Martin Zhu, chief executive and co-founder, says the paint made by i2Cool was tested on the roof of a shopping center in Hong Kong – but only on one of its two buildings, to see if there had a notable effect in terms of reducing the operating costs of the air conditioning (AC) of this building.

“We used a power meter to measure the energy consumption of the air conditioning system,” says Dr. Zhu. The cost of running air conditioning actually fell by 40% in the painted building, he adds.

Dr. Zhu began working on the painting while he was a doctoral student, and he mentions that the first versions made around 2017 contained silver, making it very expensive – over $100,000 just to cover a small area. Years of development later, it now costs around $10 per square meter of roofing. It also now comes in a variety of light colors, including gray, yellow, and green.

The researchers noted that highly reflective coatings for passive cooling applications must be resistant to dirt, for example, to prevent their effectiveness from diminishing over time. And the glare from ultra-reflective roofs risks heating up darker structures nearby, causing Suggested 2020 article, external.

i2Cool’s paint does not contain heavy metals and uses a water-based emulsion. Although it is not biodegradable, it can be recycled, says Dr. Zhu.

The company’s latest major project is the Dubai Mall. The roof of this vast complex – the largest shopping center in the world by total area, external – will finally be completely covered with paint. A section of 1,000 m² has been completed to date.

Although it’s not yet available in Europe, that could change, says Dr. Zhu. “We are talking to some distributors in the UK,” he says.