As global temperatures continue to rise and water shortages worsen around the world, a new type of paint has been developed that could help tackle both problems simultaneously.
During hot weather, living without air conditioning can be extremely difficult. However, in many places, electricity shortages, the absence of air conditioners, or financial constraints make it impossible for people to rely on cooling systems.
This is why scientists are working on alternative technologies that could reduce or even eliminate the need for air conditioning.
Scientists Chiara Neto and Meng Chao from University of Sydney have developed a nano-paint which, when applied to rooftops, can cool buildings while also collecting water from the air.
The pair founded Dew Point Innovations in 2022.
Buildings around the world are commonly constructed using concrete, and rooftops absorb a large amount of solar energy, making indoor temperatures significantly hotter. The company’s goal was to create a paint capable of substantially reducing heat absorption in urban areas.
To achieve this, they developed a white nano-material paint that reflects solar heat back into the atmosphere. This helps keep roof surfaces cooler than the surrounding air without requiring electricity.
Ordinary commercial white paint reflects around 70 to 80 per cent of sunlight, whereas the paint developed by Dew Point Innovations can reflect up to 96 per cent of sunlight.
As a result, the paint absorbs very little heat and can keep roof surfaces up to 6 degrees Celsius cooler than the surrounding environment.
The roof coating was tested in Sydney for three months in 2023. Researchers found that buildings coated with the paint remained noticeably cooler than those with traditional dark-coloured roofs, reducing air-conditioner usage by up to 34 per cent.
Another major advantage of the paint is its ability to collect water while cooling buildings without air conditioning. The coating can capture moisture from the atmosphere and store it as water.
During experimental trials, the system was able to collect up to 74 litres of water per day. Although this is not a replacement for conventional water supplies, it could help ease water shortages to some extent.
According to the company, the paint is expected to become commercially available in the future for use on residential rooftops.
The company is currently planning further trials and testing before launching the product on a commercial scale.
