Some owners of cooling tower systems may want to assess whether a new cooling tower is performing at the same level as the designed specifications after only a few days of installing. However, you may need to run the cooling tower continuously for more than a month before you can decide whether it is performing in accordance with its cooling tower design. This article discusses some of the reasons why extended testing is necessary.
Removal of Processing Agents
Some cooling towers may perform below the level indicated in the designs because the fill material that was used in that tower still has processing agents or films that are lowering the thermal performance of that fill material. For instance, some fill material manufacturers apply a coating on the fill material so that it doesn't degrade during storage. It is therefore necessary to operate the cooling tower for several weeks so that those coatings can be removed as water recirculates within the system. The fill material will then be able to perform at the high level that was indicated in the design specifications.
Allowing Surface Oxidation
Some fill materials, such as rigid PVC, may need to react with the oxygen in water in order to prevent water from beading on their surface. Cooling tower performance has a higher chance of reaching design levels when water can form a film on the fill material instead of beading on the surface of that fill material. Beading prevents complete fill coverage by water. The result is that thermal performance will lower since less water will be able to be cooled by the fill material. Extended test periods allow the fill material to oxidise so that water beading is minimised.
Mineral Deposit Formation
Another key reason why you should test the cooling tower over several weeks is that its performance will keep improving as a thin layer of mineral deposits from the water forms on the surface of the fill material. Those mineral deposits increase the ability of a water film to form on the fill material because the deposits are slick and allow water particles to adhere onto their surface. Such beneficial films cannot form in a few days after the new cooling tower has been set up. Work with the designer and supplier of your cooling tower so that an appropriate testing schedule is formulated for the new cooling tower. You will then be able to avoid making costly adjustments to your new cooling towers that may have had nothing wrong with their designs.