UmiCool: an Eco-friendly Smart Sub-ambient Radiative Cooling (SSRC) Coating

Making interior temperature in buildings cooler than ambient temperature without using electricity

UmiCool developed by PolyU researchers is an eco-friendly, self-cleaning, durable and cost-effective smart sub-ambient radiative cooling (SSRC) coating. The coating cools buildings under direct sunlight in summer without the use of electricity. The sub-ambient cooling effect is enhanced during daytime but suppressed during nighttime. Through combining particle scattering, sunlight-excited fluorescence, and mid-infrared broadband radiation, the coating can scatter sunlight, convert absorbed UV light to fluorescence emissions and re-emit infrared radiation to the cold universe. It provides an attractive solution to alleviate the power demands as well as negative environmental impact of building air-conditioning cooling. Its wider application can help mitigate global warming and urban heat island effect.

Special Features and Advantages

A unique single-layer daytime radiative cooling coating allowing heat to be transmitted into outer space through Earth’s atmospheric window, the coating has broadband emissivity-induced smart cooling, multiple-layer particle scattering and Purcell effect-enhanced fluorescent emission. Common construction materials are used in the coating, making it strong enough to withstand long-term weathering.

Applications

Building envelope such as roof and wall, in-situ office room, exhibition hall
Industry factory, storehouse, oil tank, airport covered bridge, pavement

Awards & Patents

Gold Medal - Special Edition 2022 Inventions Geneva Evaluation Days - Virtual Event (Mar 2022)
The 7th Guangdong–Hong Kong–Macau Greater Bay Area Youth Innovation & Entrepreneurship Competition
The 7th Hong Kong University Student Innovation and Entrepreneurship Competition (Entrepreneurship, Second Prize)

Patent Applications No.:

PCT/CN2020/124665
62/927,756 (US)

Principal Investigator

Prof. Jianguo DAI

Department of Civil and Environmental Engineering

Founder of Pro-Infra Science & Technology Limited
(a PolyU Academic-led start-up)

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Making interior temperature in buildings cooler than ambient temperature without using electricity