How important is the proper management of water re-circulated through cooling towers to ensure their thermal efficiency and longevity?

A proper and professional water treatment programme is essential to ensure chiller and tower longevity and efficiency. Water treatment is as important an aspect of a planned preventive maintenance (PPM) programme, as is tube cleaning, oil and filter changes, NDT analysis, bearing inspections, and others.

As a cooling tower maintenance service provider, how do you maximise cycles of concentration (CoC)?

That is a very good question. As a chiller and energy specialist service provider, we look at CoC as a critical aspect of water treatment: The higher you increase the CoC, the more water you can save. In a country such as the UAE, this should be of paramount concern. However, you need to be sure you do not increase the CoC to a level where you can scale the tubes, as this will have a very adverse impact on energy consumption. In addition, high CoC can cause chloride corrosion.

What problems could an increasing amount of dissolved solids in the cooling tower cause?

This could be an issue in chemical water treatment, as additional chemicals will be required to keep the total dissolved solids (TDS) in suspension. Otherwise, you can have tube and tower scaling issues.

What cooling tower treatment programmes do you offer? How do you deal with maintenance issues such as corrosion, scaling and biological fouling?

The primary goals of advanced water treatment in HVAC systems are to prevent mineral scale formation, control biological activity, and inhibit corrosion. These problems traditionally have been addressed by means of chemical activities. Difficult to administer, monitor and control, chemical additives are, ultimately, discharged to the environment, where they can contaminate surface and ground water, concentrate in water treatment plant residuals, and be directly aspirated by people exposed to the mist created by cooling tower drift.

To resolve these problems without using chemicals, Al Shirawi US Chiller Services (USCS) has been recommending and making available in the region the Clearwater Dolphin non-chemical water treatment system technology. In addition to eliminating all chemical usage, this technology will allow the user to increase the cooling tower CoC, thus substantially reducing make up and blow down water requirements and associated costs. It will also reduce the carbon emissions associated with the water production and distribution. In addition, it will allow users to earn points towards LEED certification and comply with the government mandate that all UAE buildings and industries move to a “greener” footprint.

Do you use chemicals in maintaining cooling towers? If yes, how, do you make sure that these chemicals would not have adverse effects on the environment during blow down?

Yes, we do use chemicals in cooling towers. However, we always encourage and recommend the use of the Clearwater Dolphin system. Any time you use chemical water treatment, you will discharge hazardous chemicals into the sewers and drainage systems and aspirate toxic chemicals into the atmosphere.