, hot humid environment) |
| Recirculation Risk | Higher (discharge air can re-enter) | Lower (vertical high-velocity discharge) |
| Energy Consumption | Higher for same capacity (less efficient) | Lower (more efficient airflow) |
| Freeze Protection | Poor (fan blows cold air into tower) | Better (fan draws air, less direct cold blast) |
| Noise Level | Lower (fan enclosed at bottom) | Higher (fan at top, unmuffled) |
| Ice Formation | Prone at air inlet areas | Less prone |
| Market Share | ~15-20% of mechanical draft | ~80-85% (industry standard) |