Can Cooling Towers Be Used to Conserve Water?
As counterintuitive as this title sounds, cooling towers can be used to save water under the right conditions. A trend in the commercial cooling arena is to move towards air cooled chillers.
The prevailing thought is that these units are better at saving water and lowering operating costs for the local facility. While there may be some element of truth in this for the local facility operator, the truth is a bit murkier when we compare overall electrical power and water consumption for both the local facility and the electric generating power plant where the electrical power is produced.
Air cooled vs water cooled exchangers
In the August 2015 edition of the ASHRAE Journal, an article was published that addressed this topic very well. The introduction to this article compares the efficiency of air cooled heat exchangers vs. water cooled exchangers. Depending on climate and other factors, the air cooled exchanger can be much less efficient because it relies on far more air movement to reject the same amount of heat as the cooling tower, thus consuming much more electrical power. When we look at the overall electrical power usage and the fact that the power generation site still uses water, we can see water savings by using a cooling tower at the local facility.
Managing water use in cooling towers
Of course, all of the water variables with a cooling tower apply in the efficiency calculation. Water losses due to evaporation, blowdown, transient losses through splashing, etc. are all taken into account. Due to the importance of managing overall water use, the author reviews good management practices for cooling tower to manage and control water use through controllers, alternate water sources and through good cooling tower design.
Although with all of the world’s eyes on conservation, sometimes the efforts at the local level are needed to raise awareness for the overall good of conserving resources. As the saying goes, small things done consistently can impart big changes. Maybe the right thing to do is to continue with local conservation efforts to save energy and water, knowing that the larger effort will have bigger gains globally. These are big decisions that are left to the local facility owners and the impact on their community.
Well, not to save the world with this blog post, we’ll let you decide on that. Here is a link to this very good article. Give this a read as it may open your eyes to the use of air cooled heat exchangers and conservation possibilities with water cooled systems.
Increase the efficiency of your cooling towers
For more information, speak to a QualiChem Water Treatment Expert. We’ll help you develop a treatment program for maximizing the efficiency of your cooling tower.