What is District Cooling?

In traditional in-building air-conditioning systems, each building is provided with its own refrigeration systems for producing chilled water. Apart from a few larger-scale developments, most buildings which are smaller in size tend to adopt more energy-intensive cooling technologies such as air-cooled packaged units or water-cooled chiller units without a thermal energy storage system.

District cooling offers a sustainable and energy-efficient solution for modern urban development. District cooling systems produce cooling energy, in the form of chilled water, at a central chiller plant. The chilled water is supplied to multiple end-user buildings via a piping network for comfort cooling.

District cooling systems are typically designed as an infrastructure utility service, but they can also be end-user-owned.

Because of economies of scale, district cooling plants can implement more advanced technology such as thermal energy storage, large capacity high-efficiency chillers, and series-connected chiller modules, which reduce overall system energy consumption.

Schematic of District Cooling System
Schematic of a District Cooling System

District cooling is not new and is considered a mature technology with a well-proven track record. According to ASHRAE, the concept of district cooling can be traced back to the 1880s and the first commercial district cooling systems were built in the 1930s. While technology has been around for a long time, it has seen a resurgence of interest in the past few decades, particularly in the Middle East, Europe, and South East Asia.

The centralized production of chilled water for multiple consumer buildings in the same locality provides district cooling systems with economies of scale which enables district cooling plants to adopt technology options such as thermal energy storage, industrial-grade high-efficiency chillers, and series-connected chiller modules which improve on the overall system energy consumption.

In many parts of the world, district cooling is often structured as a utility energy service and offers many advantages similar to the electrical power utilities such as:

  • High service reliability
  • 24×365 service availability
  • Supply availability on-demand
  • Performance Guarantees
    • guaranteed chilled water supply temperature
    • guaranteed cooling capacity

District cooling as an energy service offers building owners the opportunity to outsource the production of chilled water (a non-core aspect of their business) to a dedicated team of professionals, mitigating the uncertainties and risks inherent in building, owning, operating, and maintaining an in-building chiller plant.

Many iconic projects worldwide have successfully adopted district cooling, including:

  • Burj Khalifa in Dubai
  • Marina Bay Development in Singapore
  • Suvarnabhumi International Airport in Thailand
  • Kai Tak Development in Hong Kong
  • Raffles City Chongqing, China
  • Petronas Twin Towers and Kuala Lumpur City Centre, Malaysia
  • Kuala Lumpur International Airport in Malaysia
  • Kuala Lumpur International Airport 2 in Malaysia

The success of these landmark projects is testimony that the technology is a viable low carbon intensity solution for the comfort cooling of the urban environment and is one of the principal reasons district cooling is increasingly being adopted by forward-thinking urban planners worldwide.