APPLICATIONS OF TECHNOLOGY:
- Thermal regulation of residential and commercial buildings (i.e. roof or building envelope coating)
- Thermal regulation in environments with significant temperature variations (e.g., thermal radiator and coating for satellites or space stations in outer space)
- Mechanically flexible coating that adapts its thermal emittance to different ambient temperatures and to all surfaces and shapes
- Outperforms existing roof coatings for energy savings in most climates, especially those with substantial seasonal variations
- Much focus has been on maximizing the radiative cooling power of roof coating in the hot daytime using static, cooling-optimized material properties. However, the resultant overcooling in cold night or winter times exacerbates the heating cost, especially in climates where heating dominates energy consumption. There is a need for a technique that can automatically cease radiative cooling at low temperatures while enabling energy savings.
Researchers at Berkeley Lab have developed a smart roof coating technology for all-season household thermal regulation via a holistic approach.
They designed and fabricated a temperature-adaptive radiative coating (TARC) to minimize total energy consumption through the entire year. This coating structure has high flexibility for versatile surface adaption as well as a micro-scale structure consistent with the design. The TARC optimally absorbs solar energy and automatically switches its sky-window emittance to 0.90 from 0.20 when the surface temperature rises above ~22°C, a practical threshold not previously available. It delivers high radiative cooling power exclusively for the high-temperature condition.
Researchers also optimized the solar absorptance at ~0.25 for all-season energy savings in major U.S. cities. The energy savings by TARC not only bring economic benefits but also contribute to environmental preservation by reducing greenhouse gas emissions.
Progress has been recently made in scaling up TARC with roll-to-roll printing for meter-sized products.
DEVELOPMENT STAGE: Proven principle
FOR MORE INFORMATION:
- Junqiao Wu
- Kechao Tang
- Kaichen Dong
- Jiachen Li
STATUS: Patent pending.
OPPORTUNITIES: Available for licensing or collaborative research.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
A Photonic Near Infrared Heater for Efficiency and Comfort 2017-045
- Buildings and Energy Efficiency