Air cooled chillers absorb heat from process water, and the heat is then transferred to the air around the chiller unit. This type of chiller system is generally used in applications where the additional heat it discharges is not a factor. In fact, it’s often practical to use the excess heat to warm a plant during the winter, thus providing additional cost savings.
Air cooled chillers require less maintenance than water-cooled units, and they eliminate the need for a cooling tower and condenser water pump. However, since a wet surface will transfer heat better than a dry surface, an air-cooled chiller will tend to consume approximately 10% more power than a water-cooled unit.
Water cooled chillers absorb heat from process water and transfer it to a separate water source such as a cooling tower, river, pond, etc. Industrial water chillers are generally used for large capacity applications, where the heat generated by an air cooled water chiller creates a problem. They are also considered when a cooling tower is already in place, or where the customer requires optimum efficiency of power consumption.
Water cooled chillers require condenser water treatment to eliminate mineral buildup. Mineral deposits create poor heat transfer situations, which reduce the efficiency of the unit.