Cooling Tower Controller Selection Guide

When your customer is ready to add automation or upgrade their cooling tower controller, use our CT Controller Selection Guide to pick the best choice. Even if you have a “favorite” controller that you love, a simple run-through of your system’s operating requirements can help you provide the best system, future-proofed, without spending more money than the system needs. Hey, I’d love to drive a Ferrari but I probably don’t need it for my daily commute. And if you want to just cut to the chase, we have a summary chart here.

Number of Outputs

How many valves, pumps, or other devices do you want to control? Generally, it’s a minimum of a bleed valve, corrosion inhibitor, and 1-2 biocides. But you might want an acid or base pump too. Count the total number of “things” that you want to control. At Lakewood, we have a range of controllers by a number of outputs:

  • Model 140 – 3 outputs
  • Model 1575e – 4 outputs
  • Model 3175 – 5 outputs
  • NexSys – 6 outputs upgradeable to 10. You might use all 10 if you are using one NexSys controller for two cooling towers.

Number of Inputs

Building on your answer to how many outputs you need, how will you control each output? The bleed valve is usually based on system conductivity, inhibitor can be from bleed, makeup water volume or conductivity, and acid/base pumps from pH. Biocides can be dosed on a schedule or based on ORP. How many water meter inputs do you want to use? Trace chemistry? Add all these up, and consider the Lakewood cooling tower controller capabilities:

  • Model 140 – 1 conductivity, 1 water meter
  • Model 1575e – 1 conductivity, 2 water meters, plus one of pH, ORP, or secondary conductivity
  • Model 3175 – 1 conductivity, 2 water meters, plus one of pH, ORP, or secondary conductivity
  • NexSys – 1-2 main conductivity, plus 1-2 makeup conductivity, plus 1-2 pH, plus 1-2 ORP, plus 2-4 water meters, plus 4-8 additional 4-20mA inputs. Need more? NexSys can add a lot, probably more than you need – call us!

Scheduled Feeds

Most chemical programs have some scheduled feeds, and our controllers have a range of capacities for different schedules:

Remote access options

You are probably being asked to cover more accounts than ever before. Remote data access allows you to get system performance data from offsite, and this can help you keep good control without the time of an extra site visit. Our traditional cooling tower controllers (Model 140, 1575e) can give you remote data access via our OnSight Remote Access System, which logs data and creates graphs. This can upgrade your service reports as well as provide remote monitoring including email/text notifications.

The NexSys system logs all system data plus integrates with BACnet and/or Modbus Building Management Systems. Further, the NexSys allows not only remote data monitoring but also remote control of the system, allowing you to change setpoints, deadbands, alarm points, feed schedules, etc. This remote access is standard.

Future Proof It

Finally, think through not only your immediate needs for this system today but where could it progress to? Will you be adding a second biocide in the future? Will you add pH monitoring later? Consider the impact of those choices now to ensure you don’t run into a dead-end with controller limitations later. Our brand-new Model 3175 product platform lends itself well to incorporating new features that are in development!

In the end, this Cooling Tower Control System Selection Guide should help you choose the right controller for your application. Our controllers are available with a 2 day lead time, so there is no waiting to get the best water treatment automation in place for your customer. Contact us with any questions of course!