APPLICATIONS OF TECHNOLOGY:
- Commercial and residential building fenestration
- Controls transmission of visible light
- Blocks infrared and UV radiation
- Minimizes heat gain outside the visible spectrum
- Maintains neutral color in clear state
Berkeley Lab researchers led by André Anders and Cesar Clavero have improved the properties of electrochromic windows with a novel design — called the switchable cavity window — that combines the visible light modulation of an electrochromic multilayer system with the multiple-cavity optical bandpass filter architecture to block heat from solar infrared and ultraviolet radiation. This combination of solar control and low emissivity is the sweet spot for smart window design, with greatest benefits for buildings in hot climates.
Current electrochromic window designs typically modulate visible light and solar infrared radiation; in their clear state, they let through most of the solar infrared radiation. In addition, their electrochromic switching operations are usually conducted by relatively thick (200 nm) transparent conducting oxide layers that serve as electrodes. The Berkeley Lab switchable cavity window, on the other hand, uses electrodes of thin metal films that are also components of the heat-blocking multiple cavity bandpass filter structure. This design provides the additional benefit of keeping a neutral color in the clear state while switching within the visible light range. This feature of meeting desired color perception is deemed critical for the commercial success of any window product.
DEVELOPMENT STAGE: Modeled concept
STATUS: Patent pending. Available for licensing or collaborative research.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
REFERENCE NUMBER: IB-2013-085