Data Center Liquid Cooling: How Industrial Water Chillers Support AI Servers and High-Performance Computing:
An Engineer's Guide to Custom Water Chillers, Recirculating Liquid Cooling Systems, and Data Center Cooling Applications

Process Overview

As artificial intelligence, high-performance computing (HPC), and cloud infrastructure continue to evolve, data centers face increasing challenges in removing heat generated by high-density electronic equipment.

Modern processors, graphics processing units (GPUs), and specialized AI accelerators can generate substantial heat within a relatively small physical space. Maintaining acceptable operating temperatures is essential for equipment reliability, computational performance, and continuous operation.

To address these requirements, many data center designs incorporate liquid cooling systems that circulate water or specially formulated coolants through heat exchangers, cold plates, and other cooling components.

According to ASHRAE, liquid cooling is becoming increasingly important as processor power densities rise, particularly in high-performance computing applications.

Industrial water chillers and recirculating liquid chillers can play an important role in these applications by providing controlled coolant temperatures, stable flow rates, and reliable heat removal.

Applied Integrated Systems (AIS) designs and manufactures custom liquid chillers, water chillers, thermoelectric heater/chillers, and integrated heating and cooling equipment that can be configured for specialized data center cooling requirements.

This guide explores how industrial chillers can support data center liquid cooling, where they fit within the cooling infrastructure, and the engineering considerations involved in selecting the appropriate equipment.

At a Glance

Why Data Centers Are Increasingly Using Liquid Cooling

Traditional data center cooling approaches remove heat from electronic equipment primarily through air circulation.

As computing power increases, removing large amounts of heat from densely packed components becomes more challenging.

Liquid cooling offers an effective method of transferring heat because water and other liquid coolants have substantially greater volumetric heat capacity than air. Rather than relying exclusively on air circulation, liquid cooling systems transport heat through a circulating fluid to a heat exchanger or external cooling system.

Important advantages can include:

• Efficient heat removal from high-density electronic equipment.

• Improved control of coolant supply temperatures.

• Reduced dependence on airflow for components cooled directly by liquid.

• Support for compact, high-power computing equipment.

• Flexibility to integrate dedicated cooling loops.

• Potential improvements in overall cooling efficiency when properly engineered.

  
  

The actual energy efficiency depends on the complete cooling architecture, including pumping power, heat rejection equipment, operating temperatures, and whether mechanical chilling is required.

How Water Chillers Are Used in Data Center Liquid Cooling

A data center liquid cooling system typically contains one or more circulating coolant loops.

In a common configuration, a coolant distribution unit (CDU) separates the facility cooling water from the coolant circulating through the IT equipment. The CDU generally includes a heat exchanger, pumps, sensors, valves, and controls.

An industrial water chiller can supply temperature-controlled water to the facility side of a CDU when the application requires active chilling.

Importantly, not every data center liquid cooling installation requires a chiller. Some systems operate at sufficiently high coolant temperatures to reject heat through dry coolers or other heat exchangers without mechanical refrigeration.

For AIS, the most relevant opportunities are applications where dedicated cooling capacity, customized coolant conditions, or independent liquid cooling loops are required.

Where Custom Industrial Water Chillers Can Be Used

1. Dedicated Liquid Cooling for AI Server Equipment

High-performance AI servers generate substantial heat during operation.

A dedicated recirculating water chiller can supply controlled-temperature coolant to a compatible cooling loop or CDU serving a specific group of servers, test racks, or specialized computing equipment.

Potential applications include equipment development, pilot installations, and independent cooling circuits where dedicated cooling capacity is needed.

2. Data Center Cooling Equipment Testing

Manufacturers developing AI servers, GPU cooling assemblies, cold plates, or CDUs frequently need to test equipment under controlled thermal conditions.

A custom industrial water chiller can provide repeatable coolant supply conditions while engineers evaluate:

• Cooling capacity

• Coolant flow rate

• Pressure drop

• Temperature stability

• Thermal response under changing loads

• Equipment performance at different operating temperatures

  
  

This is a particularly attractive application for custom-configured chillers because test equipment often requires operating conditions that differ from standard production installations.

3. Supplemental Cooling for Specialized Equipment

Some data centers contain specialized electronics, instrumentation, or auxiliary equipment that require a dedicated cooling loop.

Rather than modifying the facility's central cooling infrastructure, a separate industrial chiller may provide the required cooling capacity and operating flexibility.

Such systems can be designed around the equipment's required temperature, flow rate, fluid compatibility, and electrical service.

4. High-Purity or Specialized Coolant Applications

Certain electronics and laboratory applications require carefully controlled coolant quality or specialized wetted materials.

For these applications, AIS can evaluate high-purity fluid handling solutions using compatible materials, including fluoropolymer flow paths where appropriate.

However, high-purity DI water or UPW should not automatically be assumed necessary for conventional data center cooling. Coolant selection must follow the equipment manufacturer's water-quality and materials requirements.

Engineering Considerations for Selecting a Data Center Water Chiller

Cooling Capacity

The first step is determining the heat load that must be removed from the equipment.

For a circulating water system, the required cooling capacity depends on coolant flow rate, fluid properties, and the temperature difference between the supply and return.

For water, the relationship can be expressed as:

Q= m x Cp x Delta T

Where:

• Q = cooling capacity (kW)

• m = mass flow rate (kg/s)

• Cp = specific heat capacity (kJ/kg·K)

• Delta T = temperature difference (°C)

  
  

For example, a cooling loop circulating 20 L/min of water with a 5°C temperature rise carries approximately 7 kW of heat.

Actual chiller selection must also account for fluid properties, operating conditions, thermal losses or gains, and an appropriate design margin.

Flow Rate and Pressure Drop

A properly sized chiller must provide the required coolant flow without introducing excessive pressure drop.

Engineers should evaluate piping dimensions, heat exchanger characteristics, filtration, pump performance, and the hydraulic requirements of the equipment being cooled.

Coolant Supply Temperature

The required coolant temperature depends on the equipment design and operating conditions.

Cooling water that is unnecessarily cold can increase energy consumption and create condensation risks.

For liquid-cooled data center equipment, the coolant supply temperature must be coordinated with the allowable equipment temperature range and the surrounding air dew point.

Coolant Compatibility

Depending on the application, a cooling loop may use water, a water/glycol mixture, or a specialized coolant.

The chiller's wetted materials, seals, pump, reservoir, and heat exchanger must be compatible with the selected fluid.

Reliability and Continuous Operation

Data centers often operate continuously, making cooling system reliability a critical design consideration.

Important features may include flow monitoring, high-temperature alarms, pressure monitoring, fault detection, automatic shutdown protection, and integration with facility controls.

Mission-critical installations may also require redundant equipment, backup power, and a cooling architecture that supports maintenance without interrupting service.

The AIS Engineering Approach to Data Center Liquid Cooling

Applied Integrated Systems manufactures custom industrial chillers and recirculating liquid cooling equipment that can be configured around the operating requirements of specialized data center and electronics cooling applications.

Depending on the project, AIS can evaluate:

• Air-cooled or water-cooled chiller configurations.

• Required cooling capacity and operating temperature.

• Recirculating pumps and reservoir arrangements.

• Water and compatible water/glycol cooling loops.

• Application-specific heat exchangers.

• Temperature, pressure, and flow instrumentation.

• Electrical power and communication requirements.

• Custom equipment dimensions and integration constraints.

  
  

For smaller, precision cooling applications, AIS also offers two thermoelectric product families:

Pelti-Therm™ — Refrigerant-free recirculating thermoelectric heater/chillers for compatible heat transfer fluids, including water/glycol mixtures.

Kool-Pure™ — High-purity thermoelectric heater/chillers using PFA fluoropolymer flow paths for contamination-sensitive applications.

These thermoelectric systems are particularly relevant to smaller heat loads and precision applications. Larger cooling requirements can be evaluated using AIS's other chiller technologies such as the Power-Cool™ or the Kool-Pure Plus™ product family.

Rather than requiring customers to adapt their process to a fixed catalog product, AIS engineers configure equipment around the application's operating requirements. AIS does not charge an additional engineering fee for configuring a system to meet the customer's requirements, although specialized development or qualification work, if required, would be separately defined.

Engineering Design Checklist

Before specifying an industrial water chiller for a data center cooling application, consider the following:

[ ] Determine the total equipment heat load and operating duty cycle

[ ] Define required coolant supply and return temperatures

[ ] Confirm the coolant flow rate and allowable pressure drop

[ ] Identify the required coolant and wetted-material compatibility

[ ] Determine whether the chiller supplies a CDU, dedicated loop, or test system

[ ] Evaluate facility ambient conditions and available heat rejection utilities

[ ] Review condensation prevention and leak detection requirements

[ ] Specify monitoring, alarms, communications, and safety interlocks

[ ] Determine reliability, redundancy, and backup power requirements

[ ] Confirm installation dimensions, electrical power, and service access

Key Takeaways

• Liquid cooling is increasingly important for high-density AI servers, GPU computing, and other demanding electronic equipment.

• Industrial water chillers can provide dedicated cooling capacity and controlled coolant temperatures for specialized data center applications.

• Recirculating chillers can support CDUs, independent equipment cooling loops, and electronics cooling test systems.

• Proper chiller selection requires evaluating heat load, flow rate, temperature, coolant compatibility, pressure drop, and reliability.

• Custom-configured chillers are particularly valuable when standard equipment does not match the application's operating requirements.

• AIS can provide application-specific industrial chillers and smaller precision thermoelectric heater/chillers for suitable cooling loads.

  
  

Frequently Asked Questions

What type of chiller is used for data center liquid cooling?

Depending on the facility and equipment requirements, data center liquid cooling may use central chilled-water systems, dedicated industrial water chillers, or coolant distribution units connected to external heat rejection equipment. Some higher-temperature cooling systems do not require mechanical chillers.

Can an industrial water chiller cool AI servers?

Yes. An appropriately sized industrial water chiller can provide cooling to a compatible liquid cooling loop or CDU serving AI server equipment. The complete cooling system must be engineered for the required heat load, coolant quality, flow rate, operating temperature, and reliability.

Can a water/glycol mixture be used for data center cooling?

Yes, in compatible cooling circuits. Glycol mixtures can provide freeze protection and other benefits, but their lower heat capacity and different viscosity compared with water must be considered during system sizing.

Can thermoelectric chillers be used for data center applications?

Thermoelectric liquid chillers can be useful for smaller, specialized cooling applications, including electronics testing, laboratory equipment, and precision temperature regulation. Their suitability depends on the heat load, operating temperature, and heat rejection conditions.

Can AIS manufacture a custom data center cooling chiller?

AIS manufactures custom liquid chillers and recirculating cooling equipment. The engineering team can evaluate the required cooling capacity, flow rate, coolant, electrical service, and integration requirements to determine an appropriate configuration.

Continue the Conversation with an AIS Engineer

Every data center liquid cooling application has unique requirements. Whether you are developing a new AI server cooling assembly, testing a coolant distribution unit, or designing a dedicated recirculating water cooling loop, selecting the right equipment begins with understanding the heat load and operating conditions.

Applied Integrated Systems (AIS) designs and manufactures industrial water chillers, recirculating liquid chillers, thermoelectric heater/chillers, and custom cooling equipment for specialized applications.

Our engineering team can work with you to configure a cooling system that meets your requirements, without additional charges for standard application-specific configuration engineering.

Learn more about AIS's equipment and engineering capabilities at Applied Integrated Systems.

To discuss your data center cooling application, Request for Quote.