In 2024, everyone is feeling the climate change. For some, it means sweating more outdoor. For others, it means a sharp rise in air conditioning energy consumption costs in their commercial, industrial and even residential buildings. With global warming, as average temperatures keep rising, so does the demand for cost-effective and sustainable thermal management solutions.
Energy demand for space cooling has risen at an annual average of roughly 4% since 2000 (twice as quickly as for water heating) and is expected to triple by 2050. Cooling towers are one of the most popular solutions when cooling down heat-intensive industrial processes and managing the temperature in diverse structural complexes.
What are Cooling Towers, and how do they work?
A cooling tower is a heat rejection device that extracts unwanted heat from a structure or machine and releases it into the atmosphere. It uses water to transfer the heat from inside the structure to the air outside. Cooling towers are used in industrial buildings that produce significant amounts of heat, such as power plants, refineries, and data centers. They also serve as parts of HVAC systems in large commercial structures like office buildings, shopping centers, hospitals, and hotels.
A broad selection of cooling tower designs and sizes is available for specific applications and varying ambient conditions. That said, all cooling towers aim to increase the contact area of cool air and hot water to achieve faster and more efficient cooling of equipment and indoor spaces.
What are the benefits of using Cooling Towers in your buildings?
Regardless of the type, make or model – cooling towers are cost-effective and highly sustainable air cooling systems. The main advantages of cooling towers over other types of cooling solutions include:
Higher Energy Efficiency
The natural effect of water-to-air heat transfer drastically reduces the electricity demand for cooling. This reduction translates to lower costs, lower power bills, and a decrease in your building’s carbon footprint. This sustainability component is essential if you plan to apply for sustainability certifications like the BREEAM certification.
In addition, modern cooling towers enable great customization and optimization with smart and connected IoT devices. These systems align the energy consumption of the pumps and fans with the required cooling output. Advancements in IoT devices provide real-time data and predictive analytics, improving process controls and enhancing operational efficiency.
Decreased Water Consumption
Traditionally, cooling towers use water to cool the air. However, as water has become a scarce (and increasingly expensive) resource, cooling towers have evolved to conserve it instead of waste it. Today, water towers can reuse gray water to help conserve water resources, and some can employ closed-circuit systems that re-circulate the water in the HVAC system, further contributing to water conservation. In addition, these towers can integrate with advanced water management technologies like the Wint Water Intelligence’s smart water consumption efforts.
Wint offers a dedicated solution to prevent water waste in cooling towers. It lets you monitor water use at the cooling tower and alerts you when water waste is detected. It also fully integrates with API into other building management systems, making it easier to reduce water consumption, prevent leaks and costly repairs, and adhere to your sustainability policy.
In addition, many utilities across North America offer evaporative cooling credits for the monitoring of cooling towers. These credits incentivize the use of systems that enhance water efficiency by providing financial benefits for implementing advanced monitoring and conservation measures. A smart water management solution like Wint can be particularly valuable to increase water efficiency and take advantage of utility incentives.
[ Source: Wint – Water Intelligence ]
Low Maintenance and Long Service Life
Cooling towers feature a small number of complex moving parts and require minimal maintenance over their long service periods. When properly maintained, cooling towers can serve up to 20 years, making them a cost-effective cooling solution. This is especially true today, with modern cooling towers designed for automation, customization, scalability, space efficiency, and increased durability.
The 5 Types of Cooling Towers You Need to Know
The HVAC industry categorizes cooling towers according to several properties, such as:
- Air and water flow direction (vertical or horizontal)
- Source of air movement (mechanical fans or natural convection)
- Fan position and installation
- Heat transfer technique
- Build type
That said, there are five main types of cooling towers used today in commercial and industrial structures:
1. Natural Draft Cooling Towers
As the name suggests, natural draft cooling towers rely on natural air convection to cool the incoming hot water. Cold, dry air flows naturally through the tower and comes into contact with the warm, moist air that has absorbed heat from the hot water stream. The warm air will then naturally flow up, while the cold air falls to the splash fill on the bottom of the tower.
Typically used in large industrial facilities like chemical and power plants, natural draft cooling towers are tall, open chimney-like structures designed to enhance the natural air circulation patterns inside the tower.
One specific design of natural draft cooling towers often used at industrial facilities is the hyperbolic cooling tower. Its shape helps direct the airflow upward, making hyperbolic cooling towers exceptionally efficient, durable, and cost-effective, as they require fewer resources in their construction.
[ Source: COAL HANDLING PLANTS ]
2. Forced Draft Cooling Towers
Forced draft cooling towers employ internal fans to circulate air through the structure to increase its cooling efficiency. Usually utilized in HVAC systems in data centers and commercial buildings, forced draft cooling towers are costlier to deploy and run than natural-draft cooling towers but are more suited for indoor facilities and smaller spaces.
[ Source: FANS Complete Technology ]
3. Induced Draft Cooling Towers
Like forced draft cooling towers, induced draft cooling towers employ fans to pull air through the tower. They are usually larger than forced draft cooling towers with fans on top of the tower.
The name of this type of cooling tower hints at its operation mechanism: the fans located on top of the tower induce moist and warm air out of the tower’s air outlet at a high velocity. This process ensures the hot air is thrown far away from the tower to prevent heat recirculation.
[ Source: ScienceDirect ]
4. Crossflow Cooling Towers
In this type of cooling tower design, the air flows vertically while the water flows horizontally, allowing for more effective heat exchange processes. Often utilized in industrial and commercial HVAC systems, crossflow cooling towers are more efficient than traditional ones but are also more expensive to build and maintain over time.
Crossflow cooling towers use gravity to enhance water-to-air contact, so they need smaller pumps, which makes them more energy-efficient. These types of cooling towers are also more durable and flexible than others. They can ingest a variable water flow and are less likely to become clogged as they don’t employ pressurized water spraying.
5. Counterflow Cooling Towers
Counterflow cooling towers are most suited for extensive industrial facilities like petrochemical plants. In these towers, the water flows down vertically while the air is pushed vertically across the splash fill from the bottom to the top of the structure. These towers are more frost-resistant than crossflow cooling towers, and they use a similar approach to accomplishing effective water-to-air heat exchange.
The upward airflow means that counterflow cooling towers can’t use gravity-flow basins; they use pressurized nozzles to spray the water over the splash fill. This design usually means bigger pumps that are costlier to operate.
[ Source: JMP ]
How to Improve Cooling Tower Maintenance
While cooling towers are ideal for cost-effective large-scale cooling systems, several issues can arise throughout their lifecycle, especially if you don’t adhere to manufacturer requirements for regular maintenance and optimal operating conditions. Fortunately, there are ways to address and mitigate these issues:
1. Maintain Suitable Water Chemistry
When the water circulated through your cooling tower isn’t treated correctly, it can cause many problems that can result in costly repairs. These include corrosion, scaling, bacterial and fungal growth, and increased energy consumption due to the inefficiencies caused by improperly treated water. To prevent chemistry-related issues in your cooling tower, employ adequate water treatment methods according to the manufacturer’s specifications.
2. Address Mechanical Malfunctions
Most cooling towers employ mechanical components to pump water and circulate air. Mechanical malfunctions in these components, through wear-and-tear or damage caused by extreme events, are relatively easy to detect but expensive to resolve. Reduced efficiency and unusually high noise levels indicate a potential mechanical failure and may demand the attention of a professional.
To troubleshoot a malfunctioning cooling tower, inspect it to identify apparent issues such as leaks or damaged structures. Check the water levels and quality to spot any signs of contamination. If there are temperature issues, it’s worth reviewing the performance of fans, valves, and pumps and making the necessary adjustments.
Thermometers and other tools can help you identify the specific problem. Ensure all the tower’s controls and settings are correctly configured, and keep a regular maintenance schedule to minimize malfunction risks in the future. Maintenance can include, for example, replacing filtration media, cleaning filters, or monitoring water usage.
3. Detect and Instantly Stop Water Leaks
Water leaks within your cooling tower system are much harder to detect and potentially much costlier. Cooling towers use vast amounts of water during regular operation, and even a tiny leak can cost thousands of dollars if it remains undetected and unmitigated.
Moreover, with many cooling towers on the roofs of structures, undetected leaks can have catastrophic consequences on the whole structure, potentially causing exuberant costs in water damage mitigation. Water management solutions like Wint can help you save hundreds of thousands and up to millions of dollars annually by detecting water leaks and cooling towers system failures.
Additionally, the Cycles of Concentration (CoC) in cooling towers is a crucial factor for efficient operation. Cycles of Concentration refer to the ratio of dissolved solids in the blowdown water to those in the make-up water. Proper CoC management optimizes water use and minimizes waste. Water management solutions like Wint can help maintain optimal CoC levels by monitoring the flow of water in and out of the cooling tower, ensuring efficient operation and minimizing water waste.
Prevent Water Waste in Cooling Towers with Wint
Cooling towers are a simple but efficient solution for cooling the air in industrial and commercial structures. While they introduce numerous benefits, such as cost-effectiveness and sustainable heat waste management, common issues like water leaks can be challenging to resolve. With real-time leak detection technologies like Wint Water Intelligence, you can detect leakage and prevent water waste in your cooling towers.
Wint is an AI-powered Water Management solution that monitors water usage at the cooling tower and alerts you when the tower unnecessarily wastes water. It can also automatically stop water leaks by remotely shutting off the valve at the source, potentially saving you huge expenses on damage repairs and water waste.
