A museum in Rio de Janeiro draws in water from a nearby bay for cooling. Similarly, but at a bigger scale, Toronto’s downtown core has a cooling system that uses cool lake water to absorb heat from city buildings. A hospital in rural Bangladesh uses courtyards and canals to create a cooling microclimate. Architects in Singapore, the air conditioning capital of Southeast Asia, are angling buildings in ways that allow wind to flow through city blocks and using vertical gardens to cool high-end hotels and office buildings.
And then, there’s paint. Researchers are competing to develop white paint that reflects nearly all sunlight. The ones in use now still absorb around 15 percent of sunlight and the heat that comes with it.
Efforts to cool city neighborhoods aren’t always immediately popular. In Paris, a plan to cool the area around the Eiffel Tower is facing fierce opposition because it means knocking down trees, as my colleague Constant Méheut wrote.
Now more than ever, energy-saving innovations are needed. The Toronto cooling system saves enough electricity to power a town of 25,000 through a year, while the Rio museum’s cooling system consumes 50 percent less energy than a conventional one. In fact, a recent United Nations report estimates that a global, coordinated effort to make cooling more sustainable and efficient could avoid eight years’ worth of global emissions, based on 2018 levels, over four decades.
Make air-conditioners better
The Rocky Mountain Institute, a research group whose Colorado-based office generates more energy than it consumes, runs a competition to spur innovations in cooling. The two companies that won last year, Daikin and Gree, developed air-conditioners that use much less energy.
Why doesn’t every company do that? Electricity standards don’t require it yet, explained Iain Campbell, a cooling expert at the Rocky Mountain Institute, . Plus, it’s more expensive upfront. The prototypes developed by the two companies were two to three times pricier, Campbell said. “But over 10 years, using these machines would cost you half,” he added. They would simply use less electricity.