Innovative SARC coating cools buildings without electricity, combining sustainability and adaptivity

SARC (Solar-driven Adaptive Radiative Cooling) is a technology developed by researchers at Hong Kong Polytechnic University. It operates based on the principle of passive radiative cooling, where a building's surface emits heat as infrared radiation. This process lowers the surface temperature without the need for energy.

The technology is based on tiny carbon particles (carbon dots) that enable adaptive building cooling. By absorbing sunlight and emitting it as less energetic light, they become more efficient under intense sunlight. The coolant coating can be easily applied with a paint roller. Additionally, there is the option to produce SARC in various colors.

A study published in the Chemical Engineering Journal shows that the SARC coating is amazingly effective. A SARC-coated roof achieved a temperature reduction of 20°C compared to a conventional concrete roof. In addition, the temperature of the coating is reported to have been consistently lower throughout the day (from 8:30 am to 5:30 pm) compared to an uncoated roof.

Unlike traditional cooling methods for buildings, the coating requires no electricity, which can significantly lower energy consumption in homes equipped with air conditioning. Another advantage of the SARC coating is its environmental sustainability. The material is free of heavy metals, and the carbon dots used are non-toxic and biocompatible. While it is unclear when the coating will become commercially available, researchers are reportedly already working on a improved version that can cool buildings in the summer and provide warmth in the winter.