Benefits of water cooled refrigeration systems
Refrigeration does not make "cold", rather it is the process by which heat is removed. When you remove heat you have to put it somewhere. Refrigeration involves one of two systems: air or water cooled.
Water cooled units are used when there is a lack of free air to remove the heat generated by the refrigeration system. Air cooled units have fans which cause noise while water cooled units are quieter. If the area is dusty or greasy, an air cooled condenser can become plugged. There is less maintenance associated with water cooled units.
Cost of remote air cooled units
If there is no free air for cooling, either the air cooled unit or the air cooled condenser can be placed in a remote location. The heat can therefore be released into an area that is cooled or even outside.
A system with an air cooled unit in a remote location is still simple, but there is an additional cost of piping it in. A remote air cooled system is commonly used on larger systems such as in supermarkets. But this system is more complex and expensive to install.
Chilled water or recycled water systems
Chilled water systems use a mechanical refrigeration system and are very expensive and maintenance intensive. As well, chilled water systems create additional heat that must be removed.
Closed loop systems are still complex. You also have pumps and a dry cooler. Larger condensers are required and power consumption may increase.
Outdoor (Roof-Top) Units
Outdoor (roof-top) units are refrigeration system packages designed to operate outdoors under all conditions. They do not use any water and all heat and noise is removed. This kind of system is expensive, however. They cost approximately twice as much as a water cooled system.