Which Chiller Is Best?

Industrial processes generate large amounts of heat which must be dissipated to avoid damage to sensitive equipment and to protect finished products. One recognised method of monitoring and regulating temperatures at optimum levels involves the use of a chiller system, which can be either water-cooled or air-cooled. This article will focus on the differences between water-cooled chillers and air-cooled chiller systems.

Air cooled chiller vs Water cooled chiller

Although both air-cooled chillers and water-cooled chillers have the ability to remove excess heat from the manufacturing process, they differ in a variety of ways. Determining which chiller type is best for your industrial process depends on several factors, including

Cooler condenser mechanism

Cost differences

Environmental and location considerations

Air cooled condensers vs. water cooled condensers

There is a clear difference between the condenser of an air-cooled chiller and the condenser of a water-cooled chiller. Air-cooled chillers are equipped with a condenser which uses the surrounding air to lower the temperature of the refrigerant. Fans are used to force the air through the tubes containing the refrigerant, thus removing the heat from them. The cooled refrigerant used in the cooler can then be circulated through the entire industrial process to achieve cooling.

Air Cooled Screw Chiller

In contrast, water-cooled chillers use the high heat capacity of water to facilitate the cooling of the refrigerant. The typical coolant used in a water-cooled system is a mixture of water and glycol, which are circulated in a sealed network of tubes. Cooling occurs when the cooled refrigerant passes through a heat exchanger that is connected to the current industrial process. The warm coolant is then sent back to the cooling tower or refrigeration unit to remove the heat gained and prepare it for the next cooling cycle.

Cost differences

Another important factor to bear in mind when comparing air-cooled and water-cooled coolers is the cost of purchase, installation and maintenance.

Through their design and operation, air-cooled chillers appear to be more expensive at face value. Firstly, air-cooled systems will have the installation costs of ducts, fans and temperature regulation controls. In addition, these chiller systems consume a lot of energy to power the fans, thus contributing to the cooling effect of the fans, which will translate into higher electricity costs.

On the other hand, although water-cooled chillers are less expensive to install, they are usually more expensive to run in the long term as most of these chillers require the installation of cooling towers. Similarly, the operating costs of water-cooled chillers can be significantly higher when chiller maintenance costs (e.g. water quality testing, mandatory water treatment costs and operating costs of the refrigeration system) are factored in.

Environmental / location considerations

The planned location of the chiller is another important point to consider when deciding on an industrial chiller. Depending on the site plan, there are advantages and disadvantages to choosing an air-cooled or water-cooled chiller.

Indoor location

Both air-cooled and water-cooled chillers can be installed indoors. However, for air-cooled chillers, other spaces must also be considered. This is because air-cooled chillers need access to sufficient ambient air in order to operate properly.

Placing an air-cooled chiller in a poorly ventilated indoor space will hinder its cooling capacity and reduce its efficiency. In contrast, chillers can be installed in poorly ventilated areas of a building because their cooling towers can be placed on the exterior of the building.

Water Cooled Screw Chiller

Outdoor locations

The choice of air-cooled chillers in outdoor environments is advantageous because of the unrestricted access to the high flow of ambient air required to promote coolant cooling. Water cooled chiller systems are rarely located outdoors.

High temperature environments

Water cooled chillers are the best choice for installation in industrial areas with high heat output. In areas with high chiller temperatures, the performance of air-cooled equipment will be poor as the chillers and cooling towers will struggle to dissipate the heat stored in the coolant pipework.

Where water supply is poor

The choice is easy in situations where water supply is inadequate. In this case, an air-cooled chiller is the best option, provided it is installed in a well-ventilated area. The available water can thus be directed to other production processes that are essential.

Environmental regulations

When choosing a chiller system, local or regional regulations regarding industrial waste water are key issues to be addressed. In this respect, air-cooled chillers are more advantageous as there is no need to worry about releasing waste into the environment.

Chiller efficiency comparison

In comparison, water cooled chillers are more efficient than air cooled chillers. The efficiency of an air-cooled chiller depends on the temperature of the ambient air used in its cooling system. The higher the temperature of the circulating cooling air, the less efficient the air-cooled chiller will be.

Overall, more energy will be spent to repeatedly pump the air through the heat exchanger to achieve the desired coolant temperature.

In contrast, water-cooled chillers are much more efficient because they operate with less dependence on the ambient air temperature. The use of water cooling towers or refrigeration units will ensure that the cooler fluid is regulated consistently within the optimum range and that the industrial processes using these coolers will therefore be properly cooled.