Cooling solution without electricity

Dr. Winnie Tang August 27, 2024 22:10

It has been estimated that by 2070, the average annual temperature in Hong Kong will reach 26 degrees (24.5 degrees in 2023), and the weather will be very hot throughout the year. In face of extreme heat, everyone's most direct reaction is to switch on air conditioners, but most of the electricity is generated from burning fossil fuels, which is causing further rise in temperature.

That's why the World Economic Forum has selected one of the top 10 emerging technologies to address global challenges in 2024: sustainable cooling solutions.

At a time when the world is looking for alternatives to cooling, I am glad that a local startup i2Cool has been able to develop a solution without consuming electricity.

Earlier, I visited their base to experience first-hand the newly launched Hong Kong-patented energy-saving and decarbonisation cooling products, including car paints and films. Witness the successful reduction of the cabin and indoor temperature by 5 to 7 degrees Celsius, it is really amazing!

i2Cool is a technology startup incubated by City University of Hong Kong. Since 2016, the team has been developing this revolutionary cooling technology, which adds nanoparticles to different materials, such as paint, film and fiber fabric, to achieve cooling effect below ambient temperature through reflective sunlight and passive radiant heat dissipation, effectively saving energy and promoting carbon neutrality.

The inspiration for this technology came from the African silver ant in the Sahara Desert. The ant’s dense array of triangular silvery hairs on the top and sides of the bodies can reflect sunlight and dissipate heat to reduce heat absorption, allowing them to survive and thrive in high temperatures of 60 to 70 degrees.

In Hong Kong, the residents on the top floor of subdivided flats are among those most affected by the extreme heat. Last year, the team in collaboration with a local charity organisation applied the white iPaint to the roof of a 50-year-old building in Sham Shui Po. The residents there reported a drop in indoor temperature by 3 to 8 degrees, saving about 40% of their monthly electricity bills, and the shielding effect was still effective after one year.

At present, the startup has received support from a number of local government departments, public and private organisations, including public utilities, property developers and property management companies.

According to the company's website, the energy-free green solution has been used in more than 20 countries and regions such as the mainland, Southeast Asia, the Middle East, Europe and the United States, and are mainly used in construction, chemical industry, new energy, logistics, outdoor storage equipment and photovoltaic fields.

For example, in Abu Dhabi, United Arab Emirates, a company has used these cooling coatings on their shipping containers, reducing daytime temperature up to 30°C, helping to ensure the quality and freshness of goods, as well as to reduce electricity consumption.

The company's co-founders include Professor Christopher Chao, Vice-President and Chair Professor of Thermal and Environmental Engineering of The Hong Kong Polytechnic University; Professor Edwin Chi-Yan Tso, Associate Dean of the School of Energy and Environment at City University of Hong Kong (CityU); and Dr Martin Zhu, a PHD graduate of CityU.

I sincerely hope that this startup will continue to work hard to come up with more innovative solutions to make the world more sustainable and liveable.

Dr. Winnie Tang

Adjunct Professor, School of Computing and Data Science;Department of Geography, Faculty of Social Sciences, The University of Hong Kong