CityU Unveils WITA Aerogel: Breakthrough Cooling Tech Cuts Temps by 5.2 Degrees
SingTao · 1 SOURCES1 day ago2 MIN
Summary
City University of Hong Kong (CityU) has achieved a breakthrough in cooling technology with the development of a white infrared-transparent aerogel (WITA) that can provide additional temperature reduction of up to 5.2 degrees Celsius when combined with sub-ambient daytime radiative cooling materials (SDRC). Research led by Professor Cao Zhiyin, Associate Dean and Chair Professor at the School of Energy and Environment, demonstrates how the new material decouples solar reflection from thermal radiation functions, overcoming limitations of existing cooling technologies. Outdoor experiments in Hong Kong and Abu Dhabi validate the technology's effectiveness, with building energy simulations indicating potential annual electricity savings of 14.6 gigajoules in hot climates.
Key Points
- The WITA aerogel achieves an atmospheric window transmittance of up to 94.5% and solar reflectance of 96.6%, using ultra-high molecular weight polyethylene as its substrate .
- In Hong Kong outdoor experiments, WITA-enhanced SDRC coatings delivered up to 5.2 degrees Celsius additional cooling compared to SDRC coatings alone .
- Abu Dhabi field tests confirmed that WITA SDRC coatings maintain superior cooling performance over extended periods under extreme desert conditions .
- Simulations for a four-story residential building in Abu Dhabi show WITA SDRC roofs could save 14.6 gigajoules of electricity annually, improving SDRC energy savings by approximately 55% .
- WITA offers additional advantages including long-term durability and good hydrophobic properties, making it suitable for various climatic conditions .
Why It Matters
For Hong Kong residents grappling with intensifying summer heat and urban heat island effects, this technology offers a passive cooling solution that requires no electricity consumption. Professor Cao Zhiyin noted that the research establishes a predictive framework linking material composition to building energy performance, potentially accelerating the deployment of radiative cooling technologies across the city's building sector .
For Hong Kong residents grappling with intensifying summer heat and urban heat island effects, this technology offers a passive cooling solution that requires no electricity consumption. Professor Cao Zhiyin noted that the research establishes a predictive framework linking material composition to building energy performance, potentially accelerating the deployment of radiative cooling technologies across the city's building sector .