Hong Kong’s summer weather is scorching hot. Whether in shopping malls, offices, or homes, air conditioners are constantly running, causing harm to the planet and increasing electricity bills. In recent years, local startups have developed a technology for electricity-free cooling.
They incorporate cooling nanoparticles into paint to create a coating that radiates heat into outer space, achieving a cooling effect. This technology can be applied to roofs, building facades, and even developed into tiles, textiles, and more. It is expected to generate a business volume of HKD 200 million by 2025.
Dr. Wai Ka-bao, a lecturer in the Department of Health and Life Sciences at the Institute of Vocational Education (IVE) Shatin campus, mentioned that due to the hot summer weather in Hong Kong, air conditioners need to be run for extended periods of time.
As a result, many commercial buildings have installed heat insulation devices, such as applying heat insulation film to glass windows or installing double-layered glass with coated film for solar reflection and heat insulation. “Some new commercial buildings also have rooftop greening or solar panels installed. The latter not only reduces heat energy but also generates renewable energy, achieving dual benefits.”
Learn how Silver Ant “Keeping cool: Enhanced optical reflection and radiative heat dissipation in Saharan silver ants“
He pointed out that sustainable development is becoming increasingly important in Hong Kong. Listed companies are required to disclose their environmental performance annually, significantly increasing corporate ESG pressures. Therefore, most newly constructed commercial buildings are making efforts in energy conservation to obtain green certifications.
As Hong Kong has fewer manufacturing plants and needs to purchase energy-saving materials from abroad, it mostly uses internationally recognized environmentally friendly materials. “Of course, local universities also have their own research and apply for patents,” he explained.
Sunlight heats up the ground during the day, and at night, when there is no sunlight, the ground continues to emit heat, causing a decrease in ground temperature. This phenomenon, known as “radiative cooling,” is currently being utilized internationally to produce materials that cool and conserve energy.
Main Local Electricity Consumption: Air Conditioners
i2COOL’s CEO, Dr. Martin Chu Yihao (Martin), stated that their company primarily focuses on the research and development of electricity-free cooling technology. “The technology takes inspiration from the silver ants in the Sahara Desert. These ants have a unique hair structure that allows the dissipation of internal heat through mid-infrared methods into outer space.” Apart from reflecting sunlight, the technology can also radiate the heat from indoor spaces or electrical devices, penetrate the atmosphere, and enter outer space, thereby maintaining a cool temperature indoors or on the surface of equipment.
Martin began his research in collaboration with two university professors in 2015. In 2021, they successfully incorporated cooling nano-particles into paint, creating a coating. By 2022, they achieved mass production. “Hong Kong has a dense population and numerous buildings. According to the Electrical and Mechanical Services Department’s data, 90% of the local electricity is consumed by buildings, with over 30% attributed to the use of air conditioners.”
Martin’s coating can be applied to rooftops and exterior walls of buildings. It is priced 20% higher than ordinary white paint. Currently, the main customers are businesses (B2B). “Recently, places like Gala Place have used our coating during renovations. During the hottest summer days, it can reduce surface temperatures outdoors by up to 40 degrees and indoor temperatures by 10 to 15 degrees.
In comparison, ordinary white paint can only lower temperatures by 4 to 5 degrees, a difference of about twice as much.” The energy consumption of air conditioners in Gala Place’s two equipment rooms (one with the coating and one without) differs by 42%. In addition to building exteriors, the coating can also be applied to solar panels, cooling towers, and car paint, among other applications.
Improved Coating: Warm in Winter, Cool in Summer
Starting from September 2022, Martin officially began operating his company. Within just a few months, they received orders worth 3 million Hong Kong dollars, with half of them from the local market and the other half from Southeast Asia. “The coating works even better in the dry and hot climate of the Middle East, where it can lower the indoor temperature by 20 degrees.” At the end of May this year, a Middle Eastern agent signed a 5-year cooperation framework with them, amounting to 10 million US dollars.
However, to enter different global markets, refrigeration technology alone is not sufficient. “For example, in northern regions with scorching cold weather or countries with significant temperature differences, refrigeration technology may not be effective.” Therefore, Martin is currently improving the technology to make the coating darken with temperature and absorb sunlight for heating, saving 42% of electricity.
This will achieve the desired effect of keeping warm in winter and cool in summer. The mass production is expected to commence next year or the year after, with an annual production capacity of several thousand tons.
Learn how Silver ant hairs reflect sunlight, keeping Sahara dweller cool.
Revenue Reaches 20M
Given the limited land availability in Hong Kong, finding a suitable place for production is not easy. Therefore, Martin is currently manufacturing the coating in Guangzhou. “We have found a paint factory with excellent facilities. They allow us to use their space for free, while we purchase their paint to produce the coating. The monthly shipment value reaches 1 million Hong Kong dollars, benefiting both parties.”
As a startup company, Martin admits that hiring employees is also challenging. Therefore, they enhance their visibility by participating in various competitions, including the Trade Development Council’s “Start-up Express.” Additionally, they attend job fairs in mainland China. “We have participated 3 to 4 times, and the mainland government screens the participating companies and graduates. We receive about 20 CVs per day, and the quality is excellent.”
Speaking of future development directions, in addition to color-changing coatings, the team will also apply the technology to glass films, ceramic tiles, and textiles. “For example, applying it to umbrellas and tents, allowing a 10 to 15-degree cooling effect. In the future, there is even the opportunity to develop it for clothing.”
The products will be mass-produced within 1 to 3 years. Martin is very confident in the product, and solely based on the coating, their target revenue for this year is 20 million Hong Kong dollars, which is expected to reach 200 million Hong Kong dollars by 2025.