A Sustainable Future With District Cooling in Temperate Climates

Hsieh-Min Loy
District Cooling Systems (DCS) have been supplying cooling needs to multiple buildings and facilities for years, yet it is a technology that is still not widely used.

Despite growing concerns on global environmental issues, particularly the depletion of natural resources, available solutions are still not fully implemented to ensure a sustainable future for generations to come.

Studies on future proofing cities have been carried out to identify the risks of climate hazards, resource scarcities and damage to ecosystems facing cities in developing countries and the measures they can take to future proof them. The approach focuses on managing long-term risks with the objective of delivering long-term environmental, social and economic benefits.

The United Nations promotes compact, higher-density cities as a key sustainable development model to improving urban life.

The United Nations promotes compact, higher-density cities as a key sustainable development model to improving urban life. By increasing the number of inhabitants per area of space, urban sprawl can be reversed, bringing people closer to amenities and health care, therefore, reducing travel time, cost and gas emissions.

However, there is caution when cities are built-up too densely as it can have a negative impact on the environment, triggering the urban heat island (UHI) effect that causes the temperature in its surroundings to rise. UHI is predominantly the result of an increase in heat retention in exposed surfaces and heat generated by activities from the buildings as well as the building services systems. Fortunately, this can be avoided or mitigated through good urban planning – usage of green roofs and lighter coloured surfaces; increased planting of trees and vegetation within the metropolitan area; reducing waste heat through retrofitting buildings and utilities to be more energy efficient; and utilisation of common services tunnels.

For example, during the planning of the Marina Bay area development in Singapore, the Urban Redevelopment Authority (URA) integrated the design and construction of a state-of-the-art underground common services tunnel to house telecom cables, power lines, water and wastewater infrastructure as well as provision for pneumatic refuse collection pipes in a central location. Today, the tunnel caters to both commercial and residential buildings within Marina Bay Financial Centre and One Raffles Quay as well as Marina Bay Sands Integrated Resort.

DCS is especially beneficial as it eliminates the need for individual buildings to be equipped with its own chillers, cooling towers and pump room; reducing end-users maintenance and operational costs...

The common services tunnel also facilitates the implementation of District Cooling Systems (DCS) which supplies chilled water for air conditioning of buildings through a network of pipes in the tunnel. Particularly in densely populated areas where air conditioning has become a necessity, DCS is especially beneficial as it eliminates the need for individual buildings to be equipped with its own chillers, cooling towers and pump room; reducing end-users maintenance and operational costs while optimising the building’s rentable space. Additionally, the higher the ratio of cooling load to the unit of land area served by the district cooling, the lower the per-user cost of the network. When properly employed, surplus heat can also be harnessed from DCS to provide hot water.

As a large central utility plant, DCS takes advantage of economies of scale allowing it to operate at a more energy efficient and economical rate than several smaller systems. This is because various forms of practices can be applied including thermal ice storage where ice is produced during off-peak hours to be used as chilled water during peak periods, reducing the electricity demand for the chilled water system.

It is also flexible in its capacity design and installation as DCS is able to increase its capacity gradually to meet the growing loads in comparison to single-building systems that are unable to. Moreover, it is more reliable as DCS ensure uninterrupted 24/7 operations with system reliability at 99.99%.

As cities continue to grow and urbanisation issues become increasingly complex, integrated solutions are required to build and ensure a sustainable future.

As cities continue to grow and urbanisation issues become increasingly complex, integrated solutions are required to build and ensure a sustainable future. Master planning for urban future requires foresight, innovation, investment and support from the public. The common services tunnel whilst expensive to build is warranted when all major services are incorporated into a shared infrastructure that is easy to operate and maintain, efficient, conserves energy and space, and is economical for end-users. In the long run, it is money well spent!

To learn more about the potential of District Cooling Systems as a sustainable solution, join me at the 3rd Annual Asia Pacific District Cooling Conference on August 27th in Kuala Lumpur where I will be presenting on the topic: "District Cooling for the tropics; a solution towards sustainable asset management."

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