When you flick the switch on a typical air conditioning unit, you’re setting off a process that hasn’t traditionally boasted green credentials.
Conventional cooling devices account for as much as 10% of all global greenhouse gas emissions, according to the World Bank. It predicts that, if left unchecked, emissions from cooling will double by 2030.
Air Conditioning’s potential impact on the environment grows even starker over the longer term, as temperatures in big cities that we currently regard as extreme potentially become the norm within 30 years. This will mean a global increase in demand, and in regions not normally associated with air conditioning, such as northern Europe.
However, the International Energy Agency (IEA) predicts that the majority of demand growth will come from emerging economies, particularly in Southeast Asia. The region, where currently only 15% of the population has access to air conditioning, is predicted to see “skyrocketing” sales of units over the next 20 years.
Finding a way to sustainably keep the region cool is critical and some cities may have found the answer – district cooling.
As one of the hottest and most humid countries, Singapore is heavily reliant on year-round air conditioning. With so many office and residential buildings relying on traditional cooling units, which emit heat, it’s no wonder the city is warming twice as fast as the rest of the world.
So effective is its power to achieve sustainable cooling on a grand scale that the United Nations calls district cooling a “secret weapon” in the battle against climate change
Singapore’s Marina Bay financial district, offices, shops, hotels, and restaurants are all kept cool by one source: the world’s largest underground district cooling system.
Based around a central subterranean plant, the system channels water along 5 kilometers of closed-loop pipe network, giving it the power to lower temperatures across a substantial neighborhood of buildings. Cold supply water flows along the pipes, entering the heat exchanger in each building, where it absorbs heat and cools the building before making its way back to the central plant.
District cooling systems are also cost-effective, since it is cheaper to chill many buildings together than each one individually: in Marina Bay it is estimated that the system cuts energy demand for cooling by 40% – the equivalent energy usage of 24,000 apartments in the city-state.
Capital costs for district cooling systems are lower, too, as there’s no need for individual chillers or cooling towers, plus maintenance costs are pooled.
Being buried underground also has the social side-benefit of freeing up precious roof space in densely populated cities.
As the vast potential of district cooling and its role in achieving multiple socio-economic and environmental goals is revealed, cities around the world are waking up to the benefits.
People will always want to cool down in hot climates – district cooling offers them a more sustainable way to do it.