Energy-saving Cooling Ceramic for Building Exteriors


Low-cost self-cooling ceramic tile for building façade/roof, able to cut air-conditioning energy needs by >20% due to high broad-spectrum solar reflectivity (99.6%) and strong mid-infrared emission (96.5%).

  • Energy-saving Cooling Ceramic for Building Exteriors 0
  • Energy-saving Cooling Ceramic for Building Exteriors 1
  • Energy-saving Cooling Ceramic for Building Exteriors 2
Research completion
Commercialisation opportunities
Technology licensing agreement
Problem addressed

Our invention not only delivers advanced optical properties for generating cooling but also exhibits great applicability, which promises a readily applicable solution for passive radiative cooling.

  • We invented a passive radiative cooling ceramic material that can achieve record-high solar reflection of 99.6% and strong thermal emissivity of 96.5%.
  • The cooling ceramic topped with colored glazing, which breaks through the color limitation of traditional radiative cooling designs, still achieves better cooling performance compared with the same-colored commercial peers.
  • The cooling ceramic features high superhydrophilicity, which promises great self-cleaning capability and low-cost maintenance for long-term outdoor exposure.
Key impact
  • Electricity-free: the operation does not require electricity input.
  • Scalable: the manufacturing process is facile and compatible for mass production
  • Stability: long-term optical properties conservation with UV-resistance, superhydrophilicity and fire-resistance
  • Environmentally friendly: does not generate pollutants during the operation and the material is recyclable
  • 48th International Exhibition of Inventions Geneva (IEIG) - Silver Medal
  • Buildings: integration for pre-cooling purposes to reduce energy consumed by traditional air-conditioning systems
  • Thermal management enhancement for local microclimate
  • Thermal management of outdoor electronic devices to improve electricity utilization efficiency
  • Heat island effect mitigation by applying on infrastructure surfaces in urban areas, such as pavements


  • Patent number: 17/879,878 (USA) IDF 1218
City University of Hong Kong (CityU)

As one of the fastest growing universities in the world over the past decade, City University of Hong Kong (CityU) is recognised as a hub for innovation in research and professional education. CityU identifies solutions to critical global challenges by extending the frontiers of knowledge both within and beyond existing research paradigms.

The University’s highly qualified academics are drawn from all over the world, not only bringing a wealth of research and professional experience to the teaching programmes, but also contributing to the knowledge and technology advancement.