COOLING TOWERS | All 38 Components Explained

A cooling tower, although simple looking, is made up of 38 different components and systems, as detailed in the list below, to ensure it operates correctly and at optimum efficiency.

For more information, please visit evapco cooling tower parts breakdown.

• Steelwork/ base.
• Cooling tower casing.
• Access door.
• Portable crane.
• Name plates.
• External access/Maintenance. platforms.
• External ladder systems.
• External guardrail systems.
• Ductwork.
• Fan deck.
• Fan guard.
• Fan.

• Fan motor.

• Plume abatement system
• Drift eliminators.
• Warm water basin.
• Warm water basin guard filter.
• Spray pipework/distribution assembly.
• Nozzles.
• Fill pack.
• Attenuation.
• Air inlet louvers
• Air inlet screens.
• Internal access platform
• Cooling water basin.
• Sweeper system.
• Filtration.
• Make up water
• Basin heater system
• Blowdown/ bleed water system.
• General pipe work.
• Control valves.
• Flow regulation valves.
• Pressure gauges.
• Electrical panel.
• Variable speed drive [VSD]/variable frequency drive [VFD]
• Control panel.
• Vibration switches.

If want to read more on Inspecting and Cleaning of a Cooling Tower read our article 'Overview | Inspecting & Cleaning Cooling Towers'.

What are the major components in a cooling tower

Below we will provide an overview of what is inside a cooling tower and what is external to the cooling tower focusing upon the major components required to allow operation.

Steelwork/ base

Usually, when a cooling tower is installed, it will be mounted on a steelwork structure.

The purpose of this structure is to elevate the cooling tower, which will provide a space between the tower and the slab [roof or floor], allowing the pipework to be connected and maintenance activities to take place.

Other uses of the steel structure would be to mount maintenance platforms ladder systems, seismic systems, and wind restraints and allow vibration mounts to be mounted correctly.

Cooling tower casing

The cooling tower casing surrounds and encloses most of the cooling tower parts, such as the basin, the drift eliminators, and the fans. It also contains spray and water, allowing it to fall directly to the basin and not be carried off by the wind.

The casing can be made from galvanized steel, stainless steel, or fiberglass.

Access door

The access doors are usually mounted on the side of the tower casing and are used to gain access into the tower to inspect and complete maintenance.

Portable crane

A portable crane is usually purchased as an option and used to facilitate the removal of the fans and motor.

They are usually supplied to be installed and disassembled easily so that they can be moved and used between towers.

Name plates

The nameplates, although small, are very important because they provide all the general design information of the tower and the fan motors, etc.

They can usually be found mounted near the door.

External access/ maintenance platforms

External access to the tower will be required, and usually, it’s broken into two parts

1. ladders as described below
2. and maintenance platforms

maintenance platforms will usually be installed and bolted to the steelworks structure to provide safe access, which would allow full maintenance of the cooling tower.

They will be found at the access door and sometimes at the cooling tower’s fill to allow cleaning and changing.

External ladder systems

To gain access to parts of the tower for inspection and maintenance, fixed ladders will be needed, which are usually purchased as an option from the cooling tower manufacturer.

Lattice will usually also require a lattice safety cage, an aluminum framework of vertical bars, and hoops that will bolt to the right to the sides of the ladder and are generally recommended by OSHA when the fan deck exceeds 20 feet in elevation.

External guardrail systems

External guardrail systems are usually purchased as an option and consist of posts, top rails, and knee rails which are hot-dipped galvanized.

They are usually installed on the top of the tower to provide sturdy, safe access for easy maintenance of the fan and fun deck.

Ductwork

Ductwork is sometimes used to direct and duct the warm moist air produced from the evaporative cooling process to the atmosphere.

This usually consists of a short circular duct mounted to the top of the tower at a 45-degree angle.

Again this is usually purchased as an option or from the ductwork subcontractor.

Fan deck

The fan deck is the top of the tower, where the warm moist air is discharged.

It is usually surrounded by a guardrail system to allow inspection and maintenance of the axial fans.

Fan guard

The fan guard is the device installed over the rotating axial fan to reduce foreign objects entering the tower when it is not operating and provide protection to any operatives working in the area.

Fan

Two types of fans will be seen, depending upon the type of tower:

1. Axial fan – that is used in the induced tower, where the air is drawn up through the equipment
2. Axial fan – that is used in the forced flow tower, where the air is pushed though the equipment
3. Centrifugal fan – that is used in the forced flow tower, where the air is pushed through the equipment.

Fan motor

Each fan will have a motor that will provide drive to allow the fans to push or pull the air through the unit.

Most commonly, for the induced type tower, the motor will be mounted within the airstream, meaning a focus should be on the anti-corrosion protection to ensure the motor’s longevity.

Plume Abatement System

A plume abatement system is installed to control and reduce the water vapor that can usually be seen above the cooling tower on a cold morning.

This can be required under regulations or local codes.

See our article ‘What causes Cooling Tower Plume?‘ for a short quick explanation with a diagram.

Drift Eliminators

Drift eliminators are installed above the ‘nozzles’ in a counterflow tower and mounted before the air entering the tower body for a crossflow type tower.

Their purpose is to reduce water usage by stopping water droplets from being ejected from the tower ‘drift,’ as they can be easily transported within the fans’ air stream.

In simple terms, the water is removed from the air by changing its direction through the Drift Eliminator.

Warm water basin

The warm water basin is installed at the top of the tower and used, on a crossflow tower, to feed water down into the fill pack to allow the cooling process to start before dropping into the water basin.

The basin can be made from stainless or galvanized to ensure there are no issues with corrosion.

Warm water basin guard filter.

A basin guard filter is supplied by some manufacturers and is installed to sit on top of the warm water basin to filter the water flowing down the fill pack and into the water basin.

The filter media helps clean the water removing any debris and scale before entering the nozzles, protecting them from possible blockages.

Other benefits are:

• Reduction in basis cleaning
• Reduces risk in nozzle blockages
• Protects impellers of the pumps

Spray pipework/distribution assembly

Usually factory fitted and connected to the condenser water system, a range of pipework is installed to transport the warm water, usually from a chiller/condenser, that is to be cooled, to the top of the tower, where it is sprayed or fed, depending on crossflow or counterflow, through the fill pack.

Nozzles

Within the tower and attached to the spray pipework will be ‘nozzles.’ These will be factory-supplied and are used to atomize the warm water into a mist for the evaporative process.

They are usually designed specifically for the type of tower being used and the volume of water needing to be sprayed by them.

• Crossflow Nozzles
• Counterflow Nozzles

Fill pack

Fill packs are a honeycomb/angular corrugations-like structure in which the warm water will flow through, meeting the air drawn through it.

The honeycomb structure allows more efficiency in cooling the water as it creates a much larger surface area.

Commonly, there are two types of fill pack:

• Counterflow [horizontally mounted high level in tower]
• Crossflow [vertically mounted in tower external walls]

Attenuation.

Attenuators are usually used if there are any noise restrictions or calculated noise issues that may be seen in the surrounding areas to the towers,

They can be fitted to the intake or discharge of the units, and sometimes both.

Air Inlet louvers

Purchased as an option usually, air inlet louvres can be mounted outside the fill pack at the air intake. They have a few benefits:

• Help prevent the escape of water from the tower ‘splash out’.
• Containing the water reduces slip hazards from around the tower
• Reduce leaves and foreign objects form entering the tower 
• Stop the penetration of sunlight into the tower, which helps reduce the growth of algae and biofilms etc.

An area that needs to be considered if using standard type louvres is ice build-up in winter. If there is splash out from the tower and it starts to accumulate on the louvre blades, ice could eventually build up – creating blockages and operational issues for the tower.

Air Inlet screens.

Air inlet screens are a mesh, similar to that we see mounted to the back of weather louvres. They are mounted on the outside of the fill pack at the air intake to the tower.

They have two main uses:

• To keep debris out of the tower
• To meet the FM Global Fire requirements of containing the fill inside the tower incase of fire. The inlet screen will stop the fill from falling out risking spreading the fire.

Internal access platform

Internal access platforms are usually provided as an option and are used to gain access around the internals of the cooling tower, allowing maintenance and inspections to take place.

Cooling water basin.

Located at the bottom of the cooling tower, the water basin has two uses:

• is designed to catch and allow recirculation of the cool water from the cooling process back into the condenser system and,
• to provide weight and structure for the tower 

The basin can be made from stainless or galvanized to ensure there are no issues with corrosion.

Sweeper system.

The sweeper system is installed into the bottom of the water basin. It consists of pipework and nozzles that spray pressurized jets across the basin, moving and cleaning away debris that may build up from airborne and general solids from the water. It will usually be used alongside the cooling tower filtration system, helping to maintain the cleanliness and efficiency of the unit.

See our article ‘What is a Cooling Tower Sweeper System‘ for more detailed information.

Filtration.

To maintain the water cleanliness and remove any foreign objects and debris from the condenser water system that may have been introduced within the cooling process [scale, rust, suspended solids, etc.]. There will usually be a separate filtration system installed and operating.

The most common in our world would be the side stream filter, but the use of other types can be seen, including:

• Screen filters
• Plastic disc filters
• Sand filters

Make up water

Makeup water can be provided to the cooling tower basin by 2 means:

• Float type
• Automatic level control

Float Type

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The makeup water system consists of a float valve that, as the water level in the tower, will drop the float, in turn, opening the makeup water valve, allowing the water that is being lost to the cooling process and evaporation to be replaced.

Automatic level control

Connected to a water level makeup control system, multilevel probes are installed in the basin to monitor the water’s depth.

If the sensors note that the water level is low, they will signal the valve to open, allowing the water lost to the cooling process and evaporation to be replaced.

Both systems do the same thing… keeping the condenser system topped up.

Basin heater system

The basin heater is usually used as a protection against the risk of freezing.

They operate as a 24v emersion type heater [like found in our hot water cylinder at home] and are made from stainless steel to ensure protection from corrosion.

Blowdown/ bleed water system.

During the cooling process, a small quantity of water will be removed from the cooling tower via evaporation, which will leave behind its minerals and solids such as calcium, magnesium, chloride, and silica.

As more and more water is removed, the minerals and solids will become more and more concentrated. This concentration could impact the operation of the tower, chiller/condenser, and pipework systems via scaling and corrosion. Reducing the equipment’s effectiveness, efficiency and increasing the requirements for regular maintenance.

To combat the increase in solids, a blowdown/bleed water system will be installed and used.

The system will monitor the water quality in the system and, when needed, will blow down [usually to drain or another tank that will use the water for things like flushing toilets, etc.] a set quantity of water containing the concentrated solids, allowing it to be replaced by fresh, clean better-balanced water.

General pipe work.

For the tower to operate, there will be a requirement for a range of different pipework to be connected:

• Flow and return pipework – to connect the chiller/condenser to the cooling tower
  • Flow will be connected to the cooling tower ‘range’ usually at the top of the tower, that feeds the nozzles or high level warm water basin, bringing the water from the process to be cooled.
  • Return connected at low level to the tower to allow the cooled water to be recirculated back into system.
• Balance pipework [if using more than one tower] – to ensure that the cooling tower basins are balanced and one is not running dry whilst another is overflowing etc. Its a kind of ‘dumb’ pipe.
• Cold Water Feed – to allow fresh water to top up the system due to evaporation and blowdown
• Overflow pipework – this will be connected to allow the water to be discharged under control if the tower basin overflows.

See our article 'Cooling Tower Piping Layout and Diagrams
' for more detail on the pipework and configurations for a cooling tower / consenser water system

Control valves.

Control/actuated/modulating valves will be used to manage the water entering and exiting the cooling tower.

Flow regulation valves.

Flow regulation valves / commissioning stations are installed into the pipework feeding the tower to balance the system and set the correct maximum design flow rate for the tower.

Pressure gauges.

Like most pipework systems, pressure gauges will be installed on the pipework entering the tower and leaving the tower. They will be used for reference during commissioning and if any problems are noted with the tower performance.

Electrical panel.

An electrical panel will be necessary to provide the correct power to the cooling tower, usually from a Local Mechanical Panel or Low Voltage Switch Board.

Variable Speed drive [VSD] / Variable Frequency Drive [VFD]

To ensure that the fan and motors are operating efficiently during different demands and loads, the VSD/VFD will vary the speed of the motor. This helps create a lot of energy savings. 

Control panel.

The tower supplier will usually provide a simple control panel that can be used to control the items directly associated with the unit:

• Electrical On/Off
• Hand/Auto selection
• Makeup water valves and probes
• Water level alarms
• Solenoid valves

Vibration switches.

Vibration switches are used on cooling towers to monitor for any unusual vibrations and, if required, switch off the fan and its motor upon sensing abnormal vibrations.

Frequently asked questions

Is a Cooling Tower a Heat Exchanger?

Yes, it is a type of heat exchanger. Taking warm water and using a combination of ambient airflow, evaporation, and mechanical fans to move the heat from the water to the air, rejecting it to the atmosphere.

Which type of cooling tower is more efficient?

If there is a choice between a Forced flow / Induced flow cooling tower, the Induced tower is more efficient.

What is TDS cooling tower?

Found by testing the water quality for ‘TDS.’ It means ‘Total Dissolved Solids,’ referring to the minerals, solids, and impurities suspended within the water [calcium, magnesium, chloride, silica, etc.]

If the concentration is large enough, it could affect the operation, corrosion, and maintenance requirements of the system.

Usually controlled with water treatment and blowdown systems.

What are the types of cooling towers?

Check out our great article ‘Quick Guide | Types of Cooling Towers and Ponds’

Do cooling towers have filters?

Yes, they can. Towers can be installed with a warm water basin filter, which is a mesh that is laid across the basin, filtering the water from the inlet to the tower.

Also, there are various other filtration devices, such as side stream filters, sand filters, etc.

What types of fans are used for cooling towers?

Usually, there are two types of fans used for cooling towers:
1. Axial flow
2. Centrifugal Flow

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If you are looking for replacement Cooling Tower Parts such as cooling tower fill media, drift eliminators, spray nozzles, cooling tower fans, water level controls, or inlet lovers we can help!  Learn more about the internal functions of a cooling tower and which ones you can replace in this post.  Cooling Tower Products is the largest supplier of cooling tower parts and products! See below for a list of cooling tower parts we sell and a description of each of their functions.

Cooling Tower Parts & Functions

Here are a list of the most common cooling tower parts that might need to be repair or replaced during the life of your cooling tower.

Cooling Tower Fill Media

What is cooling tower fill media? Fill media is by far one of the most important cooling tower parts. It could be considered the middle man of the entire process. Many of today’s cooling towers use efficient plastic film fills or fill media that maximize the surface area for evaporative cooling processes. Water gets distributed onto the fill, which spreads into thin film. This process increases the water-air interface and allows extra heat to evaporate at a fast pace. The major factors in choosing fill media are TSS levels or Total Suspended Solids, intended treatment, water make-up and contamination potential. The 2 basic types of fill media are film type fill media (spreads the water out into a thin layer) and splash type fill media (breaks the water up). There is also fill media for specific types of towers such as crossflow fill media and counterflow fill media.

Cooling Tower Instrumentation

Cooling Tower Instrumentation systems usually include: Flow Meters For Cooling Tower Makeup Water, Blow Down Rate, Water Level Switches For Cold & Hot Water Basins, Thermocouples for Cold & Hot Water Measurement Of Temperature, Vibration Switches and Low & High Oil Level Switches.

Cooling Tower Drift Eliminators

What are cooling tower drift eliminators used for? Cooling tower drift eliminators and heavy duty drift eliminators are parts of a cooling tower that are designed to remove droplets of water from the air and minimize loss of process water. Drift eliminators cause the droplets and air to change direction suddenly. This process causes the water to become separated from the air and put back into the cooling tower.

Cooling Tower Nozzles

What are cooling tower nozzles used for? Cooling tower nozzles are most frequently used in crossflow cooling towers because they use gravity-flow distribution basins. With these types of systems, the water supply is raised to the distribution basins above the fill media and then flows down over the fill (by way of gravity) through the cooling tower nozzles in the basin floor.

Cooling Tower Fans

What are cooling tower fans used for? Cooling tower fans are used to force or push large amounts of air throughout the cooling tower. They must be built to withstand the corrosive effects in which the environment that they operate. These fans are usually loud but there are certain types of low-sound cooling tower fans. Cooling tower fans are used in crossflow, counterflow, induced/forced draft cooling towers. Natural draft cooling towers don’t need fans because they use the natural air flow and different processes that cool the water.

Fan Deck & Fan Cylinder

The deck of the fan is a supporting platform for cylinders of the fan, which also makes an access way to the fan and water distribution system.

Cooling Tower Fan Motor:

Petrochemical & Refinery cooling tower applications need explosion proof fan motors to prevent leaks in heat exchangers. Fan motors need to be manufactured with Earth fault relay and over load relay protection systems.

Drive Shafts

What are cooling tower Cooling tower drive shafts used for? Drive shafts transmit power from the motor’s output shaft into the gear reducer’s input shaft. Drive shafts must also be corrosion resistant due to the harmful environment it which they operate. The drive shaft is the connecting link between the electric motor and the input shaft of the gearbox.

Gear Box:

The different types of gear boxes include A series single reduction gear boxes, A series double reductions gear boxes, single reduction gear boxes and double reduction gear boxes.

Automatic Water Level Controls

Water Level Controls or float switches are manufactured to control water levels automatically. This helps ensure there is always the correct amount of water inside your storage tank. The level controls are typically used to automatically fill water and stop the fill once it reaches the adequate height. These controls can also be installed with LED sensors that will let you know when your levels are getting too low or too high, called high and low level alarms. “Automatic water level controllers switch the motor on whenever the water level drops below a certain level and shuts the motor off when the water rises well above a fixed level.” Water Level Controls

Piping For Water Distribution:

Piping, for water distribution in a cooling tower, is buried underground and should be supported in-ground to prevent thrust loading in the cooling tower because of self weight and water pressure in the pipe.

Air Inlet Louvers

What are air inlet used for? Air inlet louvers or air intake louvers prohibit the sun light from entering the basin, which prohibits algae growth and lowers chemical costs. These louvers also lower the amount of splash-out, which lowers the volume of water and chemical use. Also, you will experience easier basin removal and access. The air inlet louvers in counterflow towers can sometimes become scaly if they are not correctly maintained and cleaned. Scaled louvers lessen the amount air flow which lowers the efficiency of the unit.

Electronic Float Valves

What are electronic float valves used for? Electronic Float Valves are design for cooling tower functionality, brass float valves and electronic water level systems have little maintenance with an extended life. Typically, there are electronic float valve kits available which include the float arm, float valve and float in kits to fit specific applications.

Distribution Valves:

Distribution Valves regulate the flow of hot water to evenly distribute it in cells. The body of the valve in a distribution valve is made withstand corrosive environments.

Cooling Tower Sealants & Coatings

Interior cooling tower coatings, or cooling tower sealants, help prevent corroding, leaking or rusting inside a cooling tower, while exterior coatings protect the outside of the cooling tower from corrosion and rust. Protecting all sides of your cooling tower helps prevent future problems and costly repairs.

Cooling Tower Basin Heaters

What are cooling tower basin heaters used for? Cooling Tower Basin heaters prevent the cold water basin from freezing up during the winter weather conditions and can be used on Evapco, BAC, Marley and other industrial manufacturers’ products. BAC basin heaters are CSA and UL rated. They have strong long lasting copper heating elements to ensure a long-life. The MPT connection is simple to fit into any cold water basin for closed circuit fluid coolers, cooling towers, and evaporative condensers.

Replacement Cooling Tower Parts & Products

We offer replacement cooling tower parts for Marley, BAC, Evapco, Tower Tech, Recold, Imeco, Vilter and Frigid Coil cooling towers. We manufacture parts for all makes and models of cooling towers.

Contact us to discuss your requirements of how does a chiller work with a cooling tower. Our experienced sales team can help you identify the options that best suit your needs.