Dr. Edwin Tso, Assistant Professor, was recently invited by the Electrical and Mechanical Services Department (EMSD) of the HKSAR Government to give a presentation on “Daytime Passive Radiative Cooling in Hong Kong: Past, Present, and the Future” on 14 July 2021 at the lecture theatre of Hong Kong Science Museum. To promote energy saving and conservation, Dr. Tso introduced an advanced building energy-saving technology, namely daytime passive radiative cooling, to the government officials from various bureau/departments in the presentation.

Air-conditioning consumes over 30% of building energy consumption in Hong Kong. Compressors of traditional air-conditioning systems consume enormous amounts of energy and use ozone-depleting refrigerants, contributing to energy shortage and global warming. Conversely, passive radiative cooling technology has an edge in decarbonization and environmental protection since it is green (refrigerant-free) and sustainable (energy-free). In the past, radiative coolers were expensive and the feasibility of large-scale application in buildings was yet to be facilitated. Based on the situation, Dr. Tso and his research team developed an energy-free and low-cost passive radiative cooling paint, providing a promising energy-saving approach to electricity consumption in buildings. With excellent cooling performance and significant building energy-saving potential, this award-winning cooling paint attracted numerous interests from different sectors of society. In the future, Dr. Tso will investigate this technology in-depth to further functionalize the current passive radiative cooling paint. For example, the cooling paints with different colors, the water-based property, cooling power modulation ability, and even the coolers in a ceramic form, will be developed, providing more options to building users and contributing towards the zero-carbon goal.