Many buildings utilize both a cooling tower and a chiller together. A common design would include putting an evaporative cooling tower on the roof. There are other types of cooling towers that work with chillers as well. The water-cooled chiller should be in the basement or ground floor. Air chillers are typically not paired with a cooling tower. The process of cooling towers and chillers functioning individually and together will be described below.
Chiller and Cooling Tower System Working Together
Steps for How Water-Cooled Chillers Function
A coolant liquid flows into the chiller, either from recirculating water or new water entering the system. The coolant composition is water or water and glycol. This liquid circulates the system. It absorbs heat from your equipment (often referred to as process). When heated this coolant water will be referred to as process water.
In the evaporator, the process water will interact with the refrigerant. The heat of the process water will boil the refrigerant, causing the refrigerant to turn into a low-pressure gas.
Later in the compressor, the refrigerant turns from a low to a high-pressure gas.
After this, the high-pressure gas flows through the condenser. The condenser has cool water (taken from the connected cooling tower). This cool condenser water converts the high-pressure gas into a high-pressure liquid. This leftover, heated water is then sent to the cooling tower to be cooled.
Lastly, the high-pressure liquid flows to the chiller’s expansion valve. Here, the quantity of refrigerant in the evaporator that will interact with this water is determined. Unless it is flushed out, this water will recirculate again, repeating the cycle from the beginning.
Steps for How Evaporative Cooling Towers Function
Heated water is pumped to the cooling tower’s water distribution system. This will be the heated water of the condenser from the chiller. The chiller is relying on the cooling tower to heat this water to refeed it later.
Then, the heated water is transported to the fill and sprayed on the air stream.
Finally, air flows into the tower vent and the tower fills with the help of a large fan(s). This airflow reacting with water causes evaporation to occur. This evaporation will leave behind cool air, which is then collected in the cold-water basin. It is then returned to the condenser of the chiller. The cycle then repeats.
Essentially, chillers will cool the equipment, via transferring chilled liquid on heat transfer surfaces with the heated equipment. This heated process water will then be sent to the cooling tower to evaporate and produce cold condensation water. Finally, this cold water will then be recirculated back into the chiller. This process will then repeat itself in a cycle. An air handling unit can be used in conjunction with the cooling tower and chiller to provide cool air throughout the building. It is used in part of hvac buildings. For commercial buildings they may be equipoped with an economizer, humidifier, or dehumidifier.
What Buildings Need a Cooling Tower and a Chiller?
Large buildings such as hospitals, office buildings, and shopping malls will use a cooling tower and chiller as part of their HVAC system. Additionally, manufacturing buildings, ice rinks, and data centers all may use a chiller and cooling tower for their heated process equipment. In large buildings with high heat loads, it makes sense to combine these systems for maximum efficiency. Often in smaller buildings that have a cooling tower and chiller, it is a portable cooling tower with a relatively small chiller. The size of your building and heat load will greatly impact the type of system and size of the equipment needed.
Chillers & Cooling Towers Need Regular Water Treatment Maintenance
Your commercial chillers and cooling towers need regular chemical water treatment maintenance to operate effectively. Regular water treatment means higher levels of efficiency by reducing heat transfer corrosion, scale, and bacteria. It can save substantial costs on repairs and cleaning due to these issues. The cost of service pays for itself because of this. To schedule a 100% free survey of your equipment to help prevent problems and increase efficiency contact Chardon Labs today! We have a short contact form here or can be reached at (380) 224-7395.
Matt Welsh
Matt Welsh is the Vice President and Water Consultant at Chardon Labs. He helps consult a wide range of customers utilizing various methods of water treatment, from chemical to chemical-free approaches, large and small applications, and across a wide range of geographical influences. With 20 years of water treatment experience, including a wide range of troubleshooting and service in potable water and non-potable HVAC and industrial applications, he is an expert in water treatment chemistry for cooling towers, boilers, and closed-loop systems.
