A crossflow cooling tower is a type of mechanical draft cooling tower where air flows horizontally across the falling water, while the water flows vertically downward due to gravity. This design differs from counterflow cooling towers, where air and water move in opposite vertical directions.
How a Crossflow Cooling Tower Works
- Water Distribution:
- Hot water is distributed over the fill media (heat exchange surface) through gravity-fed distribution basins (or hot water inlet louvers).
- The water flows downward through the fill in a thin film.
- Airflow:
- Air is drawn horizontally across the fill by fans (either induced draft or forced draft).
- The air absorbs heat from the water as they come into contact.
- Cooling Process:
- Evaporative cooling occurs as some water evaporates, removing latent heat.
- Cooled water collects in the cold-water basin and is recirculated.
Advantages of Crossflow Cooling Towers
- Lower Pumping Power:
- Gravity-fed distribution reduces the need for high-pressure pumps.
- Easier Maintenance:
- Large access panels allow easy inspection and cleaning of fill media.
- Handles Dirty Water Better:
- Less prone to clogging since water flows by gravity, not through nozzles.
- Modular Design:
- Can be easily expanded by adding more cells.
- Lower Pressure Drop:
- Air moves horizontally with less resistance than in counterflow towers.
Disadvantages of Crossflow Cooling Towers
- Larger Footprint:
- Requires more space than counterflow towers for the same capacity.
- Potential for Uneven Air Distribution:
- If not designed properly, airflow may be uneven, reducing efficiency.
- Higher Risk of Air Recirculation:
- Warm, moist exhaust air can be drawn back into the inlet, reducing cooling efficiency.
- More Drift Loss (Without Proper Drift Eliminators):
- Water droplets can escape with the exiting air.
Crossflow vs. Counterflow Cooling Towers
| Feature | Crossflow Cooling Tower | Counterflow Cooling Tower |
| Air-Water Flow | Air horizontal, water vertical | Air vertical, water vertical (opposite) |
| Pump Power | Lower (gravity-fed) | Higher (spray nozzles needed) |
| Footprint | Larger | More compact |
| Maintenance | Easier (open structure) | Harder (enclosed design) |
| Efficiency | Slightly lower (longer air path) | Higher (more direct contact) |
| Clogging Risk | Lower | Higher (due to nozzles) |
| Drift Loss | Higher (without eliminators) | Lower |
Applications of Crossflow Cooling Towers
- HVAC systems (large buildings, data centres)
- Power plants
- Oil refineries & chemical plants
- Industrial process cooling
When to Choose Crossflow?
- When low pumping costs and easy maintenance are priorities.
- When dealing with dirty or debris-laden water.
- When space is not a major constraint.