Mitigation of Heat Island Effect in Hong Kong Using Passive Radiative Cooling Materials (iPaint) - RMGS

The heat island effect is a well-known environmental problem in urban areas worldwide, including Hong Kong. The heat island effect is caused by human activities, such as buildings, roads, and transportation, that absorb and store heat from the sun, resulting in higher temperatures in urban areas compared to the surrounding rural areas. The consequences of the heat island effect in urban areas are significant and far-reaching. Higher temperatures can increase energy consumption for air conditioning systems, leading to increased greenhouse gas emissions and air pollution. The operation of air conditioning systems will further aggravate the heat island effect. High temperatures can also affect human health and well-being, leading to heat-related illnesses and increased mortality rates.Passive radiative cooling materials are emerging as a potential solution to mitigate the heat island effect in urban areas, creating a more comfortable urban microclimate. These materials can reflect the heat from solar irradiations and emit mid-infrared thermal energy to the cold universe, lowering the surface and indoor temperature for air conditioning energy-saving. Passive radiative cooling materials can be applied to various surfaces in the city, such as buildings’ roofs, walls, and pavements, reducing the heat absorption and emitting the heat radiation of the building construction materials, such as the concrete, to reduce the surface temperature and mitigate the heat island effect. Besides, using passive radiative cooling materials in buildings can have several benefits, including reduced energy consumption for air conditioning systems, improved indoor thermal comfort, and reduced greenhouse gas emissions. Furthermore, the application of these materials can contribute to sustainable urban development and enhance the quality of life for residents in urban areas.While previous research has shown the effectiveness of passive radiative cooling materials in energy saving and improving indoor thermal comfort for buildings, more research is needed to evaluate the performance of these materials in building-scale and city-scale real-world conditions, particularly in highly urbanized cities like Hong Kong. This proposed research project aims to evaluate the effectiveness of passive radiative cooling materials in mitigating the heat island effect in Hong Kong, providing guidelines and recommendations for the use of passive radiative cooling materials in urban planning and design in Hong Kong.