Chapter 4: Operation
4-1 Bleed-Off and Evaporation Rates
A proper
4-2 Winter Operation Considerations
All cooling towers are subject to ice formation in
Follow these guidelines to reduce the chance of ice buildup:
•Maintain full design flow. Any reduction in water flow greatly increases the probability of ice forming on and around the air inlet louvers.
•Do not use free cooling applications during freezing weather. Reduced water temperatures or loading dramatically increases the chance of ice formation. Make sure that the leaving water temperature is set above 80ºF (27ºC) during
•Do not run fans backward to thaw ice. Ice can form on the fan ring, fan guard, and support structures, and can severely damage fan blades. Reversed airflow can also blow water vapor out onto the roof and create ice fields around the cooling tower.
•Maintain a heat load of at least 60% of tower capacity at all times during operation in freezing weather. A lack of substantial load can create uneven temperatures in the tower and cause freezing.
•If you shut down your cooling tower during freezing weather, you must drain it completely. We recommend that you use an indoor reservoir tank to permit water to drain into the tank on system shutdown, whether for emergencies or actual planned shutdowns.
•An alternative is to use basin heaters if a tower basin is used as a sump. Basin heaters are available as an option. However, basin heaters can permit
Fiberglass Cooling Towers | Chapter 4: Operation | Page 17 of 25 |