Daily Archives: June 9, 2017

Even with the best mix and pour concrete deteriorates over time. Reinforced concrete structures require continual maintenance and inspection. This helps find and repair small issues before they compromise the entire structure. Structural elements of the cooling towers are many times made of concrete. Concrete can comprise the foundation, housing for mechanical elements, and even be the liquid containment area. Deterioration occurs in both mechanical draft and natural draft technologies. How quickly the deterioration occurs in these aggressive environments is dependent on regular maintenance. It is also affected by the consistency of the processes. If the processes shift drastically, it can also reduce cooling tower concrete life. This is based on the assumption that the cooling tower’s concrete elements were constructed using the best practices.

Unfortunately for the end user and responsible party for maintaining cooling towers the quality of initial construction plays a very large role in the lifespan of the cooling tower. In addition exposure to unusually harsh chemicals or environmental exposure can accelerate deterioration. Which can lead to structural failures and complete rebuilds or replacements. A quality assessment of the structure will help understand any deficiencies in the structure. Along with an understanding of the cooling tower’s individual environmental load from weather and chemical exposure can help develop deterioration trends. Knowing the current condition and the projected deterioration schedule helps owners project their maintenance costs and cooling tower costs over longer periods of time.

Adequate preparation for the future is the key to successful business. For private companies or public municipalities it is critical to have a plan in place to prepare for all costs. Proper evaluation, investigation, and planning will help understand and plan for the life-cycles of cooling towers. Many owners and civil divisions use an LQQ method for understanding and planning for their assets. This can simplify and make planning maintenance much easier and more effective. An LQQ system means Locating, Qualifying, and Quantifying the condition of the concrete structure. Once the root-cause issues are identified planning can be made to regularly maintain and extend the serviceable life of the concrete cooling tower. This makes the budgeting for these eventualities realistic and avoids surprise maintenance issues that can be fairly costly.

Original Cooling Tower Construction

The costs of conducting effective quality control and quality assurance during the construction phase of concrete cooling tower elements is absolutely critical to the lifespan of the cooling tower. Documentation can be made during the construction phase, yet without visually inspecting during the actual construction there is little assurance that it is being done correctly. The ways that construction mistakes or failures can manifest are varied. Here’s a list of common issues during cooling tower construction.

• Ignoring manufacturer recommendations with regard to construction and application methods.
• Failure to accurately follow the original construction documents.
• Substitution of inferior materials.
• Inaccurate or inappropriate materials specified for construction.
• Substandard construction documentation
• Damage or abuse to the structure during the original construction process.
• Inferior craftsmanship during construction.

Unfortunately many of the defects in the construction process manifest themselves in obvious visual failure until after negotiated warranty periods. This leaves owners or municipalities stuck having to maintain inferior concrete. Maintenance that is far more involved and costly that what is normal wear and tear on the concrete elements of cooling towers. Incorporating the walk through lists that are carefully followed by qualified construction professionals during the concrete construction phase is fundamental in catching and addressing original construction problems.

Simply seeing and fixing a problem area in the concrete isn’t a total repair solution. Owners need to ask for and get root-cause assessments that point to the root reason the concrete is failing or deteriorating more quickly. This will point out a potential quality and longer lasting repair solution. This avoids putting a series of “band aid” repairs on top of each other.

Planning Scheduled Cooling Tower Maintenance

Even if the cooling tower’s concrete is built to specifications everything degrades over time. When a cooling tower in installed a plan should be put in place for the inspection and regular maintenance. This makes predicting expenses easier. It also ensures that the inspections, preventative maintenance and repairs are actually carried out. Many times downtime for the cooling tower is limited and maintenance must be done quickly. During these downtimes deterioration may be noted but not acted upon. These reports are critical in preparation for following scheduled maintenance. Extra time should be scheduled for the repair of any problem areas. The type of damage or issues that might be noted regarding the reinforced concrete structure might include;

• Joint sealant failures
• Wall or base slab cracks that leak water
• Deterioration and/or leaking from expansion joints
• Mechanical penetration leakage
• Deficient foundation support for the cooling tower
• Corrosion of the anchor bolts
• Spalling or corrosion of embedded concrete rebar
• Vegetation or algal growth in the cooling tower
• Deterioration of surface paste or coatings

Each cooling tower structure poses unique obstacles for cooling tower repair contractors. An engineered solution is a must to address each of the issues fully. This is true for both minor and major structural issues. Whether the problem is a crack, foundational stabilization issue, deteriorated containment liner, or halting cooling tower water egress a proper repair strategy should include the following.

1. Inspect and identify the root cause
2. Use the right techniques and raw materials in repair
3. Employ a quality control program for the repairs
4. Hire only qualified and experienced cooling tower repair contractors

Assessing Concrete Deterioration

During the regularly scheduled maintenance it is the responsibility of cooling tower crews to watch for, note, and report any deteriorated sections of the cooling tower. If issues are found a structured assessment should be done. The approach for that evaluation should follow this pattern.

• Find the deteriorated area
• Determine the root cause and affected elements
• Determine what repairs are needed
• Weigh repair vs. replacement for these repairs

One the damage or deterioration is accurately assessed, a detailed and through repair plan be developed. This plan will include variables relevant to each cooling tower’s particular operating environment. It will take into account all of the variables that affect the cooling tower and its concrete. The chemical, construction material, and thermodynamic variables that affect cooling towers should be addressed specifically. This approach should produce a longer lasting repair plan that will increase the serviceable lifespan of the cooling tower.

Quality Cooling Tower Concrete Inspection & Repair

If your cooling tower concrete is showing signs of failure, or if you want to develop a quality maintenance plan All Kote can help. Having a accurate idea of the condition of your cooling tower concrete elements helps with budgeting and avoids unnecessary surprise costs. Call All Kote today to get your appointment scheduled at 480-966-4446.

HVAC systems that keep commercial locations cool create a tremendous amount of heat in doing their job. Cooling towers used in these applications do the job of removing the heat from these systems and keep everything cool and efficient. Vaporization of the latent heat is what helps accomplish this cooling effect. For every pound of water that evaporates in a cooling tower approximately 1,000 BTU’s of heat are removed from the liquid that remains in the cooling tower. The more water that is evaporated, the more cooling power the tower exerts.

All water sources have minerals and solids that are carried in the water that is used in cooling towers. During evaporation the water is removed but the solids remain. They circulate through the cooling tower system and become increasingly concentrated in the water passing through the system. In addition to the salts and solids contained in the water the air used to cool it contain nutrients, dust, gases and microorganisms that are scrubbed out of the air and end up deposited in the cooling tower’s re-circulating water.

Cycles of Concentration

This is a comparison between makeup water and the condition of the water that has been cycled through the cooling tower. The solids carried in the water due to the evaporative nature of the cooling tower and the particulates being scrubbed out of the air contribute to the condition of the water. The industry standard for comparing the source water to the re-circulating water is by measuring the chloride content in both.

Treatment Of Cooling Tower Water

The most sensitive area for water treatment is when contaminated water is re-circulated through the chiller tubes. Certain inorganic substances and biological contaminates are attracted to the heat transfer elements. If these effects are not mitigated by treating the cooling tower water these contaminates collect and coat in the inside of these heat transfer elements. This insulates them and can dramatically reduce the thermal performance of chiller tubes. They can also corrode chiller surfaces and reduce the flow through the chiller overall. Bacteria, scale, biofilm, and corrosion are the four most common issues in the operation of evaporative cooling technologies.

Bacteria Control

For decades the deadly Legionella bacteria has been a recurring problem is cooling towers. The naturally warm environment found in cooling towers along with other biological matter and organic debris help promote the development of the Legionella bacteria. Biocides are used to control the growth of legionella and cooling tower maintenance involves using alternating types of biocides. This alternation of chemicals helps prevent the bacteria from becoming resistant to any one compound. Legionella is relatively difficult to kill because of its resistance to two of the most common water treatment chemicals, bromine and chlorine. Chlorine dioxide and ozone gasses are regarded as highly effective treatments for legionella.

Despite the effectiveness of chlorine dioxide and ozone gasses they are not widely used due to the cost and expertise necessary to administer the program and maintain the equipment that must be used to produce the gasses on site.

Controlling Scaling

Makeup water that is heavy in inorganic salts cooling towers can suffer from scaling on heat exchange equipment. Scaling can prevent the heat transfer surfaces from efficient thermal performance. This will lead to a higher condensing temperature and lower the capacity of refrigerant. In turn the cooling system will require more energy to do its job and will raise the costs. The build up and scaling of calcium is one of the most problematic issues. It precipitates from the solutions at warmer temperatures when in the presence of carbonate alkalinity. Organic polymers and acids are frequently used to prevent and remove these scaling problems. Acids levels must be managed carefully as improper levels of acidity will cause corrosion and premature mechanical failure.

Controlling Biofilm

The systems used in cooling tower systems create an environment for a number of microorganisms. These organisms end up deposited on the metal surfaces in your system and can dramatically reduce your cooling tower’s energy efficiency. These deposits limit the thermal transfer 6 times more so than scaling, due to their higher level of insulation.  To treat the biofilm issues Chlorine Dioxide Gas and ozone are two of the most effective processes. This is due to the fact that these microorganisms are resistant to bromine and chlorine.

Controlling Corrosion

Corrosion is the degradation of metal parts in your cooling tower. This is caused primarily due to the corrosive acidic chemical additives used in cooling towers. There are some microorganisms that also produce acid that has a corrosive effect on the cooling tower. When some chemicals are used to control scaling, bacteria, biofilm and white rust corrosion is a possibility. When corrosion is the result of the chemicals used to control microorganisms it is the fault of the water treatment program. The program should not allow Microbiologically Influenced Corrosion (MIC) but should also not promote excessively high acidic conditions. Once a MIC has been allowed to develop in your system it is hard to eliminate. Prevention is the key to avoid the highly levels of hydrogen sulfide, sulfuric acid, and other corrosive elements.

Controlling White Rust

White rust is possible in new cooling tower systems. It is a serious condition found in new galvanized steel components and cooling towers. They stem from substandard start-up procedures, or the failure to passivate the new cooling tower properly. This condition is made worse by high alkalinity in softened water. Cooling tower manufacturers have guidelines for proper passivation protocols and should be followed when a new cooling tower is installed. While they vary to some degree the use of inorganic phosphates is common. The initial alkalinity should be between 6.5 and 8.0. The heat load should also be controlled during the phase of passivation.

Cooling Tower Water Treatment in Phoenix AZ

If you have a cooling tower in the Phoenix area All Kote’s technicians are highly trained and skilled at chiller and cooling tower maintenance and repair. We can help treat the water, clean the equipment, and apply coatings to help minimize the loss of thermal performance of your HVAC chillers and cooling towers. Give us a call to discuss your industrial cooling towers and what your needs will be in getting the best performance out of your equipment.

Keeping cooling towers clean does more than just improve efficiency, it helps keep occupants healthy. Dirty cooling towers use more energy to do the same job. Also towers that are not kept clean can be breeding grounds for germs and bacteria.

While just about everyone has heard of pneumonia most people aren’t aware that it can be caused by dirty cooling towers. Legionnaries’ disease in cooling towers can spread bacteria and germs. One of those bacteria is the Legionella Pneumophila. The CDC states that “Water within cooling towers is heated via heat exchange, which is an ideal environment for Legionella heat-loving bacteria to grow. “

Regular Cleaning & Disinfection

The way to having clean towers and healthy occupants is regular cooling tower cleaning. OSHA recommends opening up your cooling towers for visual inspection and cleaning on a quarterly basis, or at least twice a year if the cooling tower is not used year round. Addition cleaning and maintenance tips include:

Using Biocides – Control your cooling tower’s bacteria with biocides. This will help keep the water inside your system from becoming overrun with bacteria. It is however limited if there is high levels of dissolved solids or organic matter in your water.

Keep Water Under 68°F – The sump water in your cooling tower should not exceed 68°F, or 20°C. This helps control the development of bacteria. The exact temperature of the sump water varies based on design, flow rate, heat load, and your wet and dry bulb temperatures.

Cleaning Frequency – If the cooling tower isn’t running during the winter time it should be cleaned before use, and at shut down at the end of use in the fall. Cooling towers that run all year long should be cleaned at least once every 3 months.  If the system experiences high bio-fouling due to water conditions the cleaning should be more frequent. New systems and systems that have not been in use for extended period of time should always be cleaned before use.

Monthly Inspections & Online Maintenance

In addition to the semiannual or quarterly cleaning a monthly inspection of equipment should be performed. This helps catch problems while they are small and cost less to address. It also avoids the development and spread of bacteria. To see where you cooling tower bacteria levels are there should be a monthly analysis of the microbiological condition of the cooling tower. Online maintenance includes using biocides and rust inhibitors that are fed continuously during the operation of your cooling tower.

Required Recordkeeping

All operation and maintenance should be logged in a book. This should include all of the activity associated with the cleaning of the cooling tower. That includes the inspections, cleanings, water quality results, bacteria outbreak investigations, and any maintenance done to the tower. Up to date records should be kept that describe the design, components, and make-up water of the cooling tower system.

Additional materials should be made available that detail the proper operation and maintenance of the cooling tower system. This should include the use of corrosion, scale, and antifoaming products used in the cooling tower. Any chemicals added to the system should be recorded to accurately track changes to the development of bacteria in the cooling tower.

Phoenix Cooling Tower Cleaning

If you have a commercial property it is important to keep the cooling tower disinfected and clean. The spread of bacteria from the cooling tower poses and health concern for your visitors and costs you money in energy costs. Before you fire up a cooling tower that has been shut down for the season, or for a longer period of time, it must be inspected, cleaned, and disinfected. This helps fight the spread of disease and cuts down on your overhead. To get your cooling tower cleaned call All Kote Lining at 480-966-4446.

Comprehensive and regular cooling tower maintenance saves time, energy, and money. It also extends the life space of the equipment at your facility.  IAQ, or indoor air quality is a matter of health and comfort in our large industrial and commercial buildings.

The EPA is sighting a number of factors that contribute to diminished air quality in our buildings. Some of these factors are pressure to defer maintenance and building services to reduce costs, reduce ventilation to reduce energy use, the use of tighter construction envelops, and an increase in chemical pollutants in commercial and consumer products. These factors contribute building occupants noticing and complaining about stuffy air, odors, and symptoms of discomfort of illness.

Inadequate Maintenance

Poorly maintained HVAC systems often are the problem when buildings have poor IAQ. The HVAC system can be the ideal breeding ground for the buildup of bacteria. Areas that are common to develop these problems are duct surfaces, cooling coils, and drain pans. When contractors are trying to track down the source of odors the building’s central air conditioning system should be the first place to check. This is especially true in hospitals as they are areas where a greater number of antibiotic resistant superbugs are on the rise. It is a priority to prevent these bacteria and viruses from ever taking root in centralized air management systems.

The use of ultraviolet lights can help control airborne pathogens. In this case the ultraviolet lights need to be the ultraviolet-C type. These lights utilize pathogen killing UV-C energy to inactivate the illness causing airborne pathogens. These systems can be applied to the coil systems in new systems. They can also be retrofitted to work with older technology. Not only does adding UV-C lights help cut down on germs but it also helps address diminished heat transfer or pressure drops due to coils that are fouled. Keeping the coils clean in HVAC systems makes the system run more efficiently and use less energy all year long.

While managers and building owners are aware of IAQ issues, they are also worried about the costs involved in installing and maintaining IAQ products. Some building owner are also skeptical about the claims by IAQ product manufacturers. What needs to be realized is that installing IAQ products does more than help keep air cleaner, but also helps protect air handler coils from bacteria and mold. The cost of installing UV is typically less than 15 cents per cfm. This investment cost is far less than the potential savings achieved through UV system integration. This can be as high as 10-25% in maintenance and energy savings.

Regular HVAC Cleaning

A regular maintenance program is critical to all buildings, but more so of those that use cooling towers. Cooling towers can be a breeding ground for Legionella, which causes Legionnaries’ disease. There is a high demand not only from city, but OSHA, to keep these facilties free of Legionella. The prevention of an outbreak is high priority not only to mitigate risk, but also to improve the health and well-being of building occupants.

The regular HVAC and cooling tower maintenance should include the cleaning of cooling tower basins. The basins are a prime area for the growth of legionella. This is due to the buildup of mud, dirt, and stagnation of water. This tends to develop a biofilm that supports the development of the dangerous bacteria. Cooling tower vacuums can help break up and remove d the silt and mud. This leaves cooling tower basins safer, cleaner, and simply operating more efficiently.

The fill material in cooling towers is also an area in which biofilm occurs. The regular cleaning efforts should include the removal and debris, lime scale, and other biological matter. Fill can be cleaned with pumps to improve water flow, remove scale, and slow the development of bacteria. The fill material can also be removed and upgraded. Newer designs of film help increase water to air contact time, which boosts performance.

Regular maintenance is important in prevention of legionella and bad IAQ. It also helps reduce energy costs, avoids downtime, and helps prevent equipment breakdown.  Regular maintenance is much quicker and less costly than more involved repairs. When systems fail and shut down because of problems the downtime is longer, the repairs more involved, and the cost much higher. This means proactive maintenance programs are much less expensive than waiting for something to go wrong, or people to get sick.

Schedule Your Cooling Tower Cleaning

If you have a HVAC system that is paired with a cooling tower system in the Phoenix area, All Kote is here to help. We want to help you realize the savings in regular maintenance in terms of life span of your equipment, reduce downtime due to larger scale repairs, and generally better air quality in your buildings. Regular cleaning will save you money, keep your employees and customers healthier, and it will help prevent the development of dangerous bacteria like Legionella. Give us a call today to find out how we can help you at 480-966-4446.

If you are searching for “Water Cooling Tower Inspections” you are either looking for a guide to help you understand the process, or you are looking for a company to handle the job for you. Cooling tower maintenance helps save energy, and extends the life of equipment. The type of cooling tower has a huge effect on how inspections are conducted. Large multi-cell industrial cooling tower systems are naturally more involved than small packaged units. This article will help explore elementary considerations in conducting cooling tower inspections that are relevant to the majority of units.  As with most things there are different methods for accomplishing this task, this article covers just one way to conduct a cooling tower inspection.

General Site Conditions

A great practice in cooling tower inspection is to start with a site evaluation. The first thing to look for is if the cooling tower is clutter free. It’s also important to note if there is discharge flume returning to the inlet which is also known as re-circulation. It is also important to note if the discharge from the cooling tower is being evacuated properly not to interfere with the fresh air intakes. The last item to note is if the physical access to the cooling tower is controlled with locked doors, gates, or other personnel controls.

Site & Unit Identification

Knowing which equipment you are inspecting is one of the most critical steps. Different systems have various operating parameters and operation manuals. For thorough inspection to be conducted you should identify the serial number, model number, and manufacturer. If this information is unavailable or there isn’t a nameplate you should take detailed notes for future reference.

Site Environment

Cooling towers operate in various areas and geography. In heavily wooded areas cooling towers can become fouled or contaminated by sources of debris. These include trees that release pollen, have falling leaves, or other similar debris that can cause diminished cooling tower efficiency. In other arid areas there is a danger of the cooling tower being affected by dust, soil, sand and other materials that can get blown into the air and sucked into the cooling tower system. You should also note if there are an industrial processes that might be exhausting chemicals that could be sucked into your cooling tower.

Many times cooling towers capture a significant quantity of sand and dirt from the air. When this happens it can clog nozzles, get trapped in fill material, and coat heat exchange equipment. Each of these conditions diminishes cooling tower efficiency.

Check Process Water

The water that is used as the coolant in the heat exchange system and cooling tower can become contaminated by the various sources of debris. Visually checking the water quality in the cooling tower can be an important step in checking the condition of the system. Check the water temperature at the inlet for its quality. Pay attention to any solids that are either dissolved or in suspension in the water. Generally just ensure that the water is clean. If it isn’t the cooling tower might experience temperature peaks when in use as the water contaminants will cause higher run temperatures.

Unit Inspection List

These are the following areas that need to be inspected cell by cell. As each component is inspected adequate photos should be taken to catalog the condition of the cooling tower for future reference.

Frame Inspection – The frame is the structure the entire unit operates in. You should inspect the frame to check for areas that might compromise the structural integrity of the cooling tower.  Also look for missing or loose cooling tower components.

Pipe Inspection – There are two main pipes that need to be inspected, the pipe that is part of the cooling tower and the pipe that runs beyond the perimeter of the cooling tower. Things to look for are that the pipe is installed correctly and ensure that the pipes are in good condition.

Fill Inspection – The fill needs to be inspected to see if there is any fouling or deposits that would interfere with air or water circulation. If there is physical damage to the fill, fouling, clogging, or uneven water distribution the fill isn’t working up to its design specifications.

Drift Inspection – Drift eliminators are designed to prevent the loss of water during cooling tower operation. During operation air is circulated through the system inspection should note if there is an excessive amount of water exiting the system through the drift eliminators.

Louver Inspection – If equipped the louvers should be inspected to ensure proper installation, condition, and that they are not caked with debris.

Inspecting The Cold Water Basin – The structural integrity of the basin should be inspected much like the frame.  In addition the basin should be inspected for corrosion, leaks, debris, algae growth, even water distribution, particle deposits, anti-vortex devices, and uneven temperature.

Inspecting Hot Water Basins – If the system includes a hot water basin it should also be inspected like the cold water basin. There should be no dry spots, no overflow or signs of overflow, and it should have adequate water distribution.

Mechanical Equipment Inspection – Review the overall condition of mechanical equipment for abnormal vibration, unexpected noises, overall structural integrity, and watch for leaks from any of these cooling tower components. If you are able to check the RPMs, airflow, and amperage of the equipment used in the tower it will help identify faulty mechanical equipment.

 Phoenix Cooling Tower Maintenance

Keeping your energy costs down is a big priority of every commercial and industrial facility in Arizona. HVAC systems are one of the largest draws of electricity for commercial and industrial buildings. Cooling tower inspection and maintenance helps ensure that all of the components are working properly and operating at their highest design capacity. When these components are working properly the cooling tower will run with less energy and will cost your business less. For Phoenix valley cooling tower maintenance call All Kote Inc. at 480-966-4446.

Are you searching for “Spring Cooling Tower Startup“? If so you are probably getting ready to get your cooling tower going again as the year heats up.  With Arizona temperatures that get back into the 80’s in February cooling tower startup happens earlier than other cooler parts of the country. A lot of HVAC systems are shut down for the colder winter months. In the Phoenix valley they are occasionally drained to prevent freezing, but they spend less time down for the winter as opposed to areas that are further north. Winter shut downs provide conditions that are optimal for the development of bacteria. The steps for spring cooling tower startup should be followed and are outlined in this article.

Covered On This Post:

• Cleaning The System
• Fill The Cooling Tower
• Water Quality Control
• Begin Operation
• Water Testing & Validation

Cooling Tower Startup Steps

Bringing the system back online after the period of down time requires following some basic steps. These steps help ensure the best mechanical performance for the hotter months and help ensure the best practices are being followed to avoid the development of Legionella. The recommendations in this article are general for all cooling towers, individual installations and manufacturers might have additional steps to follow. These specific requirements should be followed in addition to general start up steps.

Cleaning The System

All of the wet areas of the cooling tower must be carefully visually inspected. These areas include the wet decks, spray nozzles, water basins, fill materials, water sumps, etc.  All deposits, debris, or deposits should be physically cleaned out by trained personnel. This can be onsite maintenance workers, or more commonly contracted out to a cooling tower maintenance company.  All work done by any workers should be recorded to list out a comprehensive start up cleaning of the system. This is also a good time to conduct an inspection of any permanent filter housings. They should be cleaned thoroughly or media should be replaced if cleaning is not effective.

Fill The Cooling Tower

Open up the valves and put the water back into the cooling system. Next you need to initiate your circulation pumps. Check the system to make sure that water is going through all of the heat exchangers and piping in the system to avoid malfunction. If there are filtration units for the cooling tower water make sure they are online now as well. After the initial circulation you should check the wet decks and spray nozzles for debris that might have kicked loose. Make sure to remove anything you can see and continue to check during the start up period.

Water Quality Control

Water treatment specialists can help you make sure that you cooling tower water program is set up right for your system, your area, and each season. All of the water treatment equipment should be inspected and in clued meters, automated pumps, valves and sensors. They should be inspected, cleaned, and calibrated correctly for maximum efficiency. Sanitation of the cooling tower should be conducted with oxidizing biocides along with bio-dispersants. Your building should have a water management plan, and it will outline any specific requirements for your water management approach.  Only when the water in your cooling tower has been sanitized and confirmed should you start up your cooling tower fans. This procedure should be recorded for future reference.

Begin Operation

With these steps complete the cooling tower can be placed in normal operation mode. Buildings using multiple cooling towers, heat exchangers, and chillers should have a rotating usage plan. This will help ensure that the biocides used to keep the systems clean are regularly circulated when not all units are being used or are online. The specific frequency for each system should be outlined in the water management plan for each building. These steps of rotation help the system avoid bacterial growth, fouling, or deposits.  Even use and distribution of biocides will help ensure that the cooling tower system along with chillers and heat exchange equipment all get even use and none stay stagnant too long.

Water Testing & Validation

Knowing you did the right steps is not enough to ensure that you are controlling the conditions in your cooling tower. Samples should be taken throughout the seasons of use to verify they are effective. This will help avoid the development of Legionella and energy robbing scaling, deposits, and other types of problems with your system. All results of water testing should be recorded in a log book. Certain areas have requirements for buildings with cooling towers and will outline how often the water testing must be conducted.

Cooling Tower Maintenance & Restoration

All Kote Lining is the Phoenix Valley cooling tower experts. We specialize in helping you restore, refurbish, maintain, and repair the cooling tower equipment you already have. This keeps your operating costs down as quality maintenance and repair is much more cost effective than total replacement of your cooling tower or HVAC systems. Give us a call at 480-966-4446 and find out how we can make keeping your customers cool more effective and affordable.

Are you searching for “How Cooling Towers Operate“?  If so this post is designed to help you understand what a cooling tower is, what it does, different types of cooling towers and more. Alle Kote Lining has a wealth of knowledge and experience with cooling tower repair, refurbishment, and maintenance. Cooling Towers are a critical component of our modern industrial and commercial world. How cooling towers operate is a fairly complex question.  In this article we will explain a little about how they help keep our industrial equipment, warehouse, and even shopping centers cool and comfortable.

• What Is A Cooling Tower?
• How Do Cooling Towers Work?
• Types Of Cooling Towers
• Performance Variables
• Built And Delivered or Built On Site

What Is A Cooling Tower?

The processes and machines of industry in addition to the machines dedicated to our own comfort and well-being, produce a tremendous amount of heat.  If that heat is not continuously dissipated those processes or machines will not be able to continue to operate efficiently. Much like the heat from the motor in your car is transferred via a fluid to the radiator; cooling towers continuously transfer heat via a flowing volume of water from the air conditioning condenser or high heat equipment to the cooling tower area.  Final heat rejection is always done through one or another type of heat rejection, but is also exhausted into the atmosphere.

Natural processes of evaporation are very effective heat transfer methods; however they are limited because of their total dependence on random winds and limited surface area. We’ve all experienced those super hot summer days where we are dying for a breeze.  The first and most basic system of evaporation is air flow, which is a natural form of evaporation cooling.  Before man had electricity we had hand held fans, which uses the same foundation concept that a cooling tower does to cause heat exchange and rejection.

How Do Cooling Towers Work?

They are high output heat rejection equipment used for cooling large commercial buildings, power plants or mechanical equipment in industrial applications.  Water that has been heated by either an industrial process or an air conditioning condenser is passed through a cooling tower via a pump system.  That water is then sprayed through nozzles onto pads of material called “fill”.  As the water hits this fill material it is spread as wide as possible to maximize the air-water contact.  The water is then pulled through the system via an electrical motorized fan.

Cooling towers work by extracting waste heat and exhausting it into the atmosphere through the cooling of a stream of water to a very lower temperature.  Cooling towers are a type of hear rejection system that is know as “evaporative”. This is because they allow a small portion of the cooled water to evaporate into a flowing stream of air to cause significant cooling to the remaining stream of water.  Using a hot water system heat and humidity is transferred to the air in the cooling tower.  This raises the temperature of the air and the humidity to 100%, and then with the natural characteristic of hot air, it rises out of the cooling tower a bit like sweat cooling our skin.  Significantly lower temperatures for the cooled water are possible with this evaporation heat rejection technology.

Types Of Cooling Towers

Cooling towers are produced in several types, and even numerous sizes depending on the specific application.  Depending on the heat load different configurations are necessary, and certain sizes will be necessary given the requirements and geographical location.  Knowing which type fits the users requirements is paramount.  Different models have various advantages and limitations.

Crossflow Cooling Towers – With crossflow cooling towers the water flows down vertically through the fill material while the air flows horizontally across the flow of descending water. With this system the air is not required to pass through the distribution system which allows the distribution of by hot water to flowing simply using gravity from hot water basins mounted at the top of the cooling units right above the fill material.

Counterflow Cooling Towers – These cooling towers are designed in a what that air flows directly up, in opposition to the direction of the water flow which is falling directly down onto the fill material. Due to the vertical air flow it’s clearly not possible to use the same open gravity fed system that crossflow cooling towers use.  Instead counterflow cooling towers use pressurized spray systems to distribute the water in a spray on top of the fill material.  Because air needs to be able to rise to make the system efficient the spray nozzles have to be spaced out appropriately.  If this spacing isn’t correct either you will not have a sufficient amount of water on the fill material to maximize it’s potential, or you will restrict the air flow and again, cause the system to run less effectively.

Forced Draft versus Induced Draft – The biggest difference between these two cooling tower distinctions is where the air flow is being applied.  With your forced draft tower types you’ll find that the air flow is being caused by blowers that are located at the base of the air inlet face.  In contrast Induced draft cooling towers utilize a fan that is usually mounted at the top of the unit that pulls the air through the fill media area.

Performance Variables

Every cooling tower and it’s components are designed with a total system approach.  They are engineered to work in union as an integrated system.  This means they will perform more efficiently and will last longer.  Here are some of the variables that are considered when trying to achieve maximum efficiency.

Driveshafts – Much like your vehicle, the driveshaft delivers power from the output of the motor and into a gear assembly.  Due to the inherent moisture in these cooling towers the driveshafts must be constructed of high corrosion resistant materials.  Due to the high RPMs experienced while operating cooling tower driveshafts can be balanced, and re-balanced.  This is much like the balancing of tires on our motor vehicles.  When a driveshaft or tire isn’t balanced it causes vibration and accelerates the degradation of the system.

HVAC Free Cooling – Simply stated HVAC free cooling is a design feature in cooling towers by which cool air from outside is simply taken into the system to save on energy costs.  During certain seasons the air outside your facility is cool enough to work inside the cooling tower and doesn’t need to be processed before entering the cooling tower.  Your cooling tower’s ability to do this is largely controlled by the designer’s choices during the development phase.

Fans – Clearly when you are trying to achieve cooling through the passing of air through water saturated fill materials air flow is elementary.  Cooling tower fans aren’t used in every design, but some are totally reliant on their help to move air through the fill material.  Just like the driveshafts these fans must be made from corrosive resistant materials to cope with the humid environment they must perform in.

Variable Flow – Not all days are made equal, or are equally as hot.  For this reason there are units that are variable flow.  When the cooling tower isn’t under peak demand the air flow can be reduced and the system can consume less energy.  It’s a great way to still get the required cooling but not have to over use your resources.

Nozzles – Counterflow systems require utilize a pressurized, closed pipe system to deliver water to spray nozzles.  These nozzles then spray water onto the fill material.  In crossflow cooling tower systems the hot water is elevated to hot water basins above the fill material.   It is then gravity fed through the distribution basin through nozzles onto the fill material.

Drift eliminators – Much like catalytic converter controls the unused gasoline in our exhaust a drift eliminator controls the unused water droplets exiting the cooling tower.  Water droplets are filtered out of the exhaust system and recirculated back into the cooling tower system.  Doing this cuts down on the water the cooling tower needs to consume.

Fill material – Probably the most important element in the cooling tower is the fill material. It’s designed to maximize the distribution of water for maximum contact with the airflow.  Not just how much air and water come into contact, but in what duration they are mixed defines much of the efficiency of the cooling tower.  There are two basic categories of fill material, splash and film.

Built And Delivered or Built On Site

Cooling towers are generally large assembles.  Factory-Assembled cooling towers are built in factories and then transported via over-sized 18 wheeler transports.  Field-erected cooling towers are built at the site.

Field-erected cooling towers – These towers are constructed at the site they are needed.  They are generally large cooling towers which are produced in smaller, transportable sections.  These sections are numbered so the final assembly can be done on site.  Generally the manufacture will provide supervision and labor for the final assembly. These cooling towers can be made to utilize either counterflow or crossflow air management.

Factory-assembled towers – Depending on the size of the factory-assembled tower it can either be shipped as one large unit or in a number of smaller sections. Large multi-cell units will need to be shipped in sections and assembled at the intended site of use. These towers are also known as “FAP” (factory-assembled product) or “packaged” towers.  These can also be configured with counterflow or crossflow air management.