Intro Sentence:
UCLA researchers in the Department of Materials Science and Engineering have formulated a novel bilayer coating that enables high-performance passive daytime radiative cooling.
Background:
Conventional technologies for cooling buildings are highly energy-intensive, consuming about 19% of U.S. residential electricity and contributing to greenhouse gas emissions. Passive daytime radiative cooling (PDRC) has been proposed as a promising alternative. These solutions utilize highly solar reflective materials to reflect solar heat back into the atmosphere, cooling surfaces to below ambient temperatures even under direct sunlight. The result is a net loss of heat by radiating solar energy directly into space. Current PDRC solutions such as white “cool roof” coatings are limited by poor ultraviolet reflectance and rely on costly and environmentally unfriendly materials such as polyvinylidene fluoride (PVDF), limiting scalability and widespread deployment. Additionally, manufacturing of current materials is energy-intensive and may result in long-term pollution via the generation of per and polyfluoroalkyl substances (PFAS). Furthermore, these materials require thicknesses as great as 400 µm to achieve high solar reflectance values. These limitations highlight the need for an alternative cooling solution that is energy-efficient, cost-effective, and environmentally friendly.
Innovation:
Researchers at UCLA have developed a novel paint architecture for passive daytime radiative cooling that maximizes reflectance in the visible and near-infrared regions. The design results in a total coating thickness of approximately 75 µm and achieves a total solar reflectance exceeding 95%—a 5% improvement over comparable coatings—while significantly reducing reliance on costly PVDF. This innovation translates into lower cooling loads for buildings, reduced electricity demand from air conditioning, and corresponding decreases in greenhouse gas emissions. Importantly, the architecture is compatible with large-scale, low-cost paint manufacturing processes, offering a scalable and commercially viable pathway for adoption in residential, commercial, and industrial markets. By combining enhanced performance with material efficiency, this technology positions itself as a high-impact, energy-saving solution for sustainable cooling.
Potential Applications:
- Roof Coatings
- Exterior Wall Coatings
- Windows and facades
- Vehicle coatings
- Cars, trucks, trains, airplanes, etc.
- Defense
- Electronics
- Outdoor electronics: solar panels, towers, data centers, etc.
- Battery packs
- EV charging stations
- Urban Infrastructure
- Storage
- Any form of storage sensitive to temperature (chemical, liquid, etc.)
Advantages:
- Cooling performance
- >95% total solar reflectance
- Energy efficiency
- Cost-effective
- Sustainable
- Thin coating
Development-To-Date:
First successful demonstration of the invention
Related Papers:
Mandal, J., Yang, Y., Yu, N., & Raman, A. P. (2020). Paints as a scalable and effective radiative cooling technology for buildings. Joule, 4(7), 1350–1356. https://doi.org/10.1016/j.joule.2020.04.010
Reference:
UCLA Case No. 2026-014
Lead Inventor:
Aaswath Raman