COOLING TOWER CHARACTERISTICS
CROSSFLOW COOLING TOWERS
1. Low pumping head, thus lower operational cost.
2. Accepts variations in water flow without changing the distribution system
3. Easy maintenance access to vital parts.
4. Reduced drift loss due to the absence of water droplets.
5. Lower in noise due to absence of water noise.
6. Larger foot print of the tower.
7. Large air inlet surface makes icing difficult to control.
8. Tendency of uneven air distribution through the infill due to the large inlet surface.
COUNTER FLOW TOWERS
1. The coldest water comes in contact with the driest air maximizing tower performance.
2. Smaller foot print of the tower
3. Smaller tower height due to compact infill.
4. More efficient air/water contact due to droplet distribution.
5. Noise production due to spraying and falling water.
6. Direct sunlight in the tower basin might trigger algae growth.
7. Water distribution system might clog due to water borne debris.
8. Uneasy maintenance of water distribution system.
9. Drift loss due to droplet distribution system.
10. Icing of the air inlet louvers in winter time.
CONCLUSIONS AND RECOMMENDATIONS
The air distribution systems for counterflow and crossflow cooling towers have advantages and disadvantages inherent in their respective designs.
Both tower systems are designed to a required cooling tower duty thus the thermal performance and cooling capability for both tower systems, if designed well, are equal.
Crossflow towers should be specified when the following specifications are important:
• To minimize pump head.
• To minimize pumping and piping cost.
• To minimize operating cost.
• When noise limitations are a significant factor.
• When variance in hot water flow is expected.
• When easy maintenance is a concern.
Counterflow cooling towers should be specified when the following specifications are important:
• When space (footprint) is restricted.
• When icing is of extreme concern.
• When pumping is designed for additional pressure drop.