This website provides consumer-oriented information about switchable electrochromic (EC) windows. Electrochromic windows change tint with a small applied voltage, providing building owners and occupants with the option to have clear or tinted windows at any time, irrespective of whether it's sunny or cloudy. EC windows can be manually or automatically controlled based on daylight, solar heat gain, glare, view, energy-efficiency, peak electricity demand response, or other criteria. Window controls can be integrated with other building systems, such as lighting and heating/cooling mechanical systems, to optimize interior environmental conditions, occupant comfort, and energy-efficiency.

This new technology is just entering the commercial market. To answer common consumer questions concerning this technology, this website provides information on:

• What are electrochromic windows?
  What do they look like, how fast do they switch, under what temperature conditions do they operate, what is their switching range?
• How does one design electrochromic windows for buildings?
  What sizes and shapes do they come in, how are they specified, how does one wire and control the window?
• What are the benefits of using electrochromic windows? How does one control the windows to obtain energy savings, how does one estimate energy benefits, what is the cost-benefit payback, what do people think of these windows?
  

The information and data presented in this website were derived from a three-year Lawrence Berkeley National Laboratory (LBNL) field study of early-market electrochromic windows completed in the Spring of 2006 (see Resources for more information). Although currently this website content focuses on tungsten-oxide EC windows with on-off control (fully bleached and fully colored states only) such as those now being offered by SAGE Electrochromics, Inc., results from the LBNL field study data for EC windows with intermediate state control (variable tint between fully colored and fully bleached) will be relevant as new product offerings become commercially available. Products from other manufacturers may also enter the market in the next few years.

The full content of this website can be downloaded as a PDF here [10.4 MB].

This work was supported by the California Energy Commission through its Public Interest Energy Research (PIER) Program and by the U.S. Department of Energy.