During a cooling tower check on a large refrigeration system, if the tower cells have very low water levels, which immediate action is appropriate?

• A. Gradually lower the chiller water set point on the refrigerant system
• B. Increase the cooling tower fan speed
• C. Close the makeup water valve
• D. Shut down the chiller immediately

Answer: (A)

When tower water level is dangerously low, the immediate aim is to reduce the cooling load going to the tower so evaporation and makeup demand don’t outpace supply. Gradually lowering the chiller water set point accomplishes this by reducing how aggressively the system rejects heat to the condenser water loop. With less heat rejected to the tower, the amount of water lost to evaporation drops, giving you a chance for the tower level to recover while you address the underlying issue.

Increasing the tower fan speed would drive more air over the water, increasing evaporation and worsening the low-water condition. Closing the makeup water valve would cut the replenishment, making the situation worse. Shutting down the chiller is a drastic step that stops cooling entirely and isn’t the safest first action when you’re trying to stabilize tower levels. Lowering the chiller water set point offers a controlled way to ease the demand on the tower in the moment.