COOLING TOWER VS. CHILLER – HOW COOLING TOWERS AND CHILLERS WORK TOGETHER
A cooling tower and an industrial chiller both remove heat, but they serve different parts of a cooling system. A chiller cools process fluid to a controlled supply temperature. A cooling tower rejects heat from condenser water into the outdoor air. Some processes use one system, while water-cooled chiller plants may use both.
How a Cooling Tower Works
A cooling tower removes heat from water through contact with outdoor air. Warm water is distributed over fill material inside the tower while a fan moves air through the unit. A small portion of the water evaporates, removing heat from the remaining water. The cooled water collects in the basin and returns to the process or water-cooled chiller condenser.
Cooling towers require makeup water to replace evaporation, drift, and blowdown losses. They also require water treatment to manage scale, corrosion, and biological growth.
Cooling Tower Construction
A cooling tower is comprised of water pumps and a large basin. The pumps provide water for cooling while the basin collects and drains discharged water from the system. The basin is a large hyperboloid, cylindrical or rectangular structure made of plastic, composite, concrete or steel and contains the spray nozzles, cooling tower fill media, and other heat dispersion equipment.
Although large cooling towers structures (over 200 ft in height and 100 meters in diameter) are common, there are smaller systems that can be installed at smaller sites and on top of buildings.
Cooling Tower Applications
Cooling towers are typically used in large-scale cooling operations such as power generation, oil and gas refining, and thermal power stations. One very important deciding factor on choosing a chiller or a cooling tower should be based on the required coolant temperature.
Cooling tower temperatures vary based on local wet bulb conditions and the ambient air temperature. Typical low temperature coolant temperatures during summer conditions can rarely go below 75F-80F while using a cooling tower. Chillers can achieve typical temperatures from 70F and below all year.
Some chiller designs can allow for cooling temperatures from 70F-100F+ if designed to accommodate such conditions. Again, depending on system design, a chiller can typically hold a closer temperature tolerance with respect to a desired temperature set point.
How an Industrial Chiller Works
An industrial chiller removes heat from hot, gaseous coolant coming from a process using water or heat transfer fluid and transfers this heat to a refrigerant. Then the hot (used) refrigerant is cooled and regenerated with ambient air or water from a tower or outside source, and then returns for recirculation.
Industrial chillers can be air-cooled or water-cooled, depending on the medium for dissipating heat from the system. In air-cooled chillers, the hot coolant which has undergone a phase change into a gas (in the evaporator) is exposed to the air around the system which cools it and turns it back into a liquid. In water-cooled chillers, a cooling tower provides water to cool and condense the coolant.
Cold Shot Chillers has several types of chiller systems available including water-cooled chillers (that use a stream of water from a cooling tower to reject heat from the coolant in the condenser) and air-cooled chillers (that use ambient air and cooling fans to remove heat from the condenser coolant).
Cooling Tower vs. Chiller – Do I Only Need One or Both?
As you’ve now learned, the main difference between a chiller and cooling tower
is in the mode of operation. Cooling towers and chillers can be used independently or in combination for large-scale, efficient cooling.
Before making the decision to utilize both, consider factors such as your required volume of cooling, access to water, available space, and budget. Feel free to use our tools to help make an informed chiller capacity calculation for your application.
How Does a Cooling Tower and Chiller Work Together?
In a water-cooled chiller system, three separate circuits may be involved:
- Process-fluid loop: Chilled fluid travels from the chiller evaporator to the process and returns carrying absorbed heat.
- Refrigerant circuit: Refrigerant moves heat from the evaporator to the condenser inside the chiller.
- Condenser-water loop: Water carries heat from the chiller condenser to the cooling tower, where the heat is released outdoors.
Refrigerant does not normally travel between the chiller and cooling tower. Chilled process water also does not normally flow through the tower. Read more: How does a chiller workÂ
Cold Shot Chillers Has Your Process Cooling Needs Covered
At Cold Shot Chillers, we provide dependable air-cooled and water-cooled industrial chiller systems of varying capacities to suit your budget and application. Our chillers are suitable for a wide range of industrial uses, from craft breweries to medical facilities and petrochemical refineries.
Please contact us online today or call us at 1.800.473.9178 for more information about our products or to request a quote.
