Air-Cooled vs. Water-Cooled: The Optimal Chiller Selection Guide

In any commercial and industrial space—whether it’s a data center, a factory, or a high-rise office—powerful and reliable cooling is no longer a luxury; it’s essential infrastructure. These systems are crucial for maintaining operational stability, managing energy, and providing business continuity. For years, the standard approach was cooling systems that use refrigerant to cool the air directly. Today, however, the industry is shifting toward a more advanced, large-scale solution.
This article provides a comprehensive comparison of LG’s air-cooled and water-cooled chillers, exploring the key factors every project planner, building owner, and facility manager should consider to make an optimal choice.

How Chillers Work in a Building

At a basic level, a chiller is a machine that removes heat from a liquid, typically water, using a refrigeration cycle. There are two principal options for this system: air-cooled and water-cooled chillers. The primary difference between them is how they reject the heat from the system—either through the air or through water.
This distinction significantly influences their efficiency, installation, and maintenance strategies.

? How an Air-Cooled Chiller Works?
An LG HVAC air-cooled chiller is a self-contained system that uses fans to release heat directly into the surrounding air. Because it doesn’t require complex components like cooling towers, it offers a simple, compact solution ideal for many projects.

The process is straightforward: large fans draw ambient air across the chiller’s condenser coils. Heat from the refrigerant inside the coils is then transferred to the air and carried away. This all-in-one design simplifies installation and makes air-cooled chillers a flexible choice, especially for retrofitting existing buildings or for sites where space is limited.

? How a Water-Cooled Chiller Works?
An LG HVAC water-cooled chiller rejects the heat from the system to a secondary water loop and cooling tower. This multi-step process, while requiring more infrastructure, is highly effective and delivers superior energy efficiency and stable performance, especially for large-scale applications.

The process begins when heat is transferred from the refrigerant in the chiller’s condenser to a separate loop of cooling water. This heated water is then pumped to an external cooling tower. In the cooling tower, the heat is released into the atmosphere, primarily through evaporation. After being cooled in the tower, the water returns to the chiller's condenser to absorb more heat, completing the cycle. Although this setup involves more components, like cooling water pumps and extensive piping, it is the key to the system’s high efficiency under heavy, continuous cooling loads.

Key Comparison Factors: A Detailed Look

To select the right chiller, it’s essential to evaluate several key factors beyond the initial purchase price. This section clearly breaks down how each system differs and which is more advantageous under specific circumstances.

1. Cooling Capacity and Application Scale

The size of the facility and its required cooling load are the first criteria for determining the chiller type.

? Air-Cooled Chillers are typically the go-to solution for small to medium-sized facilities.
– Air-Cooled Chiller Capacity: 20 to 600 RT (≈70–2,100 kW)
– Common Applications: Educational institutions, mid-sized office buildings, and localized data centers.K94

? Water-Cooled Chillers are engineered for large-scale applications that demand continuous, high-volume cooling.
– Water-Cooled Chiller Capacity: 200 to over 3,000 RT (≈700–10,500 kW)
– Common Applications: Massive data centers, larger manufacturing complexes, and expansive shopping malls.

2. Energy Efficiency and Performance

Energy efficiency is a decisive factor that directly influences a building's total cost of ownership (TCO) and its environmental impact.

* Based on LG internal test of model RCAW030VA2C and RCWFLAP at AHRI temperature condition.
* Comparison of LG chiller models with the same capacity (1,058 kW)

3. Initial Investment vs. Lifetime Operating Costs

The financial decision involves a trade-off between the upfront capital expenditure and long-term operational savings.

Summary: A Strategic Decision for a Sustainable Future

Selecting the right chiller system is a strategic decision that extends far beyond the initial price tag. Project planners and building owners must take a holistic view—considering cooling demand patterns, site installation conditions, long-term energy efficiency goals, and sustainability targets.

By choosing the optimal chiller type, facilities can significantly reduce total cost of ownership (TCO) while improving environmental performance, whether in North America measured in RT or in Europe measured in kW.
LG HVAC’s comprehensive chiller lineup supports this strategic choice.
? LG Air-cooled Chiller available in a wide range of capacities, making them suitable for small to large-scale projects.
? LG Water-cooled Chiller designed with multiple refrigerant and compressor options, delivering flexibility to meet diverse efficiency and sustainability requirements.