For the building and automobile industries in need of dark-colored products that can stay cool in the sun, this technology uses fluorescent materials that re-radiate absorbed light rather than converting it all to heat. The Berkeley Lab invention promises a solar reflectance over 0.5 in dark colors — a significant improvement over commercially available products.
APPLICATIONS OF TECHNOLOGY:
- Automobile finishes
- PVC piping
- Outdoor enclosures for electronics (e.g., cell phone towers)
- Meets industry and consumer demand for dark-colored building and automotive materials that stay cool in warm or hot climates
- Solar reflectance over 0.5
The building and automobile industries need to meet consumer demand for non-white or dark-colored products that can stay cool in warm and hot climates; however, their performance is limited by commercially available pigments that convert light from the visible spectrum to heat.
Paul Berdahl of Berkeley Lab has developed Dark-Colored Cool Pigments for Materials Exposed to the Sun. Unlike conventional technologies, the invention uses fluorescent pigments that re-radiate and reflect light from both visible and near-infrared (NIR) spectra rather than absorbing these light rays and converting them to heat. Because the invention is not limited to using white pigments, it will be possible to meet industry and consumer demand for non-white or dark-colored cool-roof materials, such as coatings, tiles, and roofing granules, as well as automobile paint.
The Berkeley Lab invention is a non-white coating with a solar reflectance of more than 0.5 — a significant improvement over commercially available non-white pigments — and will therefore remain cooler in the sun than conventional coatings pigmented with non-fluorescent particles.
With additional development, the technology would save consumers money by reducing their need for air conditioning during the summer, lowering residential and commercial building energy costs. Widespread use of the Berkeley Lab Dark-Colored Cool Pigments on residential and commercial rooftops also promises to lower outside air temperatures and potentially less smog.
DEVELOPMENT STAGE: Early stage.
STATUS: Issued U. S. Patent # 10,131,838. Available for licensing or collaborative research.
FOR MORE INFORMATION:
Zalich, M., Berdahl, P., “Fluorescent Pigments for High-Performance Cool Roofing,” 2014 Building Technologies Office Peer Review, U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy.
REFERENCE NUMBER: IB-3039