Glossary of cooling tower terms

Complete Dictionary of Technical Terms for Cooling Towers

Understanding terminology is the first step to mastering technology. In the cooling tower industry, many specific terms are frequently used. This dictionary is designed to be a comprehensive guide for you, from experienced engineers to those new to the world of industrial cooling.

Air Inlet: The area where ambient air enters the cooling tower.
Approach: The temperature difference between the cold water outlet (cold water temperature) and the wet-bulb temperature of the incoming air. A lower approach indicates more efficient performance.
Atmospheric Cooling Tower: A type of cooling tower that relies on natural air flow (wind) for cooling, without the aid of fans.

Basin: The bottom part of the cooling tower that collects the cooled water before it is pumped back into the system. Often referred to as the cold water basin.
Bleed-Off / Blowdown: The process of periodically removing a small amount of water from the cooling tower system to reduce the concentration of dissolved solids (TDS) and other minerals that can cause scaling and corrosion.
Blowdown Meter: A device that measures the volume of water discharged during the blowdown process.
Building Management System (BMS): A centralised system that controls and monitors various mechanical and electrical systems in a building, including cooling towers.

Carryover: Water carried out of the cooling tower in the form of small droplets along with the outgoing air, rather than as water vapour. Another term for this is drift.
Chemical Treatment: The addition of chemicals to cooling tower water to control scaling, corrosion, algae growth, bacteria, and other microorganisms.
Chiller: A device that cools a liquid (usually water) through a vapour compression or absorption cycle. Cooling towers work in conjunction with chillers to remove heat.
Cold Water Temperature (CWT): The temperature of the water after it has been cooled by the cooling tower before returning to the system.
Cooling Range: The temperature difference between the hot water entering the cooling tower and the cold water exiting the cooling tower. A larger range indicates greater heat removal capacity.
Cooling Tower Institute (CTI): A non-profit organisation dedicated to the research, development, and certification of cooling tower performance and components. CTI certification indicates that a unit has been tested and meets certain standards.
Corrosion: Damage or dissolution of metal materials in cooling tower components and piping caused by chemical reactions with water or the environment.
Crossflow cooling tower is a type of cooling tower in which the water flow falls vertically across the filler, while the air flow moves horizontally.
Counterflow Cooling Tower: A type of cooling tower in which the air flow moves in the opposite direction to the falling water flow.

Drift / Drift Loss: Another term for carryover, which is water droplets carried out of the cooling tower along with the air flow.
Drift Eliminator: A component inside a cooling tower designed to capture water droplets carried by the air flow and return them to the cold water basin, thereby reducing drift loss.

EC Fan (Electronically Commutated Fan): A type of fan that uses a brushless DC motor with integrated electronics, offering very high energy efficiency and precise speed control.
Evaporation Loss: Water that evaporates into water vapour as part of the cooling process. This is the primary means by which a cooling tower dissipates heat.

Fill / Filler: Material inside a cooling tower that increases the surface area of contact between water and air, thereby maximising heat transfer. It can be film fill or splash fill.
Film Fill: A type of filler that forms a thin layer of water on the surface of the material, allowing for highly efficient air-water contact.
Flow Rate: The rate at which water flows through the cooling tower, usually measured in GPM (Gallons Per Minute) or m3/hour.
Fouling: The accumulation of unwanted material (such as mud, dust, sediment, or biofilm) on the surface of the filler, pipes, or other components, which can reduce heat transfer efficiency.

Hot Water Temperature (HWT): The temperature of the water entering the cooling tower after absorbing heat from the cooled system.

Induced Draft Cooling Tower: A type of cooling tower where the fan is placed at the top of the unit to draw air through the filler.
Internet of Things (IoT): A network of physical devices equipped with sensors, software, and other technology to connect and exchange data with other devices and systems via the internet. Used for monitoring and smart control in cooling towers.

Langelier Saturation Index (LSI): An index used to predict whether water is likely to form scale or be corrosive. A positive LSI indicates a tendency to scale, while a negative LSI indicates a tendency to corrode.
Legionella: A type of bacteria that can multiply in cooling towers if conditions are not controlled, and can cause Legionnaires' disease (a type of pneumonia) if contaminated water aerosols are inhaled.

Makeup Water: Clean water added to cooling towers to replace water lost through evaporation, blowdown, and drift loss.

Noise Level: The level of noise generated by a cooling tower, usually measured in decibels (dB). Many modern cooling towers are designed to be low noise or super low noise.

pH: A measure of the acidity or alkalinity of water. An ideal pH range is essential to prevent corrosion and scaling.
Plume: A mist of water vapour visible coming out of the cooling tower as a result of the condensation of hot water vapour mixing with cool air.
Preventive Maintenance: Planned maintenance carried out periodically on cooling towers to prevent damage, maintain efficiency, and extend the unit's service life.

Scaling: The formation of a hard layer (scale) of dissolved minerals on the surface of the filler and other cooling tower components, reducing heat transfer efficiency.
Side Stream Filter: A filter used in cooling tower systems to continuously filter a small portion of the water flow, helping to maintain water quality and reduce fouling.
Splash Fill: A type of filler that breaks water into small droplets as it falls, increasing contact with air.
Sustainability: Practices aimed at meeting current needs without compromising the ability of future generations to meet their own needs. In cooling towers, this relates to water conservation and energy efficiency.

Total Dissolved Solids (TDS): The total amount of all solids (minerals, salts, metals, etc.) dissolved in water. High TDS concentrations can cause scaling and corrosion.
Total Suspended Solids (TSS): The total amount of solid particles suspended in water (not dissolved). High TSS can cause fouling.

Variable Speed Drive (VSD): An electronic device that controls the speed of the fan motor in a cooling tower, allowing the fan power to be adjusted according to the actual cooling load, thereby saving energy.

Water Analysis: The process of testing water samples to determine their chemical and physical composition, which is important for designing an effective water treatment programme.
Water Treatment: The process of managing water quality in cooling towers to prevent scaling, corrosion, fouling, and microorganism growth.
Wet-Bulb Temperature (WBT): The lowest temperature that can be achieved by evaporative cooling. This is the most important environmental factor that determines the performance of a cooling tower.

This glossary will be an invaluable tool for your website visitors, enhancing the credibility of PT Jaya Sakti Internusa as an expert in the field of cooling towers and water treatment.