Water-cooled chillers are essential for precise temperature control in demanding industrial and commercial environments. They efficiently manage unwanted heat in large-scale applications by using water to absorb and release thermal energy. This method often makes them more energy-efficient than air-cooled chillers, which dissipate heat directly into the air.

These systems are widely used in:

• HVAC applications for large buildings  
• Manufacturing processes that require precise temperature regulation  
• Data centres where continuous cooling is essential for optimal performance  

The enhanced energy efficiency of water-cooled chillers makes them a preferred choice for organisations committed to sustainability and cost savings.

At Aggreko, we recognise that every cooling challenge is unique. With extensive experience, we provide flexible, high-performance cooling solutions, whether for temporary needs during peak demand or for long-term, scalable installations. Our expertise ensures businesses remain operational, efficient, and resilient, helping customers select the ideal system for their specific requirements. 

Working principle of a water-cooled chiller

Water-cooled chillers operate on the fundamental principles of heat exchange and the vapour-compression refrigeration cycle, effectively removing heat from a process or environment. These systems employ a refrigerant to absorb and transfer heat, with water playing a crucial role in the heat rejection process.

Unlike air-cooled chillers, which release heat directly into the ambient air, water-cooled chillers utilise a cooling tower to efficiently disperse excess heat.

Key stages in operation

• Heat Absorption (Evaporator): Warm water enters the evaporator, transferring its heat to the liquid refrigerant. As the refrigerant absorbs this heat, it evaporates into a low-pressure gas, cooling the water, which is then recirculated.
• Refrigeration Cycle:
  • Compressor: The refrigerant gas is drawn into the compressor, which increases its pressure and temperature.
  • Condenser: The high-pressure, high-temperature refrigerant gas then moves to the condenser, where it releases its heat to a separate stream of cooling water circulating from the cooling tower. As it loses heat, the refrigerant condenses back into a high-pressure liquid.
  • Expansion Valve: The high-pressure liquid refrigerant passes through an expansion valve, which rapidly reduces its pressure and temperature, preparing it to re-enter the evaporator and repeat the cycle.
• Heat Rejection (Cooling Tower): The cooling water, now heated from the condenser, is pumped to an external cooling tower. Here, heat is expelled into the atmosphere, primarily through evaporation and air movement. The cooled water then returns to the condenser to absorb more heat.

What affects a water-cooled chillers’ cooling capacity?

Several factors influence the cooling capacity and efficiency of a water-cooled chiller:

• Load Requirements: The total heat generated by equipment, lighting, and occupancy within the cooled space.
• Ambient Conditions: External temperature, humidity, and climate variations directly impact chiller performance and cooling tower efficiency.
• Water Flow Rate: The volume of water circulating through the chiller and cooling tower affects the rate of heat absorption and rejection.

Conclusion

Water-cooled chillers are indispensable for reliable and energy-efficient temperature control across industrial, commercial, and HVAC applications. By leveraging water and cooling towers for heat rejection, they consistently outperform air-cooled systems in terms of efficiency and capacity, especially in large-scale operations.

At Aggreko, we specialise in delivering high-performance, flexible cooling solutions tailored to unique industry demands. Whether your business requires temporary cooling for peak periods or a robust, scalable long-term chiller system, our expertise ensures seamless and efficient operations. We empower businesses to make informed decisions, securing the right cooling solution to meet their current and future challenges.