Unique system aspects may require special equipment or configuration. If there are processes for multiple fluids or different temperatures of the process fluid, it is possible to use a single closed-circuit cooling tower to service both loops.
One option is to use a split coil configuration that can cater to your needs without requiring a second tower. This can provide a cost benefit by eliminating multiple cooling towers while still maintaining the other advantages of a closed-loop system.
There are also options for incorporating upgraded coils when serving heavy-duty applications. ASME coils can be supplied in closed circuit cooling towers so that you can achieve the benefits of a closed-loop system while still meeting requisite standards.
At times, it may make sense to open the loop for less critical applications and reserve the closed-loop system for the processes with the most restrictive operating parameters. This is especially relevant if your facility has both process cooling needs and comfort cooling needs. The process loop can use a closed-circuit cooling tower to achieve the advantages where higher quality water is required while the HVAC loop may use an open cooling tower for supplying condenser water to the air handler.
Related: Closing the Cooling Tower Loop