Cooling Towers. You can locate them in any commercial or industrial building, but what exactly is the function of a cooling tower and why is it so important to maintain them?
Types of Cooling Towers
First, let’s begin by identifying the different types of cooling towers that may be in your building. There are generally two types of cooling towers, Natural Draft or Mechanical Draft.
A mechanical draft cooling tower are normally smaller, uses fans to generate air flow and are normally more expensive to run. A natural draft cooling tower facilitates air flow by the natural convection of the air, is normally less expensive to run, however, larger in size than a natural draft cooling tower. In a natural draft cooling tower, as the air becomes warm and moist in the tower, the air flow naturally rises above the cooler air being drawn in from the outside.
Film or Splash
Inside the cooling tower you will find either a Film Fill Media or a Splash Film Media. These film medias are installed to have optimal heat transfer as well as tower efficiency by increasing the amount of contact time and surface area between the air and water. The more time the water is exposed to the air, the more water heat is able to evaporate allowing it to cool down and reach optimal efficiency as a heat rejection device. This ultimately will improve heat transfer and tower efficiency. The film fill allows the water to spread into a thin film which exposes a larger amount of water surface in a smaller compact area, while the splash fill continually exposes more water to the airflow by breaking the falling water into little droplets. Fill and splash fill media both depend on the system having clean water and little to no debris for it to function optimally.
Hazardous Health Issues
As a property owner or manager operating a cooling tower in South Florida, it is safe to say that it is always the “hot” season. However, when summer comes around it goes from hot to “hotter” and with the heat comes also another little nuisance, mosquitoes. As any Floridian is aware of, standing water is a breeding ground for mosquitoes. Since the primary element in a cooling tower is water, maintenance is key to ensure that there is no standing water accumulated which can be a perfect breading ground for mosquitoes.
Another important factor to keep in mind when it comes to standing water is how quickly bacteria can grow as well in that area. Legionella is a bacteria that has been known to form in the standing water of cooling towers that are not properly maintained. Symptoms of Legionella bacteria are coughing, shortness of breath, headaches, muscle aches and even high fever. Simply by inhaling this bacteria through the mist or vapor can cause a person to develop these issues, which is another crucial reason to properly maintain your cooling tower.
ASHRAE recently published a new Legionella standard, ANSI/ASHRAE 188-2015, “Legionellosis: Risk Management for Building Water Systems”.
Standard 188-2015 is applicable to both new construction and existing buildings. It provides information to identify equipment of concern and how to put together a team to build a process to address the concern and then to develop a maintenance plan. Proper preventative maintenance is essential in being proactive in developing a safe environment for you and your occupants.
Calcium Build Up and increased energy expenditure
With water, unfortunately, comes eventual calcium buildup. Constant monitoring of the water in order to ensure that the fill media does not have a large calcium build up, is important in order to proactively avoid any obstructions in the system and to keep your cooling tower running in its most optimal condition.
When the system is neglected or an obstruction has been created, the system can have a higher than desired return water temperature. Consequently, the system would expend more energy and water since it needs to operate at a higher than necessary condensing pressure to satisfy the load. The tower would also be forced to operate longer at a higher fan horsepower since it will be trying to reach the designated cold water temperature. Both of these outlooks would ultimately increase your energy expenditure resulting in an increase in your energy and water bill. Maintaining your cooling towers will not only save you money in your operation budget in the long run but also help you conserve in your energy usage as well.
The concept is simple, the cleaner your tower is, the less work it has to do in reaching its cooling goals, the more stress in the system to reach the goals due to dirty water, the longer the system works to achieve its cooling goals, hence increasing your energy bill.
Increased stress to the cooling tower also results in a decrease in the life of the tower and of course an increase in service and repairs to the system.
Cooling towers, while strong and efficient machines, require consistent upkeep and detailed inspections to ensure that they are operating at peak efficiency. At AC Power & Comfort we can help you create a maintenance plan that will assist you with your HVAC needs in order to provide optimal efficiency to your system. Call Us today at (561)405-5946 or (954)204-8399 or contact us by email at [email protected] to learn more about our preventative maintenance options.
