A cooling tower concentrates everything in its water as it evaporates. Without tight control, three problems build up out of sight:

• Scale on heat exchanger surfaces, cutting efficiency and raising energy costs
• Corrosion of pipes, tubes and the tower itself, shortening the life of the equipment
• Biological growth, including the bacteria that cause Legionnaires’ disease

Manual testing and timer-based bleed and dosing make it harder: water and chemicals are wasted when the timer runs too long, and the tower drifts out of range when it doesn’t run long enough.

A CHEMTROL® cooling tower controller measures the water continuously and acts on what it finds: bleeding, dosing and raising alarms automatically, around the clock.

• Conductivity (TDS) control, with a choice of bleed programs
• ORP control of the oxidising biocide, chlorine or bromine, as standard
• pH control with automatic acid or base feed
• Up to four chemical feeds: inhibitors, biocides, dispersants and more
• Seven feed programs, including percent of make-up flow and a two-week schedule
• Make-up and bleed water meters, and the Langelier Saturation Index for water balance
• Automatic data logging, ready for inspections and audits

Every litre bled from the tower has to be replaced with fresh make-up water. The controller bleeds only when the conductivity calls for it, so the tower runs at the highest safe cycles of concentration rather than a fixed timer setting.

Make-up and bleed water meters show exactly how much water the tower uses, and the chemical feed can follow the make-up flow, so inhibitor goes in step with the water that needs it. Read more: Sustainability: Cooling Towers.

Cooling towers are disinfected with chlorine or bromine. ORP control comes as standard on every CHEMTROL® cooling tower controller: it keeps the biocide where it should be, so the tower stays protected without wasting chemical or overdosing.

For bromine-treated towers, CHEMTROL® controllers can also control on the free bromine level itself, in ppm, with an optional free bromine ppm sensor.

Steady disinfection is the first line of defence against Legionella. Read more: Keeping Cooling Towers Safe.

Corrosion damage is costly and often found too late. Add corrosion rate monitoring to see it as it happens, with adjustable alarms that warn you before it becomes a repair.

An in-line fluorometer measures the inhibitor itself, in ppb, so the controller doses what the water actually needs.

Log in to the CHEMTROL® web-server from any browser to see the controller’s own display, or use the CHEMTROL app for Android and Apple. Change settings, check trend graphs and download all your data, for one site or many. Remote monitoring is standard on the CT6000 and an option on the CT110 and CT3000.

Alerts go out by SMS, email or both, to operators, facility managers and your water treatment technician, so problems are seen and fixed early. Most sites connect through a 4G or 5G router with a SIM card; Ethernet or Wi-Fi work too. See web-access options.

Already running a building management system? Every model can connect to it by Modbus or BACnet, a dedicated alarm relay signals a BMS or PLC directly, and OPTION 420M sends each sensor’s reading as a 4–20 mA signal to your PLC or SCADA system.

• CT110: conductivity and ORP as standard, three chemical feeds and six relay outputs, for a single cooling tower
• CT3000: full chemical automation with four chemical feeds, automatic probe rinse and eight relay outputs; pump control, filter backwash, water level and pressure as options
• CT6000: the fully integrated system, with conductivity, pH and ORP, four chemical feeds, water level, pump control, automatic filter backwash and remote monitoring as standard, and fourteen relay outputs

Free bromine control, corrosion monitoring, fluorometer, BMS connection and 4–20 mA outputs are available on every model.

Each controller is straightforward to install and comes with a detailed installation and operation manual. For a true water sample and reliable sensor readings, it is fitted with a bypass line assembly manifold.

Prefer it ready-built? A CHEMTROL® skid-mounted system arrives assembled and tested. See our work: recent cooling tower installations. Cooling a data centre? See Data Centre Cooling Monitoring.