Common Cooling Tower Problems & Solutions
This article will help you understand Common Cooling Tower Problems & Solutions so you can better care for your commercial or industrial property. Good business starts with a good budget that includes keeping the overhead down. Part of every business is having a clean and comfortable place for customers and clients to do business in. Large commercial properties feature cooling towers and chillers that must work together to keep these spaces cool and comfortable during the hot parts of the year. It is important to know the common cooling tower problems & solutions to help keep your budget under control.
Cooling Tower Problems
Buildings that feature cooling towers must keep track of and control the four major types of water treatment issues. These are biological contamination, corrosion, fouling and scaling. All of these problems reduce the cooling tower’s ability to be as energy efficient as designed. This means they take more electricity to do the same job. This raises your overhead and makes the cost of doing business higher.
Biological Contamination – Cooling towers by nature are places that are hot and humid. Along with the common and plentiful nutrients that most water sources contain it is an ideal place for the growth of unwanted biological growth, such as bacteria. These contaminants aren’t good for people, and are worse for the efficiency of your cooling tower. This comes in the form of biofilm, which is a build up on the internal components of your cooling tower. Even very thin layers can reduce the thermal efficiency dramatically.
Corrosion – Cooling towers and chillers that leak can many times be attributed to cooling systems that are ignored. This can be especially prevalent in cooling towers that use closed loop systems. When the air, sodium, and other chemicals that are found in our water supplies are left unchecked to run through a cooling tower system they eat away at the metal and will lead to leaks.
Fouling – Fouling can occur at different areas of your cooling tower system. The fill is one of the prime locations for fouling to occur. Fouling is the clogging of cooling surfaces or pipes with debris, dirt, and dust. When water cannot make it into and pass through the fill as designed, the air is not cooled properly. This means that the system has to work longer to achieve the same results. Which means it is using more electricity.
Scaling – The primary role of cooling towers are to exchange heat from the chiller or industrial process. This means that build up of minerals in the water can create layers that rob efficiency. The different types of minerals, like calcium, that are part of the high heat system break down and are deposited on the cooling tower heat exchange surfaces. Scaling must be removed or operating costs will increase.
Cooling Tower Solutions
Every cooling tower’s set of problems will be different. The location’s water source, age of the cooling tower, and even the air being used to cool the water varies by location. This means cooling tower maintenance and water treatment is a progressive and customized undertaking. There is no “one size fits all” solution for cooling tower maintenance. Choosing a cooling tower maintenance company that helps control all 4 of the performance diminishing problems will help achieve lower operating costs.
Treating Biological Contamination
The first and last step after you have found that a cooling tower is contaminated with biological growth is to collect a water sample, and it is the last item of business too. Here we will look at the overall order of how you should go about treating a cooling tower system of a biological contamination. The contamination is dangerous to the health of people in the building and near the site as the contaminants can cause respiratory infections. It is treated by shocking the system with chlorine over a series of 48 hours in various concentrations followed by a complete flush and refill with new water.
To prevent future contamination all leaks should be eliminated from the cooling water system. A sample is taken at the end of the cleaning procedure and sent for analysis. If the test comes back positive for L. pneumohphila the chlorination of the water and sampling must be repeated. This is why companies should only hire experienced cooling tower maintenance companies so they avoid unnecessary downtime.
There are 3 ways that corrosion can be controlled, epoxy coatings, adding orthophosphate to the water treatment, or raising the pH of the water up close to 9.0. A delicate balance of these approaches can help extend the life of your cooling tower and the individual components. When the pH is too high cooling tower water cannot be treated as effectively with chlorine treatments that help control the biological contaminants. Orthophospahte does help prevent corrosion as well but it can act as a “fertilizer” for some types micrbiological species. Quality chiller tube coatings and coatings for the cooling tower help protect the metal from carbon steel corrosion.
Fouling in cooling towers causes diminished cooling tower performance which leads to inflated energy consumption. Fouling does this when debris or biological matter prevents the even distribution of water through the system in tubes, nozzles, fill, or other areas where water needs to have unimpeded movement. To treat fouling chlorine can be used, fill can be changed, and nozzles or other hardware can be swapped out for new parts to recover the performance the cooling tower was designed with.
Scaling is a thin coating of minerals or chemicals which insulates the tubes and prevents effective heat transfer, can increase back pressure, and also restric the unit’s generation. Calcium in the makeup water is the main issue that can lead to scaling and should be monitored and treated when necessary. Tube coatings which are made from polymers are one of the ways scaling is prevented. These coatings provide a surface which is conductive to heat to maintain performance but do not give calcium a place to stick to to build up. If there is significant scaling there are cleaning procedures which will remove the scaling, which is a perfect time to use chiller tube coatings to prevent scaling in the future.
4 Keys To Water Treatment
- Make sure your system is consistently controlled for biofilms. It is easier and less expensive to keep it clean, than getting it cleaned.
- Get your bleach fresh, keep it in the shade, and make sure you test it at every delivery.
- Use tests which challenge your assumptions about the variables in your cooling tower with labs for verification and adjust accordingly
- Constant monitoring is the only way to keep on top of your cooling tower scaling, corrosion, and biological growth. Monitor regularly!
Water treatment along with chiller & cooling tower maintenance that involves cleaning all of the heat exchange surfaces is the way to keep your commercial HVAC system operating properly.
Cooling Tower Maintenance & Repair
If you have a business or property that has cooling towers in the Phoenix metro area All Kote Lining, Inc. has the training, tools, and team you. We understand how cooling towers function in the arid Arizona desert and how the makeup water affects the cooling towers and chillers. When you need cooling tower repair, maintenance, or chiller work All Kote can save you money and get the job done quickly. Give us a call today! 480-966-4446.
4 thoughts on “Common Cooling Tower Problems & Solutions”
One of the relevant problem of cooling tower is the freeze.
My question is how to treat the freeze? and to what extend the solution affect on the condenser tubes (made of brass).
With environmental regulations becoming ever more stringent in Phoenix owners and operators need to monitor the quality of water that is being circulated or discharged by the cooling tower.
Thank you for the post on common cooling tower problems and solutions. I never realized how many maintenance issues could go wrong with cooling towers. Not only can the housing be susceptible to corrosion, but also the fan blades themselves and even the piping.